PLC-5000 FULL SHUT-DOWN SYSTEM INSTALLATION AND …vaporless.com/installplc5000.pdf · The PLC-5000...

PLC-5000

FULL SHUT-DOWN SYSTEM

INSTALLATION AND OPERATION MANUAL

Central Control Node Software Version

6.3

Revision Date

August 5, 2003

Vaporless Manufacturing 8700 East Long Mesa Road

Prescott Valley, Arizona 86314

800-367-0185

ii PLC-5000 Full Shut-down System Installation and Operation Manual Rev 08-05-03

TABLE OF CONTENTS

SECTION I - INTRODUCTION System Concept ............................................................................................................................. 1-1

Power Line Communication ......................................................................................................... 1-1

3 GPH Leak Detection .................................................................................................................. 1-3

Precision Leak Detection .............................................................................................................. 1-3

Line Pressure Regulation .............................................................................................................. 1-3

Certifications ................................................................................................................................. 1-4

SECTION II – LEAK DETECTOR NODE Introduction ................................................................................................................................... 2-1

General Function ........................................................................................................................... 2-1

Packaging ...................................................................................................................................... 2-1

Pressure Sensing and Shunt Valve ................................................................................................ 2-1

Override Function ......................................................................................................................... 2-6

LDN Labeling ............................................................................................................................... 2-6

Installation Procedure for Single Phase Power Systems ............................................................... 2-7

Installation Procedure for Three Phase Power Systems ................................................................ 2-17

Remote Sensor Inputs ................................................................................................................... 2-21

SECTION III – CENTRAL CONTROL NODE Introduction ................................................................................................................................... 3-1

General Function ........................................................................................................................... 3-1

Packaging ...................................................................................................................................... 3-1

Input and Output Signals ............................................................................................................... 3-1

Installation ..................................................................................................................................... 3-4

SECTION IV – SPECIAL APPLICATIONS Introduction ................................................................................................................................... 4-1

Variable Speed Turbines ............................................................................................................... 4-1

Solenoid Actuated Shut-off Valve ................................................................................................ 4-1

Multi-Turbine Manifolds with Staged Turbine Starting ............................................................... 4-4

Option B — Mater–Slave Select ................................................................................................... 4-4

PLC-5000 Full Shut-down System Installation and Operation Manual iii Rev 08-05-03

SECTION V – SET-UP PROCEDURE Introduction ................................................................................................................................... 5-1

LonWorks Installation Philosophy ................................................................................................ 5-1

Installation Procedure .................................................................................................................... 5-1

Resilience Constant Measurement ................................................................................................. 5-3

3 GPH Leak Detection Test ........................................................................................................... 5-5

SECTION VI – SYSTEM OPERATION Introduction ................................................................................................................................... 6-1

System Hardware .......................................................................................................................... 6-1

Display Push-Button Keypad Printer Changing Printer Paper Changing Printer Ribbon

Turbine Sequence Control ............................................................................................................. 6-2

Basic Operating Sequence Variations of Turbine Sequence Control Control Valve (CV) Sequence Staged Turbine (ST) Sequence Variable Speed (VS) Sequence Option B Master-Slave Select

CCN State List ............................................................................................................................... 6-5

CCN Alarm List ............................................................................................................................ 6-6

Command Codes ........................................................................................................................... 6-7

Leak Test Protocols ....................................................................................................................... 6-9

Printout Formats ............................................................................................................................ 6-10

iv PLC-5000 Full Shut-down System Installation and Operation Manual Rev 08-05-03

TABLE OF ILLUSTRATIONS

Figure 1.1 Distribution Network Illustration .................................................................................... 1-2

Figure 2.1 Power Connection Schematic, 1-phase ........................................................................... 2-2

Figure 2.2 Power Connection Schematic, 3-phase ........................................................................... 2-3

Figure 2.3 LDN Physical Layout ..................................................................................................... 2-4

Figure 2.4 LDN Dimensions ............................................................................................................ 2-5

Figure 2.5 LDN Installation, 1-phase ............................................................................................... 2-8

Figure 2.6 LDN Installation, Exploded View, 1-phase .................................................................... 2-9

Figure 2.7 LDN wiring with starting capacitor mounted in turbine head ........................................ 2-12

Figure 2.8 LDN wiring with starting capacitor mounted in electrical panel .................................... 2-13

Figure 2.9 TMS System Modification .............................................................................................. 2-14

Figure 2.10 Control Box Modification ............................................................................................... 2-15

Figure 2.11 LDN Installation, 3-phase ............................................................................................... 2-18

Figure 2.12 LDN Installation, Exploded View, 3-phase .................................................................... 2-19

Figure 2.13 Sump Sensor Circuits ...................................................................................................... 2-22

Figure 2.14 Cable Connector Installation .......................................................................................... 2-23

Figure 2.15 Model PLC-5021 Label .................................................................................................. 2-24



Figure 3.1 CCN Dimensional Information ....................................................................................... 3-2

Figure 3.2 CCN Connector Location Diagram ................................................................................ 3-3

Figure 3.3 Power Mains and Authorization Signal Connections ..................................................... 3-5

Figure 4.1 Variable Speed Turbine System ...................................................................................... 4-2

Figure 4.2 Solenoid Activated Shut-off Valve ................................................................................. 4-3

Figure 4.3 Manifolded Two-turbine System .................................................................................... 4-5

Figure 4.4 Manifolded Three-turbine System .................................................................................. 4-6

Figure 6.1 Changing Paper Roll and Ribbon Cartridge ................................................................... 6-3

Figure 6.2 Configuration / Status Report Format ............................................................................. 6-11

Figure 6.3 Alarm Log Report Format .............................................................................................. 6-12

Figure 6.4 Precision Test Log Report Format .................................................................................. 6-13

PLC-5000 Full Shut-down System Installation and Operation Manual v Rev 08-05-03

vi PLC-5000 Full Shut-down System Installation and Operation Manual Rev 08-05-03

SECTION I - INTRODUCTION

SYSTEM CONCEPT 2. Upon receiving an authorization signal for fuel dispensing, the CCN will issue a command to the appropriate LDN to energize its turbine. The PLC-5000 Full Shut-down System monitors

and detects leaks in closed piping systems. Specifically, it is designed to meet Environmental Protection Agency (EPA) guidelines for gasoline station monitoring.

3. Using the mechanical leak detector, the system will perform a 3 gph leak test. If the LDN determines that proper line pressure has been achieved, it will communicate this status to the CCN. The CCN will then allow the dispensing of fuel.

The system is configured as a distributed control network composed of elements referred to as nodes. Each electronic node is capable of performing a specific task. The central control node functions as the master node in the network. The communication media in this network is the power mains. To restate this concept, all communication between central and remote nodes is carried on the same wires that provide power to the nodes of the network. Figure 1.1 illustrates the arrangement of nodes in a typical detection network.

4. If proper line pressure is not achieved, a 3 gph leak failure exists. Under this condition the CCN will signal the LDN to deenergize its turbine contactor and an appropriate alarm will be issued. This action represents one of the full shut-down modes of the system.

5. In addition, the CCN will also conduct a 3 gph leak test following completion of any dis-pensing sequence.

6. When requested, the CCN node will also con-duct precision leak testing at levels of 0.1 gph and 0.2 gph.

The basic function of the Central Control Node (CCN) is to monitor for product dispensing re-quests, monitor the activity of each of the remote Leak Detector Nodes, and determine the operation of the submersible pumps or turbines. Also, in the event of a detected leak or other error condition, the CCN will issue appropriate alarms.

POWER LINE COMMUNICATION

This shut-down system uses the site’s power lines as the communication pathway. The LonWorks protocol designed by Echelon Corporation has been selected for network communication. This standard is also used by the International Forecourt Standards Forum (IFSF), a group of oil companies backing the development of standards for the motor fuels retail sector.

The basic function of the Leak Detector Node (LDN) is to monitor pressure in the distribution line and communicate the status of the line to the CCN. The LDN also directly controls its associ-ated pump or turbine under instruction from the CCN. In addition, the LDN is capable of monitor-ing an optional sump sensor for the presence of liquids. This sensor may be of the type which discriminates between water and hydrocarbons (fuels).

LonWorks is a general purpose control network technology that can be used to monitor sensors and control outputs in a wide variety of applica-tions. Using LonWorks power line transceivers, control networks can be implemented through the same AC mains that power the equipment under supervision. Power line signaling eliminates the need for additional communications cabling both reducing the cost and simplifying the task of retrofitting control networks in existing installations.

As shown in Figure 1.1, mechanical leak detectors are also included in the monitoring system. A leak detector is connected to an LDN so that both line pressure and the status of the leak detector can be monitored. Also, there are additional benefits provided by the leak detector which are discussed in other sections of this manual.

Designed for worldwide application, the transceivers used by Vaporless meet the regula-tions for AC mains signaling of the FCC (Federal Communication Commission), Industry Canada (formerly DOC), and CENELEC (European Committee for Electrotechnical Standardization).

The following statements outline the basic opera-tion of the shut-down control system:

1. With power applied, the system is active and monitors for dispensing requests and alarm conditions.

PLC-5000 Full Shut-down System Installation and Operation Manual 1-1 Rev 08-05-03

Figure 1.1 Distribution Network Illustration

1-2 PLC-5000 Full Shut-down System Installation and Operation Manual Rev 08-05-03

The LonTalk Protocol follows the reference model for open systems interconnection (OSI) developed by the International Standards Organization (ISO) and provides services at all seven layers of the OSI reference model.

3 GPH LEAK DETECTION

The EPA’s regulations require operators to test for leaks on a routine basis (40 CFR Part 280, Subpart D). The regulations require that under-ground piping must be equipped with an auto-matic line leak detector that will alert the operator to the presence of a leak by restricting or shutting off the flow of fuel through the pipe or by trig-gering an auditory or visual alarm. This test is designed to detect the presence of very large leaks which may occur between the more accurate regularly scheduled monthly monitoring tests or annual line tightness tests.

The standard requires that a leak greater than 3 gph must be detected within one hour of its occurrence. The PLC-5000 System in combination with Vaporless family of mechanical leak detectors will meet and exceed these requirements.

PRECISION LEAK DETECTION

In addition to large leak detection requirements, the EPA regulations also require the periodic testing for much smaller leaks. The PLC-5000 Full Shut-down System provides for precision leak detection at levels of both 0.1 gph and 0.2 gph. Statistically based test regimes have been developed to monitor for and report leak rates referenced to the EPA standard of 0.1 gph at 45 psi. When a leak is detected, the quantified result of the test is presented to assist in the trouble-shooting process.

Fundamental to the operation of the precision leak detection system it is known that a specific volume of fuel must leave the distribution line for the pressure in the line to move from a specific higher pressure to a specific lower pressure. This volume is known as the resilience constant measured in milliliters. Since the volume is dependent on line characteristics such as length and flexibility, it must be measure for each line at a site.

Measuring the resilience constant is only the be-ginning. Precision leak detection in a distribution system is a complicated affair. Since gasoline and diesel fuels are not ideal fluids, that is, they can significantly expand and contract with temperature,

the protocols of leak detection must deal with many variables. These variables include the magnitude of the resilience constant; measurement error associated with the resilience constant; the size of the leak (if any is present); the thermal conditions encountered by the fuel transferring from the storage tank to the distribution line; the thermal transfer characteristics of the distribution line which is influenced by the type of line material, depth of burial, moisture content of the sur-rounding soil, type of soil and ambient tempera-ture; and the EPA requirements of reporting results at better than a 95% probability of detecting the leak, and less than 5% probability of declaring a leak when the actual leak rate is less than the detection threshold. The protocols in the PLC-5000 deal with these issues.

LINE PRESSURE REGULATION

In a dispensing system provision must be made to limit the pressure in the line. This is necessary for two reasons. First, excessive pressure may create a leak by blowing out seals or rupturing fittings. Second, some types of dispensing nozzles will not open under high line pressure conditions.

