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1
INSTRUCTION MANUALFOR
PFC14 / PFC8POWER FACTOR
CONTROLLER
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CONTENTS
SECTION I Introduction .................... 2
SECTION II Installation .................... 32.1 Preliminary Check2.2 Configuration Settings2.3 Mounting & Wiring
SECTION III Operation ............... 163.1 Operation3.2 Maintenance
SECTION IV Specifications ...... 214.1 Panel cutout drawing
SECTION V Wiring diagram ..... 24
ANNEXURE 1 C/K TABLE ..….. 25
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SECTION I
INTRODUCTION
Power Factor Controller Relay {Model PFC 14 & PFC 8} is designed for automatic control of capacitor banks to maintain system power factor under varying load conditions. It employs state-of- the-art microprocessor techniques for measurement of reactive current, system power factor and ensures hunt free operation. It can control up to 14 (8)* capacitor banks. The parameters such as number of capacitor banks, switching program, switching delay are user selectable. It also displays system power factor continuously and indicates whether it is lagging or leading with respect to set power factor.
PFCR {Power Factor Controller Relay} protects the capacitor banks whenever power interruption occurs by switching ‘OFF’ all capacitor banks and providing a safety lockout period of minimum 60 sec. It also offers
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over voltage protection by disconnecting all capacitor banks in case of over voltage conditions.
* Text written in parentheses corresponds to PFC 8 throughout this manual.
# For PFC 14 no. of selectable capacitor banks are 4 to 14.# For PFC 8 no. of selectable capacitor banks are 4 to 8.
SECTION II
INSTALLATION
2.1 Preliminary Check
The relay packing consists of:
1. PFC Relay2. Mounting clamps3. Instruction Manual4. Test certificate
Check the PFCR for any obvious damage, if found
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inform nearest L&T office or dealer.
Follow the instructions below for basic functional check:
a) Remove protective cover from the terminal block by removing four screws and connect 415V AC supply between terminals 22 & 23.
b) Switch ‘ON’ the supply voltage. All LEDs on the front panel will flash twice and two digit seven segment display will keep toggling between number ‘1’ and ‘3’. Whenever number ‘1’ is displayed, a green LED marked ‘OK’ or ‘Lead’ or ‘Lag’ will glow and a red LED marked ‘ALARM-CODE’ will glow when number ‘3’ is displayed.
A yellow LED marked ‘AUTO’ will glow continuously. This indicates that PFCR is in AUTO mode. All other LEDs will remain ‘OFF’.Whenever SET COSφ or SET C/K push buttons are referred then the relay is to be in AUTO mode. Whenever CAP+ or CAP- push buttons are referred,
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relay is to be in MANUAL mode. This convention is followed throughout this manual.
c) Press the button SET COSφ and turn the potentiometer ‘COSφ‘ by keeping the button SET COSφ in pressed condition. Observe that the display indicates 80 when potentiometer is in extreme counter clockwise position. Slowly turn the potentiometer clockwise, the display will go on increasing upto 99 and then show 1. Further turning of potentiometer in same direction will result in display indicating again 99 and it will go on decreasing to show 95 in extreme clockwise condition. Release SET COSφ button, display should start toggling between number ‘1’ and ‘3’ as before.
d) Now turn potentiometer ‘C/K’ by keeping the button SET C/K in pressed condition. Observe that display changes from 05 to 1 as the potentiometer is moved from extreme counter clockwise position to extreme clockwise position. Release SET C/K button, display should start toggling between number ‘1’ and ‘3’.
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e) Press the middle button, LED marked ‘AUTO’ will go ‘OFF’ and a red LED marked ‘MANUAL’ will switch ‘ON’ indicating that PFCR is now in MANUAL mode. In this mode keep the button marked CAP+ in pressed condition continuously. Observe that after about 70 sec. {after safety lockout time} first relay operates. This is indicated by a green LED marked 1. Keep the switch CAP+ in pressed condition. After about 3 sec green LED marked 2 will glow indicating that second relay has operated. If CAP+ switch continues to be in operated condition, one by one all 14 (8) relays will switch ‘ON’ {If no. of bank selected is 14 (8). Ref. section 2.2.3 for setting } and all 14 (8) green LEDs will start glowing. Operating button marked CAP- will switch ‘OFF’ the relays one by one starting from first relay.