It is important to note that Vaporless mechanical leak detectors contain a check valve which prevents fuel from flowing from the line, through the turbine and back into the supply tank. This check valve allows pressure to be maintained and controlled in specific ways necessary for the proper functioning of the Shut-down System.

Contained within the LDN is a solenoid operated valve which under system control can shunt fuel from the pressurized line back to the tank. Following a dispensing operation, the shunt valve is used to reduce line pressure to an acceptable level. This valve is also used to reduce excessive line pressure caused by thermal expansion of fuel in the line. It is also used to adjust line pressure during electronic line leak testing.

THIRD PARTY EVALUATION

Ken Wilcox Associates conducted tests to verify the performance of the PLC-5000 Full Shut-down System. Results of the tests are presented in their report titled Evaluation of PLC-5000 Site Controller with Automatic Electronic Line Leak Detection with the 98 LD-2000 and 98 LD-2000 PLC Mechanical Line Leak Detectors; Final Report, May 20, 1998.


Quoting from the Conclusions:

• The Vaporless PLC-5000 Line Leak Detection System exceeds the EPA performance re-quirements for hourly testing and annual line tightness testing.

• In the monthly monitoring/annual line tight-ness test mode, the probability of detection of a 0.1 gph leak is 100% and the probability of false alarm on a tight line is 0%.

Questions regarding this evaluation should be directed to Vaporless Manufacturing.

APPLICATION APPROVALS

The PLC-5000 Full Shut-down System has been approved by specific localities for application within their jurisdiction. Questions regarding regulation and application should be directed to Vaporless Manufacturing.

SAFETY APPROVAL (PENDING)

The PLC-5000 family of Leak Detector Nodes has been approved for operation in Class I, Division 1, Group D hazardous environments by Underwriters Laboratories. The product is listed under Process Control Equipment for Hazardous Locations, Control Number 47LL.


SECTION II — LEAK DETECTOR NODE

INTRODUCTION Table 2.1 — LDN Model Numbers

This section presents specific information regard-ing the function, physical characteristics and in-stallation of the Leak Detector Node (LDN). The basic function of the LDN is to monitor pressure in the distribution line and communicate the status of the line to the Central Control Node (CCN). The LDN also directly controls a pump or turbine under direction from the CCN. In addition, the LDN is capable of monitoring an optional sump sensor for the presence of liquids. This sensor may be of the type which discriminates between water and hydrocarbons (fuels).

Model Number Turbine Size

(Max Hp)

Power

(Phases)

PLC-5021 2 1

PLC-5031 5 3

PLC-5041 10 3

PACKAGING

The LDN is packaged in a custom explosion proof and water-tight enclosure designed to function in a Class I, Division 1, Group D hazardous environment. As indicated in Table 2.2, an installation kit is available which will maintain the integrity of the device. However, it is the responsibility of the installer to provide an appropriate configuration which meets National Electrical Code and local code requirements. Additional information regarding installation of the LDN is available in this section of the manual.

Up to four Leak Detector Nodes may be present in the network controlled by a single Central Control Node. An LDN functions as a slave node in the network.

GENERAL FUNCTION

An LDN controls only the single turbine and monitors the pressure of only the single distribu-tion line to which it is connected. Appropriate hardwired inputs and outputs are provided for connection to the power mains and turbine. Addi-tional intrinsically safe inputs are provided for the optional sensor which may be connected to the node through the circular connector located on the LDN enclosure.

Table 2.2 — LDN Installation Kits

LDN Model Number

Installation Kit Part Number

PLC-5021 PLC-5025 (Red Jacket)

PLC-5021 PLC-5026 (FE Petro)

PLC-5031 PLC-5035

PLC-5041 PLC-5045

The application software resides in the program memory section of the microcontroller which forms the central operating unit of the LDN. This custom software controls the sequence of opera-tions performed by the LDN and is not available to the user for modification.

Figure 2.3 illustrates the accessible parts of the unit. Figure 2.4 provides dimensional information for each model in the family of products.

Various members of the LDN family of nodes are designed to operate from single phase or three phase power mains depending upon the size of the turbine load. Figure 2.1 is a schematic illustrating power connections in a single phase system, while Figure 2.2 is illustrates power connections in a three phase system.

PRESSURE SENSING AND SHUNT VALVE

Because the system performs its function by monitoring pressure, it is necessary to have a pressure connection from the line, or the line side of the mechanical leak detector, to the LDN. As illustrated in Figures 2.1 and 2.2, 1/4” copper tubing is installed between the LDN and the pres-sure source, and between the LDN and the vent port of the leak detector.

Table 2.1 lists the various model numbers within the LDN family of products. The various models differ only in the size of the applicable motor load and the number of power phases. Note that all of the LDN models are powered from a nominal 230 VAC (208 - 240 VAC).


Figure 2.1 Power Connection Schematic, 1-phase


Figure 2.2 Power Connection Schematic, 3-phase


Figure 2.3 LDN Physical Layout


Figure 2.4 LDN Dimensions


As described in Section I – Line Presssure Regulation, the LDN contains a solenoid operated valve which under system control can shunt fuel from the pressurized line back to the tank. The copper lines illustrated in Figures 2.1 and 2.2 are also used for this purpose. When the valve is open, fuel is allowed to flow from the pressurized line back to the tank.

means that the turbine will run whenever power is applied to the LDN.

When an LDN is in the override mode, the system will be incapable of detecting certain alarm conditions. This is considered to be a temporary situation which will be corrected by the timely replacement or repair of the defective elements within the system. It is the responsibility of the operator and technician to ensure timely service.

OVERRIDE FUNCTION It should be noted that even when the override switch is in the engaged position, the mechanical leak detector still performs its normal function. The function of the mechanical leak detector cannot be overridden.

While good design practice has been employed in the development of the control circuits and the selection of components, failure of components may happen from time to time. With this in mind, provision has been made to override the turbine contactor output in order to ensure a method of continued operation of the facility. The override function is engaged using a toggle switch located on the side of the LDN enclosure.

Additional information regarding the override function may be found in the section discussing operation of the total system.

LDN LABELING Figure 2.3 indicates the location of the 3/4 NPT hole plug used to protect and seal the switch. The LDN must not be operated with the plug removed. This will void both the explosion proof and water-tight features of the enclosure.

Figures 2.15, 2.16 and 2.17 illustrate the labels attached to the PLC-5020, PLC-5030, and PLC-5040 respectively. The following information is presented on each label:

• Model and serial numbers The override function may be used to bypass the functions of the LDN when an electronic system failure has disabled the control system. The over-ride function may also be used to provide a means of troubleshooting and system testing to prove the function of various sub-systems.

• Voltage, current and load specifications • Summary of connector and port locations • Location and direction of the override switch • Hazardous environment classification • Warnings and cautions regarding operation With the switch toggle in the down position the

LDN will operate in its normal mode. With the toggle in the up position the LDN will be in the override mode. While in the override mode the control circuits of the LDN will remain unpow-ered and the coil of the turbine contactor will be energized directly from the power mains. This

• Note regarding communication installation • Reference to the installation control drawing • Safety approval notation

The installer should be familiar with the information presented on the label.


INSTALLATION PROCEDURE FOR

TECHNICAL NOTE — This procedure is designed to produce both an explosion proof and watertight installation. Application of sealing compound is required as noted.

SINGLE PHASE POWER SYSTEMS

The installation procedure for a single phase power system is slightly different than that for a three phase system. The following procedure ap-plies to single phase systems only.

TECHNICAL NOTE — The voltage for all nodes in the network must be derived from the same power phase.

As indicated in Table 2.2, an installation kit is available from Vaporless which will maintain the integrity of the LDN while operating in a hazard-ous environment. However, it is the responsibility of the installer to provide an appropriate configu-ration which meets National Electrical Code and local code requirements.

Figures 2.5 and 2.6 illustrate the basic arrange-ment of components in an installation using the PLC-5025 or 5026 kits. Some modification may be required to deal with specific problems pre-sented by a particular installation. Following is a list of materials supplied in the

PLC-5025 and 5026 installation kits.

TECHNICAL NOTE — DO NOT rotate the elbow from which the wires exit the side of the LND. Doing so may permanently damage the control unit.

List of Supplied Materials

Qty Description 1 1/2 NPT 90º pulling elbow 1 1/2 NPT 2-port conduit outlet box

1. Apply sealing compound to the 1-1/2” nipple and assemble the bushing, nipple and half of the union. Do not forget to include the union’s capture ring.

1 1/2 NPT male union 1 1/2 sched 40 galvanized nipple x 1-1/2” lg 1 1/2 sched 40 galvanized nipple x 6” long 1 1/2 sched 40 galvanized nipple x 8” long 1 1/2 sched 40 galvanized nipple x 12” long 2. Remove the plug from the turbine’s wiring

junction box. 1 2 x 1/2 NPT bushing (PLC-5025 only) 1 2-1/2 x 1/2 NPT bushing (PLC-5026 only)

3. If the motor starting capacitor is located in the turbine head, two wires will enter the junction box. These wires are the power mains and are connected to the motor wires which exit the box. Disconnect the wire pairs. It may be helpful to identify the wires for matching purposes. Figure 2.7 illustrates the wiring scheme with the capacitor in the turbine head.

1 Mounting bracket, short 2 Bolt, 1/4-20 x 1/2, hex 2 Lockwasher, split-ring, 1/4 1 Bolt, 1/2-13 x 2, hex 1 Lockwasher, split-ring, 1/2 2 Tubing, 1/4” copper, 24” long 1 Fitting, 1/4 tube x 1/8 NPT male, straight 1 Fitting, 1/4 tube run x 1/4 NPT male branch tee 1 Magnet (Used for communication installation) 4. If the motor starting capacitor is located in the

electrical panel, three wires will enter the junction box. These wires are the power mains and one end of the starting capacitor and are connected to the three motor wires which exit the box. Disconnect the wires from the power mains. Do not disconnect the wire from the starting capacitor. It may be helpful to identify the wires for matching purposes. Figure 2.8 illustrates the wiring scheme with the capacitor located in the control panel.

Additional Required Materials Heavy duty thread sealing compound with Teflon Wire nuts or splices Installation Procedure

TECHNICAL NOTE — Removing hole plugs from the turbine housing is the most difficult part of the installation procedure. Experience has shown that the use of proper tools for removing the plugs will significantly reduce installation time. A pipe wrench or adjustable wrench are not necessarily the proper tool. A socket and T-bar handle are recommended.

5. Extend each of the exposed wires about 12 inches. 14 gage wire is recommended; in this case bigger is not better. Use either wire nuts or splices to connect the wire ends.


Figure 2.5 LDN Installation, 1-phase


Figure 2.6 LDN Installation, Exploded View, 1-phase


The following color code is used in single phase LDN installations:

14 Feed the four wires from the turbine through the upper union and into the junction box.

Black AC L1 15. Rotate the junction box assembly, being care-ful not to damage the wires at the union tran-sition, so that the two halves of the union mate and secure the union connection.

White AC L2 Red One side of motor (switched L1) Orange One side of motor (switched L2)

6. Apply sealing compound to the external threads of the bushing, feed the four extended wires through the bushing assembly and screw the bushing into the top of the turbine’s wire junction box.

16. Using wire nuts, connect the wires in the junction box according to the color coded functions noted in step 5.

17. Install the caps on the pulling elbow and the junction box. The application of grease to the cap threads is recommended. 7. Mount the LDN to the turbine using the tri-

angular mounting bracket. The bracket at-taches to the LDN using the two 1/4-20 x 1/2” bolts and lockwashers. This assembly then mounts to the turbine housing using one of the turbine casing bolts. A 1/2-13 x 2” bolt and lockwasher are supplied to replace the existing bolt which may be too short to satis-factorily complete this installation.

18. If not previously completed, install the LD-2000 Leak Detector.

TECHNICAL NOTE — DO NOT apply sealing compound or tape to the fittings for the copper tubing. To do so may introduce contamination which will foul the shunt valve.

8. Apply sealing compound to one end of the 12” nipple. Feed the four wires from the LDN through this section of pipe and screw the nipple into the conduit elbow on the side of the LDN.

19. If not previously completed, screw a 1/4 tube x 1/8 NPT male straight fitting into the vent port of the LDN. This port is marked with two dots and is the port closest to the back of the LDN. DO NOT apply sealing compound or tape to this fitting. 9. Apply sealing compound to the exposed end

of the just installed nipple. Feed the four wires through one side of the pulling elbow and screw the elbow onto the exposed end of the 12” nipple.

20. If not previously completed, screw a 1/4 tube x 1/8 NPT male straight fitting into the pressure port of the LDN. This port is marked with one dot and is the port closest to the cover of the LDN. DO NOT apply sealing compound or tape to this fitting.

10. Apply sealing compound to the male threads of the remaining portion of the union and screw it into the bottom of the junction box.

21. Develop and implement a method of connecting a 1/4 tube x 1/8 NPT male fitting to the pressurized line down stream from the Leak Detector. Contact the factory for suggested solutions to this problem.

11. Select one of the two remaining nipples which will correctly span the distance be-tween the pulling elbow and the junction box which will eventually mount above the bush-ing assembly. Apply sealing compound to one end of the nipple and screw this section into the side of the junction box.

22. Screw the 1/4 tube x 1/4 NPT tee fitting into the top of the Leak Detector. Sealing com-pound may be carefully applied to the fit-ting’s threads. 12. Apply sealing compound to the exposed end

of the just installed nipple. Screw this as-sembly into the open end of the pulling elbow. At this point slight adjustments in the angle and fit of various components may need to be made to allow for the future connection of the two union pieces.

23. Install 1/4 copper tubing between the pres-sure takeoff and the LDN’s pressure port.

TECHNICAL NOTE — It is recom-mended that a small pore, large surface area fuel filter be placed in the pressure line. Contact the factory for recommendations. 13. Feed the four LDN wires through the pulling

elbow and into the junction box.


24. Install 1/4 copper tubing between the tee fitting on the Leak Detector and the vent port on the LDN.

If the turbine was controlled through a Red Jacket or FE Petro remote control box, jump-ers may be applied across the relay contacts or on the terminal barrier strip as illustrated in Figure 2.10. 25. Screw the straight tube fitting supplied with

the Leak Detector into the tank test port on the turbine housing. Sealing compound should be carefully applied to the fitting’s threads. Install 1/4 copper tubing between the remaining connection on the tee fitting and the tank test port fitting.

TECHNICAL NOTE — Rather than in-stalling jumpers, power could be supplied to the LDN by rearranging the power wir-ing. This approach is not recommended. While in the override mode the coil of the turbine contactor in the LDN will be ener-gized directly from the power mains. To re-establish cycling control of the turbine, the power circuit wiring will need to be returned to its original configuration. The presence of jumpers makes the re-establishment of the original circuit obvious and easier to implement.

TECHNICAL NOTE—The turbine’s tank test port is used as a none pressurized re-turn to the tank for the LDN vent. If such a port is not available, a return to the tank must be developed. Tapping into the turbine riser pipe, the fill tube, a fuel monitor riser pipe, a vapor recovery riser pipe, the cap on any such pipes, or an unused bung might be options to consider.

TECHNICAL NOTE — The circuit driv-ing the coil of a control relay should not be disturbed. This circuit will be extended during the installation of the Central Control Node.

26. To supply continuous power to the LDN, modifications must be made to the existing control circuits. If the turbine was controlled by a control relay, install wire jumpers across the contacts of the existing relay as illustrated in Figures 2.1, 7 and 8. 27. This completes the mechanical and electrical

portions of the installation procedure for sin-gle phase systems. The magnet is used during the communication set-up procedure.

If the turbine was controlled through a TMS system, move the turbine power lead as shown in Figure 2.9.


Figure 2.7 LDN wiring with starting capacitor mounted in turbine head


Figure 2.8 LDN wiring with starting capacitor mounted in electrical panel


Figure 2.9 TMS System Modification


Figure 2.10 Control Box Modification


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INSTALLATION PROCEDURE FOR TECHNICAL NOTE — DO NOT rotate the elbow from which the wires exit the side of the LND. Doing so may permanently damage the control unit.

THREE PHASE POWER SYSTEMS

The installation procedure for a three phase power system is slightly different than that for a single phase system. The following procedure applies to three phase systems only. 1. Remove the cover from the conduit junction

box. Three wire will enter the junction box. These are the three phase power mains and are connected to the three motor wires which exit the box. Disconnect the wire pairs. It may be helpful to identify the wires for matching purposes. Reconnecting the wires in the wrong order will cause the motor to run in the reverse direction and not deliver its specified volume.

As indicated in Table 2.2, an installation kit is available from Vaporless which will maintain the integrity of the LDN while operating in a hazard-ous environment. However, it is the responsibility of the installer to provide an appropriate configu-ration which meets National Electrical Code and local code requirements.

Following is a list of materials supplied in the PLC-5035 and 5045 installation kits. 2. Remove the existing junction box and

replace it with a 3-port junction box (not supplied with kit). The new box has an additional conduit port which will allow for proper installation of the LDN. Alternatively, appropriate tapping of the existing box may produce the required additional port.

List of Supplied Materials

Qty Description

2 1/2 NPT 90º pulling elbow 1 1/2 NPT male union 1 1/2 x 3/4 NPT reducer 1 Mounting bracket, long 3. At this point, the installation includes the

new junction box with the three power mains wires and the three motor wires entering the box. One port is still unused.

2 Bolt, 1/4-20 x 1/2, hex 2 Lockwasher, split-ring, 1/4 1 Bolt, 1/2-13 x 2, hex 1 Lockwasher, split-ring, 1/2 4. The following color code is used in three

phase LDN installations: 2 Fitting, 1/4 tube x 1/8 NPT male, straight 1 Magnet (Used for communication installation)

Black AC L1 Blue AC L2 Additional Required Materials White AC L3

3/4 NPT 3-port conduit outlet box Red One motor phase (switched L1) 1/2 sched 40 galvanized nipples of various lengths Yellow One motor phase (switched L2) 1/4” copper tubing Orange One motor phase (switched L3) Heavy duty thread sealing compound with Teflon

5. Mount the LDN to the turbine using the tri-angular mounting bracket. The bracket at-taches to the LDN using the two 1/4-20 x 1/2” bolts and lockwashers. This assembly then mounts to the turbine housing using one of the turbine casing bolts. A 1/2-13 x 2” bolt and lockwasher are supplied to replace the existing bolt which may be too short to satis-factorily complete this installation.

Wire nuts or spices

Installation Procedure

TECHNICAL NOTE — This procedure is designed to produce both an explosion proof and watertight installation. Application of sealing compound is required as noted.

TECHNICAL NOTE — The voltage for all nodes in the network must be derived from the same power phase.

6. Using the union and elbows supplied with the kit along with galvanized nipples of various lengths (not supplied with kit), construct a conduit system resembling that illustrated in Figure 2.11. Some modification may be re-quired to deal with the specifics of a particular installation. Apply sealing compound at all joints. The six wires exiting the LDN must be fed through the conduit during assembly.

Figures 2.11 and 2.12 illustrate the basic arrange-ment of components in an installation using the PLC-5035 or 5045 kits. Some modification may be required to deal with specific problems pre-sented by a particular installation.


Figure 2.11 LDN Installation, 3-phase


Figure 2.12 LDN Installation, Exploded View, 3-phase


7. Using wire nuts, connect the wires in the junction box according to the color coded functions noted in step 4.

the turbine housing. Sealing compound should be carefully applied to the fitting’s threads. Install 1/4 copper tubing between the remaining connection on the tee fitting and the tank test port fitting. 8. Install the caps on the pulling elbow and the

junction box. The application of grease to the cap threads is recommended.

TECHNICAL NOTE — The turbine’s tank test port is used as a none pressurized return to the tank for the Leak Detector and LDN vents. If such a port is not available, a return path to the tank must be developed. Tapping into the turbine riser pipe, the tank fill tube, a fuel level monitoring riser pipe, a vapor recovery riser pipe, the cap on any such pipes, or an unused bung might be options to also consider.

9. If not previously completed, install the LD-3000 High Capacity Leak Detector.

TECHNICAL NOTE — DO NOT apply sealing compound or tape to the fittings for the copper tubing. To do so may introduce contamination which will foul the shunt valve.

10. If not previously completed, screw a 1/4 tube x 1/8 NPT male straight fitting into the vent port of the LDN. This port is marked with two dots and is the port closest to the back of the LDN. DO NOT apply sealing compound or tape to this fitting.

17. To supply continuous power to the LDN, modifications must be made to the existing control circuits. If the turbine was controlled by a control relay, install wire jumpers across the contacts as illustrated in Figures 2.2.

11. If not previously completed, screw a 1/4 tube x 1/8 NPT male straight fitting into the pressure port of the LDN. This port is marked with one dot and is the port closest to the cover of the LDN. DO NOT apply sealing compound or tape to this fitting.

If the system was controlled through some other means, apply jumpers as necessary to provide continuous power to the LDN.

TECHNICAL NOTE — Rather than in-stalling jumpers, power could be supplied to the LDN by rearranging the power wir-ing. This approach is not recommended. While in the override mode the coil of the turbine contactor in the LDN will be ener-gized directly from the power mains. To re-establish cycling control of the turbine, the power circuit wiring will need to be returned to its original configuration. The presence of jumpers makes the re-establishment of the original circuit obvious and easier to implement.

12. Remove the 1/8 NPT plug for the line pres-sure port on the side of the main body of the Leak Detector. Install the 1/4 tube x 1/8 NPT male 90º fitting. Sealing compound should be carefully applied to the fitting’s threads.

13. Screw the 1/4 tube x 1/4 NPT tee fitting into the vent port on the top of the Leak Detec-tor’s cap. Sealing compound should be care-fully applied to the fitting’s threads.

14. Install 1/4 copper tubing between the 90º fitting in the pressure port of the Leak De-tector and the pressure port on the LDN.

TECHNICAL NOTE — The circuit driv-ing the coil of a control relay should not be disturbed. This circuit will be extended during the installation of the Central Control Node.

TECHNICAL NOTE — It is recom-mended that a small pore, large surface area fuel filter be placed in the pressure line. Contact the factory for recommendations.

15. Install 1/4 copper tubing between the tee fitting on the Leak Detector’s vent port and the vent port on the LDN.

18. This completes the mechanical and electrical portions of the installation procedure for three phase systems. The magnet is used during the communication set-up procedure.

16. Screw the straight tube fitting supplied with the Leak Detector into the tank test port on


REMOTE SENSOR INPUTS

In all cases, the voltage to power the sensor circuit is supplied from the node and meets UL intrinsic safety requirements.

The LDN incorporates inputs which monitor a remote sump sensor. A variety of sensor configu-rations are possible as described below.

Single point sensors provide reliable monitoring of a containment sump for the intrusion of liquids. These sensors typically contain magnetic float and reed switch liquid level detectors. Single point sensors that incorporate a polymer element can also be accommodated by the LDN.

Sump Sensor

The sump sensor input is generally used to moni-tor a turbine containment sump. Figure 2.13 illus-trates sensor circuits which may be connected to the sump sensor input. The circuits include single, dual and discriminating sensor configurations. In all cases, activation of the low input will produce a caution alarm. This type of alarm serves as a warning to the presence of liquid. Activation of the high input will produce a service alarm. This type of alarm results in a turbine shut-down since sump capacity requirements have been violated or the presence of hydrocarbon (fuel) has been de-tected. The turbine will remain disabled until the fault condition is cleared. All alarms relating to this input are referred to as sump alarms when reported on the display or printout.