This completes the functional check of PFCR. Switch ‘OFF’ the relays by disconnecting the supply.
2.2 Configuration Settings
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User can set five different parameters while installing the PFCR, they are: Setting the:-- Desired Power factor {COSφ}.- C / K value.- No. of capacitor banks in PFC 14 {4 to 14}, PFC 8 (4 to 8).- Capacitor bank configuration.- Capacitor Bank switching delay.
2.2.1 Setting The Power Factor { cos φ }
The desired power factor can be set as follows :
Select AUTO mode.
Press the button marked SET COSφ. Display will show the set power factor.
Rotate the potentiometer ‘COSφ‘ keeping the button SET COSφ pressed to get the display of desired power factor.
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2.2.2 Setting The C/K Value
C/K value is the measure of Threshold Reactive Current. It is a ratio of minimum capacitor bank size and CT ratio as given below:
PcC/K = 0.66 ---------------------------
V * √(3) * CT RATIO
Where ,Pc = Minimum capacitor bank size {kVAR},V = Supply Voltage {415 V},CT RATIO = Ratio of current transformer used
for feeding current to PFCR.
Eg. If CT used is 1000:5A, then CT RATIO is 200.
The C/K setting can be done in two ways; manually or automatic.
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2.2.2.a Manual Setting Of C/K
Calculate the value of C/K using the above formula or get C/K value using C/K TABLE {ANNEXURE 1}.
Select AUTO mode.
Press the button marked SET C/K. Display will show the SET C/K value.
Rotate the potentiometer ‘C/K’ keeping the button SET C/K pressed to get the display of desired C/K value.
2.2.2.b Automatic C/K Setting
In this mode PFCR actually measures the capacity of the bank and adjusts the C/K value. Hence it is more accurate than manual setting. Follow these instructions below for automatic C/K setting.
Disconnect the load.
Connect only the least capacitor bank to relay 1 {R1, Terminal No.1}, if Capacitor bank configuration is
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1:1:1:1. If not connect least capacitor bank to R14 i.e., terminal No. 15 for PFC 14 (or R8 i.e., terminal No. 8 for PFC 8). Switch ‘ON’ the input voltage to PFCR by keeping SET COS φ and SET C/K buttons pressed. Display will indicate number ‘8’ and Code LED will glow indicating that Auto C/K mode has been selected.
Enter the CT RATIO in four digits as follows:
a) Select MANUAL mode by pressing Auto/Manual button. LED marked ‘Lead’ will glow indicating that user can enter most significant two digits of CT RATIO using ‘C/K’ potentiometer.
b) Rotate ‘C/K’ potentiometer till display shows two most significant digits of the CT RATIO.{e.g.: For a CT of 1000:5, ratio is 200 and CT RATIO code to be entered is 0200. Adjust C/K control till display shows 02}.
c) Press CAP- button. PFCR will accept two most significant digits of CT RATIO and LED marked
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‘Lag’ will start glowing indicating that user can enter least significant two digits of CT RATIO.
d) Rotate ‘COS φ‘ potentiometer till display indicates required value {In above example it is 00}.
e) Press CAP+ button. PFCR will accept least significant two digits. This completes the entering of CT RATIO code.
f) Return to AUTO mode by pressing AUTO / MANUAL button. PFCR will switch ‘ON’ the least valued capacitor. Rotate ‘C/K’ potentiometer till LED marked ‘OK’ glows.
This completes the setting procedure. Press SET COSφ and SET C/K buttons together, PFCR will return to normal mode of operation.
NOTE : DIP Switch
8 Way DIP switch is located at the right hand bottom corner of the front panel as shown in FIG 1. By this
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DIP switch it is possible to select no. of capacitor banks, testing of relays, capacitor bank configuration & capacitor bank switching delay.