Dual point sensors are used to detect two levels of liquid intrusion into a sump. These sensors typi-cally contain magnetic float and reed switch liquid level detectors. Dual point sensors that incorporate polymer elements can also be accommodated.

Discriminating sensors also provide reliable monitoring of containment sumps. Not only will these sensors detect liquid levels, but the sensors can discriminate water from hydrocarbons. These sensors typically combine magnetic float and reed switch liquid level detectors with a polymer strip that reacts to hydrocarbons.

Series and Parallel Combinations Any change in the status of the sensor will be re-ported to the CCN and recorded with a time and date stamp. As indicated in the following circuit diagrams, the LDN is also capable of detecting the presence or absence of a sensor attached to the sump inputs. Disconnect and reconnect of a sensor will also be reported to the CCN and recorded with a time and date stamp.

Various series and parallel combinations of sensors are possible. Please contact Vaporless to discuss your particular application.

NOTE — The mating cable connector for the sensor ports is available from Vaporless. Please contact us. We would be please to discuss your particular requirement. In the following illustrations all switches are

shown in their inactivated position, that is, with-out the presence of liquid. Note that some switches are shown as normal open while others are normal closed. Polymer elements are charac-terized by their resistance.

NOTE — Figure 2.14 illustrates the procedure for attaching the connector to the cable.


Figure 2.13 Sump Sensor Circuits


Figure 2.14 Cable Connector Installation


Figure 2.15 Model PLC-5021 Label






SECTION III — CENTRAL CONTROL NODE

INTRODUCTION PACKAGING

This section presents specific information regard-ing the function, physical characteristics and in-stallation of the Central Control Node (CCN). The basic function of the CCN is to monitor for product dispensing requests, monitor the activity of each of the remote Leak Detector Nodes, and determine the operation of the submersible pumps or turbines. Also, in the event of a detected leak or other error condition, the CCN will issue appropriate alarms.

The CCN is packaged in a custom enclosure which meets NEMA1 standards. It is not designed to operate in a classified environment.

The enclosure is provided with mounting holes which allow it to be secured to a wall or mounting board with screws. Also, four holes for conduit connections are provided on the bottom and both side panels.

The control circuits are contained on a single printed circuit board (PCB) secured in the enclo-sure. Field termination to this PCB are made to connectors along the edges of the PCB. These connectors are of a plug-in type which allows for removal without disconnecting the wiring. This eases both initial installation and field service.

The Central Control Node can manage the opera-tion of up to four Leak Detector Nodes. A CCN functions as the master node in the network.

GENERAL FUNCTION Figure 3.1 provides dimensional information for the CCN, while Figure 3.2 indicates the location of the various connectors on the controller circuit board.

The model PLC-5010 Central Control Node is capable of simultaneously monitoring and con-trolling up to four product channels. In its role as the master node in the network, the CCN receives requests for dispensing operations, directs the appropriate LDN to energize its turbine, monitors for proper line pressure conditions, controls pre-cision test protocols, and issues alarms when error conditions exist. The CCN is the heart of the PLC-5000 Full Shut-down System.

INPUT AND OUTPUT SIGNALS

Four classes of signals or devices are generally connected to the controller — power mains, dis-pensing authorization requests, channel sequenc-ing options and remote controlled devices such as line shut-off solenoid valves. Each of these signals or types of devices will be addressed in the following paragraphs.

The application software which directs the actions of the controller resides in the non-volatile memory coupled to the microcontroller. This custom software is not available to the user for modification.

Regarding the mounting location of the CCN, the following general statement can be made — the CCN should be located so that it is not only accessible by the operator, but is also in the vicinity of the signals that must be connected to the controller. As each of the signals and device types are discussed, a better understanding of the preceding statement will be developed.

The CCN is capable of controlling all of the members of the Leak Detector Node family of products. Different models of LDNs may be pre-sent in the same network.

The CCN is designed to operate from a single phase of a nominal 230 VAC power mains. The input voltage may range from 208 to 240 VAC. Figure 2.1 is a schematic illustrating power con-nections in a single phase power system, while Figure 2.2 is a schematic illustrating power con-nections in a three phase system. Note that in a three-phase system the voltage for the CCN is taken from the same phase that connects to the black and white leads of the LDNs.

Power Mains

The CCN operates from a single phase of nominal 230 VAC power mains. This single phase must be in common with that used to power the turbines. In a three phase power system the voltage for the CCN is taken from the same phase that connects to the black and white leads of the LDNs. The CCN draws approximately 0.12 A from the mains.


Figure 3.1 CCN Dimensional Information


Figure 3.2 CCN Connector Location Diagram


Figure 3.3 illustrates the connection of the power mains to the CCN controller. Note that there are a pair of L1 connections (formerly L) and a pair of L2 connections (formerly N). Each pair of terminals is internally connected on the PCB. The E terminal connects to the enclosure and may be connected to earth ground.

Remote Controlled Devices

In addition to directly controlling the dispensing turbine, several other devices may be controlled by the PLC-5000. These special applications will be discussed in detail in Section IV – Special Applications, but are briefly presented as an overview of the system’s capabilities.

Authorization Input Signals Variable speed turbines are designed to adjust their speed, and therefore the available volume of fuel, depending on the perceived demand. These devices are driven by a controller supplied with the turbine. Since the turbine is under the super-vision and control of its own controller, the LDN cannot assume direct control of the turbine. The channel outputs on the CCN are used to drive the inputs of the variable speed controller, signaling it to start and stop the turbine.

Authorization is the term for the signal that repre-sents a dispensing request. When the signal is active the channel is authorized to dispense fuel.

The authorization signal may be of any voltage from 60 to 230 volts AC or DC. The controller’s authorization input is open ended, that is, it is without a reference, so that signals from a variety of sources may be connected to the inputs. Figure 3.3 illustrates several circuit configurations. In all cases, the switch in the figure represents any control element which can provide the necessary signal. In most cases, an appropriate authorization signal can be found on the coil of an existing motor contactor.

In some applications it is desirable to have a sole-noid activated shut-off valve located in the distri-bution line. Even with the turbine running, this valve must be opened to allow the delivery of fuel. The channel output will control this solenoid valve.

If the turbine is powered through a TMS system, refer to Figure 2.8 for an illustration of how to create the authorization signal.

INSTALLATION

The CCN is packaged in an enclosure meeting the NEMA1 standard. It is not designed to operate in a classified hazardous environment. As indicated in the preceding discussion, the unit should be located in a manner so that it is both accessible by the operator and in the vicinity of the signals that must be connected to the controller.

Alarm Outputs

Two levels of alarms may be generated by the PLC-5000 Full Shut-down Controller. These are termed caution and service. A caution alarm rep-resents a warning that an error condition has been detected, but it is not of sufficient importance to shut-down the turbine. A service alarm represents an error condition of sufficient importance to warrant the shut-down of the turbine.

Following is a general outline of the installation procedure for the CCN. Some modification may be required to deal with issues presented by a specific application or site. It is the responsibility of the installer to provide an appropriate installa-tion which meets National Electrical Code and local code requirements.

These alarms are communicated in several ways. Active alarms are indicated on the display, while a record of past alarms may be presented on the display or printout. In addition, an audio alarm is initiated with the activation of any alarm. The audio alarm may be silenced using a push-button on the operator interface. The audio alarm will also be silenced by the clearing of the condition which triggered the alarm. Also, the audio alarm may be disabled through setup procedure. Refer to Section VI – System Operation for directions on how to disable the audio alarm.

1. Select a location for mounting the unit with attention to the availability of power mains and authorization signals.

TECHNICAL NOTE — In accordance with the NEC, the unit should be mounted at least three feet above the floor.

.


Figure 3.3 Power Mains and Authorization Signal Connections


2. The enclosure is provided with mounting holes which allow it to be secured to a wall or mounting board using screws. These holes are located at each inside corner of the enclosure.

5. Connect the power mains as illustrated in Figure 3.3 and Figures 2.1 and 2.2.

TECHNICAL NOTE — Power to the CCN should be provided through a circuit breaker independent of the fuel turbine breakers. If connected through a turbine breaker, turning off that particular product breaker will result in the shut-down of the entire dispensing system. If an independent breaker is not available, power may be obtained through an unrelated breaker sharing the appropriate power phase.

3. Four holes for 1/2” conduit connections are provided on the enclosure. In all cases, conduit attachments are restricted to areas within three inches of the enclosure’s bottom corners. This limitation is enforced to avoid internal components and to prevent damage caused by water dripping from conduits under humidity and temperature cycling. Plugs are provided to close unused holes. 6. Connect the authorization signals as illus-

trated in Figure 3.3. If the turbine is con-trolled through a TMS system, refer to Figure 2.9 for connection information.

4. Determine the sources for the power and authorization signals. If other signals need to be connected to the controller, determine their location. Develop a conduit system connecting to the enclosure that will properly convey these power and signal wires. Conform to electrical code requirements.

7. This completes the mechanical and electrical portions of the CCN installation procedure. Refer to Section V - Set-up Procedure to continue the installation process.


SECTION IV — SPECIAL APPLICATIONS

INTRODUCTION Other than these particular considerations, the installations of the CCN and LDNs are similar to that described for standard applications of the PLC-5000 Full Shit-down System.

Figure 1.1 illustrated the arrangement of equip-ment and nodes in a typical distribution network. This section presents information on special con-figurations of distribution systems which may be monitored and controlled by the PLC-5000 Full Shut-down System.

SOLENOID ACTUATED SHUT-OFF VALVE

An example of the use of a solenoid actuated shut-off valve can be found in marina applications. In this situation some of the distribution line is below ground, while the remainder is above ground, extending onto a wharf, dock or fueling platform. Figure 4.2 illustrates this concept. Note that the solenoid actuated shut-off valve is located at the point where the line transitions from below ground to above ground.

VARIABLE SPEED TURBINES

Variable speed turbines are designed to adjust their speed, and therefore the available volume of fuel, depending on the perceived demand. These types of devices are driven by a custom controller supplied with the turbine. This controller monitors the operating parameters of the turbine and produces a synthesized current supply which causes the turbine to rotate at the desired speed. As will be discussed in detail in a later section,

one of the functions of the PLC-5000 is to per-form precision leak testing on the distribution line. Because fuels are not ideal fluids they expand and contract under the influence of changing temperature. The fuel in the exposed pipe section is particularly affected by these changes. This makes it difficult to perform precision testing.

Because the turbine is under the supervision of its own controller, the LDN cannot assume direct control of the turbine. In addition, the presence of the variable speed controller prevents the LDN from using the turbine’s power mains as a com-munication medium. These two statements hold true for any monitoring and control equipment, regardless of manufacturer, which employs power line communication. Therefore, special consid-eration must be given to this application.

Working in our favor is the fact that exposed pipe can be visually inspected. Therefore, this section of the piping system is exempted from the rigors of automated precision testing. By locating the shut-off valve at the point where the pipe emerges from the ground, the line can be divided into two sections with only the underground section being monitored by the Full Shut-down System.

Figure 4.1 illustrates an installation incorporating variable speed turbines. Several points are worthy of note. First, note that the start/stop input on the variable speed controller is signaled by the output relay of the CCN.

Referring to Figure 4.2, there are two items of interest. First, the control element for the solenoid valve is the turbine output relay on the CCN. The figure shows a typical wiring scheme.

Second, the system type selected at installation must be the vs type indicating that the application is of the variable speed type. Refer to Section VI – System Operation for directions on type selection. Second, the system type selected at installation

must be the cv type indicating that the application is of the control valve type. In this application the operation of the turbine output relay is delayed until the line is determined to be tight. That is, the solenoid valve will not be opened until the line has been tested and determined to be tight. Also, during precision testing of the underground section of the line, the solenoid valve will not be opened. Refer to Section VI – System Operation for directions on type selection.