The DIP switch should be selected when unit is in ‘OFF’ condition. Change in Dip switch position when PFCR is ‘ON’ will not come into effect except switch no. 3 by which PFCR will come out of relay test mode.
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2.2.3 Selection of Number Of Capacitor Banks
Set the positions of DIP switch number 6, 7 and 8 as indicated in the TABLE-1 & FIG 2.a & FIG 2.b to get the required number of capacitor banks.
NO. OF BANKS
S/W 6
S/W 7
S/W 8
4 OFF OFF OFF 5 OFF OFF ON 6 OFF ON OFF 7 OFF ON ON 8 ON OFF OFF* 10 ON OFF ON* 12 ON ON OFF* 14 ON ON ON
TABLE 1: Selection of no. of capacitor banks.
* These options are not available in PFC 8.
CAUTION: IF SWITCH NO. 3 IS KEPT IN ‘ON’ POSITION, PFCR GOES IN RELAY TEST MODE. {REFER SECTION 3.1.2.a FOR DETAILS} ENSURE THAT SWITCH NO. 3 IS IN ‘OFF’ POSITION FOR NORMAL OPERATION.
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2.2.4 Selection of Capacitor Bank Configuration:Positions of DIP switch number 1 and 2 should be set as indicated in TABLE-2 & FIG 2.a & FIG 2.b to match the capacitor bank configuration available.
Cap. Bank Configuration
S/W 1
S/W 2
1:1:1:1:1:...:1 OFF OFF 1:2:2:2:2:...:2 ON OFF 1:2:4:4:4:...:4 OFF ON 1:2:4:8:8:...:8 ON ONTABLE 2: Capacitor bank configuration.
2.2.5 Selection of switching DelaySet the position of DIPswitch number 4 and 5 as indicated in TABLE-3 & FIG 2.a & FIG 2.b to get the required delay.
Switching Delay
S/W 4
S/W 5
10 Sec. OFF OFF 20 Sec. OFF ON 40 Sec. ON OFF 60 Sec. ON ON
TABLE 3: Switching delay selection.
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After setting the required configuration fix the cover strip back with the help of two screws.
2.3 Mounting And Wiring
PFCR is designed for flush mounting on the panel. Refer. Section IV {FIG 3} for panel cutout dimensions and space required behind the panel. Fix the mounting clamps supplied along with, to both the sides of the relay. Insert the relay through the panel cutout and hold it firmly against the panel, tighten the screws on the mounting bracket.
Wire the relay terminals as shown in the wiring diagram {Refer FIG 4.a & FIG 4.b}. Relay terminals are suitable for 2.5 mm. sq. lugs. Fix the protective cover back on the terminal block with the help of four screws after completing the wiring.
NOTE: 1. ENSURE PROPER EARTH CONNECTION TO THE RELAY.2. IT IS RECOMMENDED TO REMOVE THE RELAY
FROM THE PANEL DURING TRANSPORTATION.
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2.3.1 CT/ PT Connections
PFCR has a built-in CT which can accept current input from 1Amp or 5Amp CT. This input is to be taken from R phase CT output. Connect the current input to terminals 19 and 20 if it is from 1Amp CT and to terminals 19 and 21 for 5Amp CT.
PFCR has a built-in PT, which accepts 415V AC RMS voltage input. This input should be taken between Y and B phases. Connect terminal 22 to Y phase and 23 to B phase.NOTE : MAINTAIN PHASE CONNECTION AS SHOWN IN WIRING DIAGRAM {FIG 4.a & FIG 4.b}.
2.3.3 Wiring Of Capacitor Banks
PFC 14 (PFC 8) has 14 (8) relays each with one N/O contact available on terminals 1to 15(8). One pin of all N/O contacts is shorted together internally and this common point is available on terminal 12. Using these contacts an external contactor can be switched ‘ON’ or ‘OFF’ to connect or disconnect a capacitor bank as indicated in the wiring diagram {FIG 4.a & FIG 4.b}.
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Depending on configuration of capacitor banks, connect all banks to PFCR through contactor as mentioned below :
1. If the capacitor banks are in the ratio of 1:1:1:1..., i.e., all banks are of same value, then connect thecapacitor banks to relays R1 to Rn where ‘n’ is the number of banks selected.
2. If the capacitor banks are in the ratio of 1:2:2:2..., then connect the smallest capacitor bank to relay R14 (R8) and remaining banks to relays R1 to Rn-1 where ‘n’ is number of capacitor banks selected.
3. If the capacitor banks are in the ratio of 1:2:4:4..., then connect the smallest capacitor bank to relay R14 (R8), the next higher to R13 (R7) and remaining banks to relays R1 to Rn-2 where ‘n’ is number of capacitor banks selected.
4. If the capacitor banks are in the ratio of 1:2:4:8:8..., then connect the smallest capacitor bank to relay R14 (R8), the next higher to R13 (R7), the next one to R12 (R6) and remaining banks to relays R1 to Rn-3 where ‘n’ is number
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of capacitor banks selected.
2.3.4 Wiring Of Alarm Contacts
PFCR incorporates one relay to give alarm indication. One sC/O contact is available on terminal 16, 17 and 18 which can be used to initiate remote alarm. Note that this relay is wired in Fail-Safe mode i.e., it remains energized under healthy conditions.The wiring diagram shows the contact position in power ‘OFF’ condition {alarm relay de-energized}, hence under ‘healthy’ condition terminal 16, 17 will be open and terminal 17, 18 will be shorted.
Alarm relay drops out to initiate alarm under following conditions:
Over Voltage Under Compensation Over compensation Under current
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2.3.5 Commissioning
Switch ‘ON’ voltage and current inputs to PFCR.Check input connections polarity {Refer Section 3.1.2}.Verify the number of banks selected {Refer Section 3.1.3}.Adjust C/K control {Refer Section 2.2.2 and Annexure I}.Set the desired power factor {Refer Section 2.2.1}.
SECTION III
OPERATION
3.1 Operation
PFCR continuously monitors the reactive current drawn by the load and computes the power factor which will be displayed continuously. It compares the load power factor with set power factor and switches the relays inside ‘ON’ or ‘OFF’ which in turn can be used to connect or disconnect the capacitor banks.
To achieve hunt free operation, if reactive current measured is less than 66% of the available bank size, it will not be switched ‘ON’.
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PFCR switches the capacitors in cyclic order so that all the capacitors are used equally and allows longer discharge time. This increases the life of the capacitor bank.
In cyclic switching, if capacitor banks are in the ratio of 1:1:1:1.. always bank no. 1 is switched ‘ON’ first. The capacitor that was switched ‘ON’ or ‘OFF’ first will be switched ‘OFF’ or ‘ON’ first after utilizing all capacitors.
If it is other than 1:1:1.., then all capacitor banks of equal size will be used for rotational scheme.
3.1.1 Auto/Manual mode
PFCR can be used in AUTO or MANUAL mode.Normally after power ‘ON’ it will be in AUTO mode, indicated by a LED marked ‘AUTO’. In this mode PFCR automatically connects or disconnects the capacitor banks to maintain the load power factor as close as possible to the set power factor. The switching
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delay between two consecutive banks can be set at 10, 20, 40 or 60 secs by the user {Ref. Sec. 2.2.5 for details}.
Pressing Auto/Manual switch will change the operating mode of the unit from Auto to Manual or vice-versa. Operating mode is indicated by glowing of appropriate LED. In MANUAL mode user can switch ‘ON’ or ‘OFF’ the capacitor banks by operating the buttons marked CAP+ or CAP- respectively. The switching delay between two consecutive banks is fixed at 3 sec in MANUAL mode irrespective of the switching delay selected by the user for AUTO mode operation.
A row of fourteen (eight) LEDs marked 1 to 14 (8) indicates ‘ON’/’OFF’ status of each relay in AUTO as well as MANUAL mode.
3.1.2 Testing Of Input Connections
Any time after power ‘ON’, correctness of input connections {CT and PT connections for proper phase relation} can be checked as follows:
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Select MANUAL mode by pressing Auto/Manual button.