Third, since it is not possible to pass the power line communication signal through the variable speed controller, power for the LDN is not taken from the wires connected to the turbine, but rather from a separate pair of wires connecting directly to the power mains. This means that in retrofit situations an extra pair of wires will need to be pulled along with the additional wire probably needed to meet the three phase power require-ments of the variable speed turbine.


Figure 4.1 Variable Speed Turbine System


Figure 4.2 Solenoid Activated Shut-off Valve


1. The authorization signal is directed to the input of the first channel resulting in the activation of Turbine 1.

TECHNICAL NOTE — Fuels expand under increasing temperature. This means that the exposed section of pipe which is isolated by the shut-off valve may experience significant increases in line pressure. It is recommended that a one-way relief valve be positioned to shunt this pressure back into the underground portion of the line. The PLC-5000 incorporates features which enable it to divert this expanding fuel back into the storage tank. Using this technique, the exposed section of pipe will never experience excessive pressure which might damage fittings or couplings, or even the pipe itself.

2. When sufficient pressure has been developed in the line to pass the test protocol, the tur-bine output relay for channel 1 will activate generating the authorization signal for the second channel.

3. Turbine 2 will be activated by the CCN. Be-cause line pressure has already been estab-lished by Turbine 1, the pressure test per-formed by channel 2 will be immediately satisfied allowing the CCN to complete its leak test protocol.

4. The turbine output relay for channel 2 will activate. This output can be used in a similar manner to cascade an authorization signal to a third turbine, or the output can be used to drive another device such as a solenoid valve.

MULTI-TURBINE MANIFOLDS WITH STAGED TURBINE STARTING

Special consideration must be given to systems incorporating manifold piping driven by multiple turbines. Multiple turbines pressurizing the line at start-up puts a tremendous load on the power sup-ply and produces potentially damaging pressure profiles in the distribution system.

5. With the selector in the position 2, the circuit operation will be similar; however, it will begin with Turbine 2.

It is mandatory that activation of the turbines be sequenced. If both turbines are activated at the same time, the mechanical leak detectors will only be capable of detecting leaks of greater than 6 GPH. This is clearly outside of all monitoring requirements.

Figure 4.3 provides a schematic for sequential control of two turbines. A switch is provided to allow selection of the initial turbine. This is done to allow flexibility in operation and maintenance. Several points are worthy of note.

First, with the switch in position 1, Turbine 1 and LDN 1 are designated as the master devices, while Turbine 2 and LDN 2 are designated as the slave devices. With the switch in position 2, this order will be reversed.

Figure 4.4 illustrates a similar system incorporat-ing three turbines. Note the after the initial turbine has pressurized the line, additional turbines may be started in parallel.

Second, both turbines have check valve assem-blies installed. This is required to maintain line pressure when the turbines are off.

OPTION B MASTER-SLAVE SELECT

As noted above, the Control Valve (CV) and Staged Turbine (ST) control strategies provide for the sequencing of multiple turbines. Option B, which can be ordered with the CCN, provides pre-wired master-slave switching for staged turbine sequencing. It includes features which automatically disconnect the authorization signals on service alarm conditions. It also includes features which allow for the re-ordering of the staged sequence which facilitates maintenance and down time for tank leak and level monitoring. Contact VMI for additional information regarding this option.

Third, the system type selected at installation must be the st type indicating that the application is of the staged turbine type.

Fourth, the authorization signal passes through the normally closed contacts of a relay which is resident on the CCN’s control board. This relay is used to disable both turbines when an alarm con-dition is detected on either the master or slave channels.

With the selector in position 1 the operation proceeds as follows:


Figure 4.3 Manifolded Two-turbine System


Figure 4.4 Manifolded Three-turbine System


SECTION V — SET-UP PROCEDURE

INTRODUCTION

There are two phases to placing the PLC-5000 into service. The first is the physical installation of the mechanical and electrical elements of the system. The second is the establishment of the communication network. Both of these tasks are called by the term installation.

This section presents information enabling the installer to complete the second phase of the in-stallation process. Information regarding initial testing procedures is also presented. The informa-tion presented in this section assumes that the mechanical and electrical installation of the VMI Leak Detectors and the nodes of the PLC-5000 have been completed.

LONWORKS INSTALLATION PHILOSOPHY

In a LonWorks based system intelligent devices, the nodes, are connected to their physical com-munication medium, the power mains in this case, just as they would be in a conventional control system. However, unlike a conventional system where each node has a dedicated, hard-wired con-nection to the nodes with which it communicates, the nodes in a LonWorks based system all share the same communication medium.

Since the nodes share the same communication medium, physically attaching nodes to the net-work is not enough to allow the nodes to commu-nicate. The physical attachment only provides a path over which they send and receive messages; it does not tell the nodes with whom they should share data. The nodes in a control network need to be given network configuration information to enable them to understand the communication being sent on the network.

To facilitate this process, a procedure has been designed into the software of the nodes of the PLC-5000 System which greatly simplifies the processes of connecting the nodes in a specific network structure. This process is almost trans-parent to the installer.

INSTALLATION PROCEDURE

The final phase in the installation of remote nodes is accomplished using the Central Control Node.

The system’s software will facilitate installation, remember which nodes are installed and what addresses have been assigned, and allow for the replacement of nodes as necessary. No special installation tools or computers are required.

This final installation process requires the installer to use the push-button keypad and display located on the CCN. The following procedure assumes no operating knowledge of the CCN and therefore details each step of the final installation process.

For clarity, spaces are inserted in the example text, but there are no spaces in an actual entry. If a mistake is made during the data entry process, simply re-enter the complete data sequence.

1. Power On

Turn on the circuit breaker providing power to the CCN. After a few seconds the display will show a welcoming message referencing Vaporless Mfg and the revision level of the software installed in this node.

After several more seconds, the display will begin to present a series of message screens. This series of screens will continue to repeat as long as the CCN is active.

The first screen simply shows the date and time. This information may not be accurate and will be corrected later in this procedure.

The second screen indicates the current state of each of the remote LDNs. Since communi-cation has not been established with the LDNs, this screen will present a series of dashed lines.

The third screen will indicate the current alarm status of the system. At present, this screen will indicate No Alarms.

2. Setting the Date

Enter the following data sequence using the keypad. Verify that each entry appears on the display screen. Note that where a two digit response is required, both digits must appear even if the first digit is a zero.

CMD 91 mm dd yy ENTER

where mm = month, 01 - 12 dd = day, 01 - 31 yy = year, 00 - 99


5. Installing the Leak Detector Nodes The display will respond with the message Date Entered, and the date and time screen will display the new date. From this point, the LDNs will be referred to

by channel number. In general, each channel is associated with a product turbine and assigned a number 1 through 4.

3. Setting the Time

Enter the following data sequence: Determine which channel number has been

assigned to each of the LDNs. This process has already been done by virtue of the connection of the product authorization signals at the CCN. For example, the authorization signal for the product called unleaded regular may be connected to CCN authorization channel 1. By default the LDN controlling the turbine in the unleaded regular tank will be LDN 1.

CMD 92 hh mm ENTER

where hh = hours, 00 - 23 mm = minutes, 00 - 59

The display will respond with the message Time Entered, and the date and time screen will display the new time.

4. Select the System Type

The CCN is programmed to provide three types of operating sequences depending upon the particular requirements of the installation. The CCN was most likely programmed at the factory for the required configuration, but if necessary the type indicator may be selected at this time.

Turn on the circuit breaker providing power to the LDN which is to be installed. Proceed with the LDN installation process as detailed below.

Enter the following data sequence:

CMD 1 n ENTER Entering the following data sequence will

cause the printer to produce the configuration status report:

where n = 1 - 4 for the LDN channel.

For example entering CMD 1 1 ENTER will initiate the installation of LDN1.

CMD 71 ENTER Because this process will destroy any data

previously entered for this particular channel, the operator is prompted with the message:

The bottom four lines of the report will present the following information:

• Title of the report. ARE YOU SURE? 1 = Yes • Date and Time of report printing.

Using the keypad enter the number 1 indicat-ing a positive response. This means that you will continue with the installation process. Entering any other number or key will be interpreted as a negative response and result in the display of the message:

• Software version and type numbers. • Manufactures name.

The system type number is found as the last character of the third line from the bottom. The line reads as follows:

ERROR Cmd Aborted CENTRAL CONTROL NODE Vv.rt Having responded in the positive, the display

will provide the directive message: where v = the software version level r = the software revision level t = the system type number Press Service on LDN If the system type needs to be changed, enter

the following data sequence: The operator now has five minutes within

which to provide a response. The response is initiated by passing the magnet (supplied in the LDN installation kit) down the side of the LDN’s enclosure above the 3/4 NPT hole plug. If this action is not completed within the allotted time, the process will be aborted and the memory within the CCN will not be modified. Pushing any keypad button, except for numbers, will also abort the process.

CMD 97 t ENTER

where t = 1 for type cv, control valve t = 2 for type st, staged turbines t = 3 for type vs. variable speed

Additional information regarding the se-quence types may be found in the section on system operation.


Having activated the LDN’s service button, the display will respond with the message:

The following procedure assumes no knowledge of the operation of the LDT-890 Tester and there-fore details each step of the process. The opera-tion manual supplied with the LDT-890 provides additional information and should be consulted by the technician.

LDN n Installed

where the n will be replaced by the appropri-ate channel number.

6. Message Screens For clarity, spaces are inserted in the example text which is entered into the CCN. However, there are no spaces in an actual text entry. If a mistake is made during the data entry process, simply re-enter the complete data sequence.

As noted in Step 1, the CCN will display a series of messages on the display. As each LDN is installed the screens will reflect the current system status.

As before, the first screen shows the date and time. This information should be correct if the procedure was followed.

1. Power Off

Turn off the circuit breaker providing power to the product under test. This is done to prevent the starting of the turbine while the line is open in the following step. After about 15 seconds an audio alarm will be initiated in the CCN and the display will present the message:

The second screen will indicate the current status of each of the installed LDNs. For each installed LDN, where there previously were dashes, there will now appear an abbreviation which indicates the current state of the channel’s operating sequence. These state names will be discussed in the section on system operation.

LDN 0n SERVICE Comm Err Service where n = 1 - 4 for the LDN channel.

The third screen will indicate the current alarm status of the system. This screen should still be indicating No Alarms.

For example, if the circuit breaker associated with channel 1 was turned off, the message would read:

This completes the installation process for a single channel. Repeat Steps 5 and 6 until all required LDNs are installed.

LDN 01 SERVICE Comm Err Service

To silence the audio alarm, push the keypad button labeled BEEP RESET. This will silence the alarm, but the display will still show the service error message.

RESILIENCE CONSTANT MEASUREMENT

One of the features of the PLC-5000 System is its ability to perform standard and precision leak detection tests at levels of 3.0, 0.2 and 0.1 gph. Fundamental to the operation of the leak detection system it is known that a specific volume of fuel must leave the line for the pressure in the line to move from a specific higher pressure to a specific lower pressure. This volume is known as the resilience constant measured in milliliters. Since the volume is dependent on line characteristics, it must be measured for each line at a site.

2. Install LDT-890 Test Unit

Select the dispenser at the highest point of the delivery system. If there is no elevation difference, select the dispenser farthest from the turbine.

3. Carefully remove the plug from the test port on the dispenser’s impact valve. There may still be pressure in the line.

The following procedure is provided as a guide to determining the line’s resilience constant. This procedure assumes:

4. Install the 18” whip hose supplied with the 890 test unit. The application of thread seal-ing compound is recommended.

• The installation of the PLC-5000 Full Shutdown System.

5. Connect the quick disconnect coupler on the hose from the test unit to the whip hose.

• The installation of Vaporless Leak Detectors. 6. Set the test unit selector to the PRESSURE

STEP TEST position. • The use of the Vaporless Model LDT-890

Leak Detector Tester.