Press both CAP+ and CAP- buttons together. Display will show code ‘1’ if connections are correct and code ‘2’ if connections are reversed {& ALARM Relay operates}. Error Code LED will also glow.If code ‘2’ is displayed, then reverse either CT or PT connections {but not both}.
For correct indication of CT and PT polarity, more than 10% of the rated current should be flowing through the PFCR.
3.1.2.a Testing Output relays
The output relays can be tested by switching ‘ON’ DIP switch 3 which is located at right corner of the front panel. The DIP switch should be set ‘ON’ before powering the PFCR. Test will switch ‘ON’ and ‘OFF’ the output relays one after the other starting from one, the front capacitor bank LED will indicate. The PFCR
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will be in this mode as long as this DIP switch is ‘ON’. So after one cycle of testing switch it ‘Off ’ to come out of test mode.
3.1.3 Verifying Number Of Capacitor Banks Selected
User can select capacitor banks between 4 and 14 for PFC 14 & between 4 and 8 for PFC 8 {Refer Sec 2.2.3 for details}. Number of banks selected can be checked anytime by pressing both SET COS φ and SET C/K buttons in AUTO mode. The number will be displayed on the seven segment display.
3.1.4 Power Factor Display
Load power factor is continuously displayed on two seven segment LED displays at all load conditions. Power factor display is available in both AUTO and MANUAL modes. The three LEDs marked ‘Lead’, ‘Lag’ and ‘OK’, mounted next to this display indicates status of load power factor with respect to set power factor.
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Eg. If Set Power Factor is 0.80 and actual power factor is less than 0.80, then ‘Lag’ LED will glow. Whereas if actual power factor is greater than 0.80 ‘Lead’ LED will glow even if it is less than unity.
NOTE : THE DISPLAY INDICATES TWO DIGITS AFTER THE DECIMAL POINT. THE DECIMAL POINT IS NOT INDICATED.
3.1.5 Alarms and Protections
PFCR incorporates a separate relay which can be used to initiate remote alarm under certain conditions. Alarm conditions are also indicated on the front panel by displaying various ‘ERROR-CODES’.
3.1.6 Over Voltage Protection
If line voltage goes beyond 120% of nominal voltage {415 V} for three seconds, all relays are switched ‘OFF’ at once. Alarm relay operates and CODE ‘4’ is displayed. When voltage drops to less than 105% of nominal value, PFCR will start switching ‘ON’ the capacitor banks again automatically.
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3.1.7 Under Compensation
Even after switching ‘ON’ all the capacitor banks if measured reactive current {inductive} is more than the set C/K level {i.e., measured power factor is lagging with respect to set power factor} Under Compensation CODE ‘5’ will be displayed on the front panel and Alarm relay will operate.
3.1.8 Over Compensation
Even after switching ‘OFF’ all the capacitor banks if measured reactive current {capacitive} is more than desired C/K level {i.e., measured power factor is leading with respect to set power factor} Over Compensation CODE ‘6’ will be displayed and Alarm relay will operate.
3.1.9 Under Current Release
If load current is less than 10% of the CT rating {1A/5A} then all banks will be switched ‘OFF’sequentially. Alarm CODE ‘3’ is displayed.
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3.2 Maintenance
PFCR does not need any routine maintenance during its working life. It does not contain any user serviceable / replaceable parts. In case of failure of the PFCR inform nearest L & T office or dealer.
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SECTION IV
SPECIFICATIONS
Voltage Input 415VAC ± 20% , 50Hz .Current Input 5A / 1A {Field selectable}.Accuracy of PF Display 2% from 0.7 lag to 0.8 lead,
{under full load condition}.Desired Power Factor setting
0.80 lag to 0.95 lead.
Threshold reactive current setting {C/K}
0.05 to 1 Amps reactive.
Capacitor bank selection 4-5-6-7-8-10-12-14{PFC 14};4-5-6-7-8 (PFC 8);banks through DIP switch setting.
Capacitor bank switching delay
10, 20, 40, 60 sec +/- 10%.