7. Power On 15. Initiate Precision Test

Turn on the circuit breaker. The service alarm message on the CCN display associated with this product channel will be canceled.

Enter the following data sequence for the channel under test.

CMD 42 n ENTER

where n = 1 - 4 for the LDN channel. 8. System Purge The display will respond with the message: Set the dispenser lever to the on position.

The turbine should start running. Watch for the turbine to achieve operating pressure as seen on the right-hand pressure gauge.

Channel n .2 Enabled For example, entering CMD 42 1 ENTER will

actually start a precision test at the 0.2 gph threshold for channel 1. The turbine for the selected channel will run briefly to pressurize the line and then the LDN’s shunt valve will operate to reduce the line pressure to a known value. These actions will be presented as state names on the display, but it is much easier to verify them by monitoring the right-hand pressure gauge on the LDT-890.

9. Check all connections for leaks. Correct any fault conditions.

10. With the large beaker (1000 ml) under the test unit’s discharge hose, set the test unit selector to the DISPENSER NOZZLE position. Purge the test unit of air by allowing 800 to 1000 ml of fuel to flow into the beaker. After purging the test unit, set the selector to the PRESSURE STEP TEST position.

16. Discover Test Actions 11. Purge the dispenser line by running 1 to 2

gallons of fuel into a collecting container. With reasonable haste, move to the test unit at the dispenser. Note the reading on the right hand pressure gauge. It may still be falling, but should soon stabilize.

12. Set the dispenser lever to the off position.

13. Message Screens 17. It is now the goal to discover the general per-

formance of the system in this mode. This is done as outlined in the following statements.

As noted under Installation Procedure earlier in this section, the CCN will display a series of three messages on the display.

18. With the large beaker (1000 ml) under the test unit’s discharge hose, turn the selector to the GPH TEST position. Fuel will begin to slowly flow into the beaker and the reading on the right hand gauge will begin to fall. If the rate of decrease is very slow, turning the selector more toward the DISPENSER NOZZLE position will increase the discharge rate and the rate of pressure loss.

The first screen shows the time and date.

The second screen will indicate the current state of each of the installed LDNs. These state names will change during the course of this procedure. The specific meaning of each state name will be discussed in the section on system operation.

The third screen will indicate the current alarm status of the system. This screen will probably be indicating No Alarms.

19. As the pressure falls it will reach the lower pressure threshold established by the LDN and the turbine will automatically be started. This will be obvious because the line pressure will rise rapidly. As quickly as possible return the selector to the PRESSURE STEP TEST position. It is best that the operator always be in control of the test unit’s selector.

14. Enter Initial Resilience Constant

Enter the following data sequence for the channel under test. Verify each entry in the display.

CMD 44 n 0100 ENTER 20. With the pressure again exceeding the upper

pressure threshold established by the LDN, the turbine will automatically be stopped. The shunt valve will open and the pressure will again fall to the stable value noted in Step 15. Each of these pressure changes can be monitored on the right-hand pressure gauge.


For example, entering CMD 44 1 0100 ENTER will set the resilience constant for channel 1 to 100 ml. This is necessary because a preci-sion test cannot be started with the resilience constant set at the default value of zero.


21. Repeat this series of operations several times until the operation of the system is understood in terms of pressure cycles. The volume of fuel discharged during each pressure cycle is actually the resilience constant. It is now the goal to specifically measure this volume.

Note that the resilience constant is entered as a four digit field. All four digits must be entered even if the first one or two digits are leading zeros.

The display will respond with the message:

Accepted 22. Measure Resilience Constant 25. End Test Depending on the characteristics of the

distribution line, this resilience constant can range from just a few milliliters to several hundred milliliters. If the volume is relatively small, the small beaker may be used for measuring the volume. If the volume is relatively large, the large beaker may be a better choice.

This successfully completes the measurement and entry of the resilience constant.

26. Disconnect LDT-890 Test Unit It is recommended that the installer continue

performance testing by completing the 3 GPH Leak Detection Protocol which immediately follows this procedure. However, if no further testing is to be performed on this channel, disconnect the LDT-890 from the impact valve using the following procedure.

With the selected beaker under the test unit’s discharge hose, again cycle the pressure while carefully collecting the discharged fuel. If the volume is very small, such as 5 to 10 ml, it may be appropriate to collect several samples in the beaker and then find the average volume by dividing the total volume by the number of samples. Read the volume on the scale printed on the side of the beaker. This test should be repeated several times to insure consistency.

27. Turn off the appropriate power breaker to prevent accidental starting of the turbine while the line is open during the following steps.

28. Turn the selector to the DISPENSER NOZZLE position and bleed off fuel until the reading on the right-hand pressure gauge is zero.

29. Disconnect the quick disconnect coupler attaching the test unit to the whip hose.

23. Manually Stop Precision Test

Enter the following data sequence for the channel under test. This sequence will stop the precision test that has been running dur-ing the measurement of the resilience constant.

30. Remove the whip hose from the test port and install the original plug. The application of thread sealing compound is recommended.

31. Full System Operation CMD 43 n ENTER Turn on the power breaker. This completes

the test procedure. The product is now under the control of the PLC-5000 System. Refer to the section of system operation for additional information regarding precision testing.


For example, entering CMD 43 1 ENTER will stop the precision test currently running on channel 1.

The display will respond with the message:

3 GPH LEAK DETECTION TEST Channel n

With the resilience constant programmed into the PLC-5000 Central Control Node and with the Vaporless LD-2000 or LD-3000 Leak Detectors installed, the system is capable of performing the leak detection test. The system should however be tested to confirm its operation and to prove compliance to regulating authorities.

Test Stopped

24. Enter Actual Resilience Constant

Enter the following data sequence for the channel under test. This sequence will enter the actual resilience constant into memory.

CMD 44 n vvvv ENTER The following procedure is provided to confirm leak detection operation and assumes use of the Vaporless Model LDT-890 Leak Detector Tester.

where n = 1 - 4 for the LDN channel, where vvvv = resilience constant.


8. System Purge The following procedure assumes no knowledge of the operation of the LDT-890 Tester and there-fore details each step of the process. The opera-tion manual supplied with the LDT-890 provides additional information and should be consulted by the technician.

Set the dispenser lever to the on position. The turbine should start running. Watch for the turbine to achieve operating pressure as seen on the right hand pressure gauge.

9. Check all connections for leaks. Correct any fault conditions. 1. Power Off

Turn off the circuit breaker providing power to the product under test. This is done to prevent the starting of the turbine while the line is open in the following step. After about 15 seconds an audio alarm will be initiated in the CCN and the display will present the message:

10. With the large beaker (1000 ml) under the test unit’s discharge hose, set the test unit selector to the DISPENSER NOZZLE position. Purge the test unit of air by allowing 800 to 1000 ml of fuel to flow into the beaker. After purging the test unit, set the selector to the PRESSURE STEP TEST position.

LDN 0n SERVICE 11. Purge the dispenser line by running 1 to 2 gallons of fuel into a collecting container. Comm Err Service

where n = 1 - 4 for the LDN channel. 12. Leak Calibration For example, if the turbine associated with

channel 1 was turned off, the message would read:

With the large beaker under the test unit’s discharge hose, set the test unit’s selector to the CALIBRATE GPH position. Fuel will begin to flow into the beaker. LDN 01 SERVICE

Comm Err Service 13. The object now is to calibrate flow from the test unit to the rate of 3 gph at 10 psi pressure at the discharge. This specification meets the requirements of the EPA regarding leak rate testing. This process may be tricky at first, but will become quite simple with experience.


2. Install LDT-890 Test Unit 14. The procedure is simply stated at follows:

Adjust the fuel flow using the left hand knob labeled CALIBRATE ORIFICE. Adjust the pressure on the left hand pressure gauge to 10 psi using the right hand knob labeled CALIBRATE PRESSURE.

Select the dispenser at the highest point of the delivery system. If there is no elevation difference, select the dispenser farthest from the turbine.

3. Carefully remove the plug from the test port on the impact valve. There may still be pressure in the line. Turn the ORIFICE knob counterclockwise to

increase flow and clockwise to decrease flow. 4. Install the 18” whip hose supplied with the

890 test unit. The application of thread seal-ing compound is recommended. Turn the PRESSURE knob counterclockwise to

reduce pressure and clockwise to increase pressure. 5. Connect the quick disconnect coupler on the

hose from the test unit to the whip hose. First adjust the flow using the ORIFICE knob and then adjust the gauge pressure using the PRESSURE knob. It is important to perform the procedure in this order.

6. Set the test unit selector to the PRESSURE STEP TEST position.

7. Power On 15. Using the small beaker (140 ml) collect a

sample of fuel over a 30 second interval. The flow is properly adjusted when 95 ml are collected in 30 seconds. This volume is

Turn on the circuit breaker. The service alarm message on the CCN display associated with this product channel will be canceled.


equivalent to a rate of 3 gallons per hour. Re-peat the procedure outlined in step 14 until the correct amount of fuel is collected.

an audio alarm will be initiated by the CCN and the display will present the message:

LDN 0n SERVICE 16. Set the test unit selector to the PRESSURE

STEP TEST position and set the dispenser lever to the off position.

3GPHFail Service


For example, if the test is being conducted on channel 1, the message would read:

20. 3 GPH Leak Test

Place the empty large beaker under the test unit’s discharge. Set the test unit selector to the GPH TEST position. Fuel will flow from the discharge and the pressure in the line will fall to zero.

LDN 01 SERVICE

3GPHFail Service


21. Set the dispenser lever to the on position. The turbine will start running and pressure will build in the line. The building pressure may be monitored using the right hand pressure gauge. Allow the pressure to build to a normal level. Note that with the selector in the GPH TEST position a 3 gph leak has been introduced to the system.

24. 3 GPH Leak Validation

The very fact that this procedure results in the initiation of an alarm condition is validation of the test capability.

24. Reestablishing Normal Operation 21. Start 3 GPH Test

Normal system operation for the affected channel is suspended while a service level alarm condition is present. To reestablish normal operation enter the following data se-quence using the keypad:

Set the dispenser lever to the off position. The turbine will stop running and the line pressure will begin to fall.

Setting the lever to the off position removed the authorization signal from the CCN. The response to this condition was to stop the tur-bine and to begin monitoring for a 3 gph leak.

CMD 62 n ENTER

where n = 1 – 4 for the LDN channel.

For example, entering CMD 62 1 ENTER will clear the service alarm present in channel 1. 22. 3 GPH Test Sequence

The line pressure will continue to fall due to the induced leak. When the pressure falls to approximately 12 psi, the CCN will start the turbine and reestablish normal pressure. When the line pressure has been reestab-lished, the turbine will again be turned off.

The display will respond with the message Channel 1 Service Cleared, and normal operation will be established.

25. Disconnect LDT-890 Test Unit

Disconnect the test unit using the procedure outlined in steps 24 - 28 of the section on Resilience Constant Measurement.

23. Leak Detection and Alarm

This cycling process will continue throughout the test sequence due to the fact that normal operating pressure cannot be maintained because of the induced 3 gph leak. After the pressure has cycled ten times

26. Full Channel Operation

Turn on the power breaker. This completes the test procedure. The product is now under the control of the PLC-5000 System.




SECTION VI — SYSTEM OPERATION

INTRODUCTION SYSTEM HARDWARE

The PLC-5000 Full Shut-down System is de-signed to monitor and detect leaks in closed pip-ing systems. Specifically, it is designed to meet Environmental Protection Agency (EPA) guide-lines for gasoline station monitoring.

The operator monitors and controls the system’s function using of the interface devices provided on the front panel of the Central Control Node (CCN). These devices include a display, a push-button keypad and a printer. Some CCNs may contain optional staged sequence selector switches and indicators. Following is a brief discussion of each of these devices. Details of use will be provided later in this section.

The system is an intelligent distributed control network composed of elements referred to as nodes. Each node is an electronic sub-system ca-pable of performing specific tasks. The remote nodes communicate with the central control node. The central control node functions as the master node in the network. The communication media in this network is the power mains. To restate this concept, all communication between nodes is car-ried on the same wires that provide power to the nodes of the network.

Display

The display is of the liquid crystal (LCD) type and is located near the top of the front panel. It is formatted as two rows with 24 characters per row.

The display is used for two purposes. In the nor-mal operation, a series of message screens will continue to repeat as long as the CCN is active. The first message screen shows the date and time. The next screen indicates the current state of each of the remote LDNs. The third screen indicates the alarm status of the system. The purpose of each of these message screens will be detailed as required in the following discussions.

The basic function of the Central Control Node (CCN) is to monitor for product dispensing re-quests, monitor the activity of each of the remote Leak Detector Nodes, and determine the operation of the submersible pumps or turbines. Also, in the event of a detected leak or other error condition, the CCN will issue appropriate alarms. While in the programming mode the display is

used to verify commands which the operator enters using the push-button keypad. Each of these commands will be detailed as required in the following discussions.

The basic function of the Leak Detector Node (LDN) is to monitor pressure in the distribution line and communicate the status of the line to the CCN. The LDN also directly controls its associ-ated pump or turbine under instruction from the CCN. In addition, the LDN is capable of monitor-ing an optional sump sensor for the presence of liquids. This sensor may be of the type which discriminates between water and hydrocarbons.

Located to the right of the display is a push-button which activates the display’s backlight feature. In a dark environment it is difficult to read an LCD type display. Therefore, backlighting is provided to enhance readability. The backlight will remain active as long as the push-button is activated. Mechanical leak detectors are also included in the

monitoring system. A leak detector is connected to an LDN so that both line pressure and the status of the leak detector can be monitored.

Push-Button Keypad

The keypad is located near the center of the front panel. The sixteen numeric and function keys are used by the operator to enter command instructions and to initiate specific operations relating to the CCN.

This section presents specific information re-garding the function and operation of the system using the facilities provided by the Central Control Node. Printer

The information presented in this section assumes that the mechanical and electrical installation of the VMI Leak Detectors and the nodes of the PLC-5000 have been completed.

The printer is located near the bottom of the front panel. It is used to produce a variety of reports which detail the configuration and status of the system.


2. Use the PAPER FEED push-button located at the lower right corner of the keypad to advance the paper so that about two inches of paper extends from the mechanism. Each time the button is pushed the paper will advance three lines. Push the button several times to advance the paper as required.

The 24-column printer mechanism is of the im-pact dot matrix type. It requires the replacement of both paper and printing ribbon as needed. Fol-lowing is the procedure for changing the paper and ribbon.

Changing Printer Paper

The printer uses a paper roll that measures 2-1/4” wide by 1.6” (1-5/8”) in outside diameter. 3. Press on the left end of the ribbon cartridge on

the area labeled PUSH to unlatch the cartridge from the printer. Refer to Figure 6.1 for illustrations of the paper

changing procedure. It is not necessary to open the front panel of the CCN to change the paper roll.

4. Lift both ends of the cartridge to remove it from the printer.

5. Turn the knob on the right end of the new car-tridge as needed to ensure that the ribbon is tight.

1. Slide the front cover of the printer down about one-half inch and lift it off of the base.

2. Pull the left end of the paper spindle from its latch and remove the spindle and old paper core. If any paper is remaining on the core, simply pull it back through the printer as the spindle and core are removed.

6. Feed the extended paper through the slot formed by the ribbon and the cartridge. Slide the cartridge into the printer snapping it firmly into place.

7. Feed the loose end of the paper through the slot on the cover and position the cover on the printer with about a one-half inch gap between the top of the cover and the top of the printer. Slide the cover up until its latches in its final position.

3. While holding a new roll of paper with the end of the paper sticking up from the back of the roll, insert the end of the paper into the paper slot of the printer mechanism. Use the PAPER FEED push-button located at the lower right corner of the keypad to advance the paper through the mechanism. Each time the button is pushed the paper will advance three lines. Push the button several times to advance the paper completely through the mechanism until about two inches of paper extends from the mechanism.

TURBINE SEQUENCE CONTROL

The PLC-5000 Full Shut-down System is capable of controlling a variety of distribution configura-tions. Most of these configurations would fall into the normal category, while others would be con-sidered as special applications. The following discussion provides information regarding the sequence of events in both normal and special applications. These sequences will also be referenced in the discussion of command codes later in this section.

4. Insert the right end of the spindle into the core.

5. Insert the right end of the spindle into its holder.

6. Snap the left end of the spindle into its latch.

7. Feed the loose end of the paper through the slot on the cover and position the cover on the printer with about a one-half inch gap between the top of the cover and the top of the printer. Slide the cover up until it latches in its final position.

Basic Operating Sequence

The following statements outline the basic opera-tion of the shut-down system.

1. With power applied, the system is active and will monitor for dispensing requests and alarm conditions. The display will present a series of messages. These messages will continue to repeat as long as the CCN is active and in the normal mode of operation.

Changing the Ribbon Cartridge

The printer uses an Epson ERC-09 (or equivalent) ribbon cassette. It is not necessary to open the front panel of the CCN to change the ribbon cartridge.

1. Slide the front cover of the printer down about one-half inch and lift it off of the base.

The first of the message screens shows the date and time.


Figure 6.1 Changing Paper Roll and Ribbon Cartridge


The next screen indicates the current state of each of the installed channels. A listing of the states is presented in this section.

Control Valve (CV) Sequence

Following receipt of an authorization signal, the CCN will issue a command to the LDN energizing its turbine contactor. When an appropriate line pressure has been achieved, the channel output relay in the CCN is activated. The contacts of this relay can be used to operate a control valve at the point where a distribution line transitions from a buried line to an exposed line. This output could also be used to implement staged starting of two or more turbines.

The third screen indicates the current alarm status of the system. Obviously, it is the goal to have no active alarms. A listing of the possible alarms is presented in this section.

2. The following statements apply to each install LDN channel. That is, the operating sequence applies individually to each installed channel. Each channel may be in a different state and/or alarm condition. Staged Turbine (ST) Sequence

Following receipt of an authorization signal, the CCN will issue a command to the LDN energiz-ing its turbine contactor. When an appropriate line pressure has been achieved, the channel will advance to the dispensing state. While in this state fuel may be delivered, but the output relay in the CCN remains inactive. When the line pressure falls below a fixed threshold, the output relay in the CCN is activated. The contacts of this relay can be used to produce an authorization signal for another channel. Using this sequencing technique, the controller can implement an on-demand staged sequencing of two or more turbines.

3. Upon receiving an authorization signal for fuel dispensing, the CCN will issue a command to the appropriate LDN to energize its turbine.

4. When the LDN determines that proper line pressure has been achieved, it will communi-cate this status to the CCN. This particular line will have passed a basic performance test and the CCN will then allow continued dispensing of fuel.

5. If proper line pressure is not achieved within the required time, a pressure failure condition exists. Under this condition the CCN will signal the LDN to deenergize its turbine contactor and an appropriate alarm will be issued. This action represents one of the full shut-down modes of the system.

Variable Speed (VS) Sequence

Variable speed turbines are designed to adjust their speed, and therefore the available volume of fuel, depending on the perceived demand. These types of devices are driven by a custom controller supplied with the turbine. This controller monitors the operating parameters of the turbine and produces a synthesized current supply which causes the turbine to rotate at the desired speed.

6. In addition to the leak detection procedure outlined in paragraphs 4 and 5 above, the CCN will also perform a 3 gph leak test following completion of any dispensing sequence.

7. When requested, the CCN will also conduct precision leak testing at levels of 0.1 gph and 0.2 gph.

Because the turbine is under the supervision and control of its own controller, the LDN cannot as-sume direct control of the turbine. In addition, the presence of the variable speed controller prevents the LDN from using the turbine’s power mains as a communication medium. These two statements hold true for any monitoring and control equip-ment, regardless of manufacturer, which employs power line communication. Therefore, special consideration must be given to this application. (Refer to Section IV-Special Applications.)

Variations of Turbine Sequence Control

In addition to controlling the turbine contactor located in the LDN, the CCN also controls a channel output relay. This relay and its terminal block are located in the lower left corner of the CCN’s circuit board (refer to Figure 3.2). Under software control, the relay is energized independ-ent of the turbine contactor. Three protocols in-volving the sequence control of the contactor and relay are defined. These sequences will be refer-enced in the discussion of command codes later in this section. The following discussions provide details regarding these sequences. Also refer to Section IV for discussion of special applications.

As noted above, the LDN does not exercise direct control of the turbine. In this configuration, the turbine is controlled by a custom controller sup-plied with the turbine. Following receipt of an authorization signal, the CCN tries to issue a tur-bine control command to the LDN, but is unsuc-


cessful. However, the channel output relay in the CCN is immediately activated. The contacts of this relay are used to signal the start/stop input of the turbine controller. Line pressure monitoring is still performed by the LDN, and all testing and alarm functions are maintained.

Wait WAIT

This is the normal stand-by state for a channel. While in this state, the channel is monitoring for an authorization signal, alarm conditions, a re-quest to begin a precision line leak test, for the need to reduce line pressure caused by thermal expansion, and for the need to repressurize the line if the channel is used infrequently

Option B Master-Slave Select

As noted above, the Control Valve (CV) and Staged Turbine (ST) control strategies provide for the sequencing of multiple turbines. Option B, which can be ordered with the CCN, provides pre-wired master-slave switching for staged turbine sequencing. It includes features which automatically disconnect the authorization signals on service alarm conditions. It also includes features which allow for the re-ordering of the staged sequence which facilitates maintenance and down time for tank leak and level monitoring. Contact VMI for additional information regarding this option.

Monitor MONIT

An authorization signal has been received, the turbine has been started, and the CCN is moni-toring for appropriate line pressure. If the channel remains in this state for more test time, an alarm condition exists. (Refer to the list of alarm definitions for details.)

Dispensing DISP

Appropriate line pressure has been achieved and the continued dispensing of fuel is allowed. While in this state, if the sequence type is defined as staged turbine (ST) and if pressure falls to a fixed threshold, the channel output relay is energized.

CCN STATE LIST Valve VALVE The application software for the control system is

implemented in a form referred to as a state ma-chine. Simply put, a control node is allowed to be in only one state at any particular time. While in a state it can perform only the functions defined for that state. In addition, in order to move from any state to another state, certain conditions must be meet. Of course, these conditions change de-pending upon the particular state.

Following dispensing, the pressure in the line is reduced by the opening of the shunt valve. This is done to prevent line damage due to excessive pressure. Also, this state is called from the WAIT state, if pressure builds due to thermal expansion.

Repressure REPRS

The PLC-5000 provides for automatic line repres-surization if the channel is used infrequently. This state calculates the delay to the next repressure sequence.

As discussed earlier in this section, the display is used to present a series of message screens. The second of these screens presents the current state information for each installed channel in the con-trol system. Following is a list of the states de-fined for the Central Control Node. The abbrevi-ated state name will appear in the display screen as required.

Alarm ALARM

Indicates that the channel has an active alarm. Alarms may also be present while the channel is in the WAIT state.

Look_A LOOKA Initialize INIT This is the state which conducts a 3 gph line leak

test following the completion of a dispensing op-eration.

When power is first applied to the system, an initialization procedure is performed. This state name will never appear in the display, but is replaced by a welcoming message. Pressure_0 PRES0

Line pressure is re-established during any of the line leak testing protocols. -----

The series of dashes indicated that the LDN for this particular channel is not installed. No control, monitoring, testing or alarm indications will be provided for this channel.

Drop_0 DROP0

Line pressure is dropped to a fixed threshold during any of the line leak testing protocols.