Safety lockout time 60 sec + capacitor bank switching.Delay selected +/- 10%.
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Capacitor bank configuration
1:1:1:1:1:...1,1:2:2:2:2:...2,1:2:4:4:4:...4,1:2:4:8:8:...8.
Auto / Manual operation ‘AUTO/MANUAL’.Relay output rating N/O contact,
230VAC, 5A.Burden ona) PT
b) CT
Operational indicator
InsulationImpulse testNoise interference testOn line testing
Less than 10VA {at nominal voltage}.Less than 0.3VA{at nominal current}.LED for all Relays,LED for ‘ALARM’,LED for ‘AUTO/MANUAL’,7-Segment Display to show ‘PF’ & ‘Error Codes’.As per IS : 3231-1986.As per IS : 8686-1977.As per IS : 8686-1977.PFC relays can be tested using DIP switch.
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Operating temperatureOverall Dimension
0 to 55°C.144 Χ 144 mm;depth 100 mm.Conforms to IS 3231-1986 Standards for all requirements.
Fig. 3 : Panel Cutout Drawing
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SECTION V
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ANNEXURE 1.
KVARCT ratio
3 4 5 6 7.5 8.3 10 12.5 16.7 20 25 30 33.3 40 50
30/5 0.46 0.60 0.76 0.9050/5 0.27 0.36 0.45 0.55 0.68 0.7575/5 0.18 0.24 0.30 0.36 0.45 0.50 0.60 0.75100/5 0.14 0.10 0.23 0.28 0.34 0.38 0.45 0.57 0.75 0.90150/5 0.09 0.12 0.15 0.10 0.23 0.25 0.30 0.38 0.50 0.60 0.75 0.90200/5 0.07 0.09 0.12 0.14 0.17 0.19 0.23 0.28 0.38 0.45 0.57 0.68 0.75 0.90300/5 0.05 0.07 0.08 0.09 0.12 0.13 0.15 0.19 0.25 0.30 0.38 0.45 0.50 0.60 0.75400/5 0.05 0.06 0.07 0.09 0.10 0.12 0.15 0.19 0.23 0.29 0.34 0.38 0.45 0.57600/5 0.05 0.06 0.07 0.08 0.10 0.13 0.15 0.19 0.23 0.25 0.30 0.38800/5 0.05 0.05 0.06 0.08 0.10 0.12 0.15 0.17 0.19 0.23 0.291000/5 0.05 0.06 0.08 0.09 0.12 0.14 0.15 0.18 0.231500/5 0.06 0.07 0.08 0.09 0.10 0.12 0.132000/5 0.05 0.06 0.07 0.08 0.09 0.122500/5 0.05 0.06 0.07 0.08 0.103000/5 0.05 0.06 0.07 0.084000/5 0.05 0.06
TABLE : C/K VALUES
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WARRANTYLARSEN & TOUBRO LIMITED ( L&T) warrants that the protective Relay model PFC-14/PFC-8 will meet L&T ‘s published specifications and will be free from defects in workmanship and materials for a period of 12 months from the date of shipment. L&T’s obligation under this warranty shall be limited to servicing or replacing the defective parts provided that notice of such defects and satisfactory proof thereof is given to L&T by it’s customer within the warranty period.
This warranty does not cover any defect caused by accident, misuse, neglect alteration, modification or substitution of any of the components or parts or any attempts at internal adjustment by unauthorized service personnel.
Under no circumstances shall L&T will liable for any consequential damage, resulting injury, loss or expanse, directly or indirectly, arising from the use of this product.
This forgoing warranty is in lieu of all other warranties expressed or implied and is the sole and exclusive remedy for any claim arising from the defect in the product.
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Manufactured byLARSEN & TOUBRO LIMITED,KIADB INDUSTRIAL AREA,HEBBAL, HOOTAGALLY,MYSORE – 570 018.Visit us @ www.lntmps.com
www.lntebg.comwww.larsentoubro.com
Reach us @ [email protected]
Part No. 4D060079 Rev 2