Precision Test States

Following is a listing of the states which may be entered while in the 0.1 gph or 0.2 gph precision test protocols. Details of the function of these states are not provided. Pressure_0 PRES0 Drop_0 DROP0 Look_0 LOOK0 Pressure_1 PRES1 Drop_1 DROP1 Look_1 LOOK1 Pressure_2 PRES2 Drop_2 DROP2 Look_2 LOOK2 Pressure_3 PRES3 Drop_3 DROP3 Look_3 LOOK3

CCN ALARM LIST

A variety of alarm conditions can be detected, time/date stamped, logged, presented on the display and archived on the printer. Three categories of alarms actions are defined.

The caution alarm notifies of irregular system operation. This alarm is indicated by the audio tone (if the beeper is enabled) and a message in the display’s alarm screen. No special actions are required to continue dispensing operations.

The service alarm notifies of serious deviation in system operation and results in the full shut-down of the channel and the prevention of dispensing operations. This alarm is indicated by the audio tone (if the beeper is enabled) and a message in the display’s alarm screen. The condition causing the alarm must be cleared before dispensing op-eration can continue.

The report alarm notifies of completion and status of a test or action. This alarm is only recorded in the appropriate report log and may be viewed on a printout of such report. No special actions are required to continue dispensing operations.

All alarms associated with associated with system operation will be time/date stamped and recorded in the Alarm Log. This log may be cleared by command code 61. (Refer to Command Codes in this section.) Up to 99 alarms may be accumulated in this log. The oldest alarm will be dropped if more than 99 alarms are accumulated.

All alarms and test results associated with precision tests will be time/date stamped and

recorded in the Precision Test Log. This log cannot be cleared by command code. Up to 30 alarms and test results may be accumulated in this log. The oldest information will be dropped if more than entries are accumulated.

Following is a list of alarm conditions.

Communication Alarm Service Level

The LDN communicates with the CCN whenever a change in its state is detected. The LDN also communicates its status to the CCN approxi-mately every five seconds regardless of whether a change in state has been detected. If the CCN fails to detect LDN communication for a period of 15 seconds a communication alarm is initiated. This is a service level alarm.

Time-out Alarm Caution Level Following the receipt of an authorization signal and the starting of the turbine, the LDN is unable to detect the required pressure in the distribution line. This results in the shut-down of the turbine and the issuing of a caution alarm. Subsequent dispensing operations are allowed.

Sump Low Level Caution Level The low level switch of the optional sump sensor has been activated.

Sump High/Gas Level Service Level The high level switch or the hydrocarbon element of the optional sump sensor has been activated. This results in the shut-down of the turbine and the prevention of dispensing operations.

Sump Sensor Disconnect Service Level An optional sump sensor which has been a part of the control system has been disconnected. This results in the shut-down of the turbine and the prevention of dispensing operations until the sen-sor has been reconnected.

Sump Sensor Connect Report Level An optional sump sensor which had been discon-nected has now been reconnected. This action is recorded in the alarm log and is available on the alarm log printout.

3GPH Leak Detection Service Level A 3 gph leak has been detected following com-pletion of a dispensing operation. This service level alarm will prevent subsequent dispensing operations. A command code is used to clear this alarm.


Precision Test 30 Limit Service Level

During the initial phase of a 0.1 gph or 0.2 gph precision test protocol, thirty consecutive tests with results greater than 1 gph have been detected. This leads to the conclusion is that there is either a major leak in the line which is greater than 1 gph and smaller than 3 gph, or that the line is undergoing significant thermal expansion which does not seem to be resolving.

Precision Test Manual Stop Report Level

A currently active precision test has been manu-ally stopped by the operator.

Precision Test No Pressure Report Level

A currently active precision test has been stopped due to the inability of the system to repressurize the distribution line.

Precision Test Comm Error Report Level

A currently active precision test has been aborted due to a communication failure with the LDN.

Precision Test Service Alarm Report Level

A currently active precision test has been aborted due to the assertion of a service level alarm by some other facility of the control system.

COMMAND CODES

Three part command sequences are used to con-figure and control the PLC-5000 Full Shut-down System. The command sequences are entered us-ing the push-button keypad and presented for verification on the display.

A command sequence is initiated by pressing the CMD button on the keypad. The normal cycling of the message screens on the display will be terminated and the characters CMD will be presented in the upper left of the display.

The second part of the command sequence includes a series of numbers which may identify a channel and/or an action to be taken. These numbers will be inserted in the display following the CMD character.

The command sequence is executed by pressing the ENTER button on the keypad. Normal cycling of the message screens will resume following execution of the command.

Following is a listing and description of the available command codes. For clarity, spaces are

inserted in the example text, but there are no spaces in an actual entry. If a mistake is made during the data entry process, simply re-enter the complete data sequence. A sequence may be terminated at any time using the ENTER button. If the command is incomplete or incorrect, an error message will be displayed. Simply re-enter the correct data sequence terminating with the ENTER button.

The codes are divided into groups which represent several basic operation categories, such as, the printer group and the display group. The operator will soon become familiar with the system facilities and be able to find a required command code with ease. The listing of command codes is provided in numeric sequence.

For convenience, a laminated card containing a summary of the command codes is provided with this manual. The card may be retained with the manual or placed inside of the CCN’s enclosure.

INSTALLATION GROUP

Install Leak Detector Node

1n where n = 1-4 (channels 1-4)

This command is used to install an LDN. Refer to Section V – Set-up Procedure, Installation Procedure for detailed instructions on use of this command.

PRECISION TEST GROUP

Start 0.1 gph Precision Leak Test


If the specified channel is defined as a lead chan-nel, entering this command will signal the con-troller to begin a 0.1 gph precision leak test when next the channel enters the WAIT state. A message indicating acceptance will be displayed.

If the specified channel is not defined as a lead channel, entering this command will result in the display of an error message and the command will not be executed.

Start 0.2 gph Precision Leak Test


If the specified channel is defined as a lead channel, entering this command will signal the controller to begin a 0.2 gph precision leak test


when next the channel enters the WAIT state. A message indicating acceptance will be displayed.

report will contain up to 99 entries accumulated since the last time the log was cleared. Refer to Printout Formats later in this section. If the specified channel is not defined as a lead

channel, entering this command will result in the display of an error message and the command will not be executed.

Printer Paper Feed

Pushing the PAPER FEED button on the keypad will cause the paper to advance approximately three lines. Stop Precision Leak Test

43n where n = 1-4 (channels 1-4) Print Configuration Status If a precision leak test is active in the specified channel, the test will be stopped. A Precision Test Manual Stop alarm message will placed in the test log and a message indication the termination of the test will be displayed.

71

This command is used to initiate the printing of the System Configuration Status report. Refer to Printout Formats later in this section.

Print Precision Test Log If a precision leak test is not active on the specified channel, this command will result in an error message stating that a test is not running.

72

This command is used to initiate the printing of the Precision Test Log. This report will contain up to 30 entries. Refer to Printout Formats later in this section.

Enter Line Resilience Constant 44ncccc where n = 1-4 (channels 1-4) where cccc = resilience value, 0001-9999 This command is used to enter the line resilience constant associated with the specified channel. Refer to Section V – Set-up Procedure, Resilience Constant Measurement for detailed instructions on the use of this command.

DISPLAY GROUP

Display Alarm Log

Pushing the DISP ALARM button on the keypad will initiate the display of the Alarm Log. Subsequent operation of the DISP ALARM button will advance the log through the display.

ALARM GROUP Reset Alarm Beeper

Display System Configuration Pushing the BEEP RESET button on the keypad will silence the audio beeper. 81 Clear Alarm Log This command is used to initiate the display of

configuration status information. Only the group address, beeper status and identification of the installed nodes will be presented. To produce a printout additional status information, refer to command code 71.

61

This command is used to clear all entries in the alarm log. Refer to Printing of Log Reports presented later in this section.

Clear LDN Service Alarm Display Current LDN Status 62n where n = 1-4 (channels 1-4) 82n where n = 1-4 (channels 1-4) As indicated under CCN Alarm List, certain ser-vice level alarms can be cleared using this com-mand code.

This command is used to display the status of the selected LDN.

Display Precision Test Log

84 PRINTER GROUP

This command is used to initiate the display of the Precision Test Log. Subsequent operation of the DISP ALARM button will advance the log through the display.

Print Alarm Log

Pushing the PRINT ALARM button on the keypad will initiate the printing of the Alarm Log. This


MISCELLANEOUS GROUP

Set Date

91mmddyy where mm = month, 01-12 where dd = day, 01-31 where yy = year, 00-99

This command is used to enter the date. Refer to Section V-Set-Up Procedure, Installation Proce-dure for detailed instructions on the use of this command.

Set Time

92hhmm where hh = hours, 00-23 where mm = minutes, 00-59

This command is used to enter the time. Refer to Section V-Set-Up Procedure, Installation Proce-dure for detailed instructions on the use of this command.

Enable / Disable Beeper

93n where n = 0, disable beeper where n = 1, enable beeper

This command is used to enable or disable the alarm beeper as indicated above.

Set System Group Address

94n where n = 0-9

Because the PLC-5000 Full Shut-Down System uses the power line as the communication media, and because this communication is affective over thousands of feet, a method was devised to pre-vent systems in close proximity from interfering with each other. A group address assigned to the system is imbedded in each packet of information transmitted on the network. Ten group addresses are defined as the numbers zero through nine.

Group address 0 is the factory default. The group address may be changed using this command code. However, if the group address is changed, all peripheral nodes must be reinstalled.

Set / Clear Low Pressure Flag

95nf where n = 1-4 (channels 1-4) where f = 0, clear low pressure flag where f = 1, set low pressure flag

The PLC-5000 Full Shut-Down System monitors pressure to determine the integrity of the distribu-tion lines. The turbine must develop approxi-mately 26 psi in order for the controller to allow the dispensing of fuel. In some installations the turbine is unable to deliver this level of perform-

ance. While there are technical reasons to requir-ing this level of pressure, provision has been made to allow dispensing of fuel and the testing of the lines to take place at a pressure as low as 18 psi. This command is used to select the low pressure mode of operation.

Clearing the flag to zero places the controller in the high pressure mode. This is the desirable con-dition. Setting the flag to one places the controller in the low pressure mode. While product can be delivered in the mode, the system is technically not as robust as the high pressure mode.

Enter Station Identification Number

96nnnnnn where nnnnnn = identification number

An identification number may be assigned to the site. This number contains six numeric characters. This number will appear on all printed reports.

Enter Sequence Type Indicator

97t where t = 1 for type cv, control valve where t = 2 for type st, staged turbines where t = 3 for type vs, variable speed

Refer to Turbine Sequence Control earlier in this section for definitions of sequence types. If a spe-cific sequence type is not required in the applica-tion, any type may be specified. Sequence type 1 is the factory default.

LEAK TESTING PROTOCOLS

In addition to controlling turbines during fuel dispensing operations, the PLC-5000 Full Shut-Down System monitors for line leaks at three distinct threshold levels.

Following each dispensing operation, the CCN initiates a 3 gph test. This test is designed to detect the presence of very large leaks.

In addition to testing under software control, the presence of VMI mechanical leak detectors pro-vides continuous monitoring of the distribution system for leaks at the 3 gph threshold.

The VMI family electronic systems and mechani-cal leak detectors will meet or exceed to EPA requirements for line leak detection.

Under software control the system is also capable of testing for leaks at the 0.1 gph and 0.2 gph threshold levels. It is the responsibility of the operator to initiate these tests as required to meet EPA protocols.


PRINTOUT FORMATS

A previously discussed in this section, three types of reports may be generated by the printer. These reports are:

Configuration / Status Report Alarm Log Report Precision Test Report.

Figure 6.2 illustrates the format of the Configura-tion / Status Report.

Figure 6.3 illustrates the format of the Alarm Log Report.

Figure 6.4 illustrates the format of the Precision Test Report.


Figure 6.2 Configuration / Status Report Format


Figure 6.3 Alarm Log Report Format


Figure 6.4 Precision Test Log Report Format




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