Electric Power Voltage Sag Solutions:
Coil-Hold-in-Devices (Coil-Locks)
Presented by:Power Quality Solutions, Inc. (PQSI)
Knoxville, Tennessee USA
February 2009
Symptoms of Electric Power Quality Problems
Power Quality problems are …
… failure or misoperation
… of customer end-use equipment
… caused by voltage, current or frequency deviations
The Voltage Sag Solution: PQSI Coil-Locks
A cost-effective, low intrusive way to
protect your vital equipment from
voltage sags and dips.
Energy User Surveys*
Most devices will operate here
Devices protected by a Coil-Lockswill operate here
*Electric Power Research Institute (EPRI), Canadian Electric Associations (CEA), and National Power Laboratory (NPL)
Typical Number of Facility Voltage Incidents/Year
Your TextVoltage Deviation < 0.02 Seconds Up to 3 Seconds
110-120% > 700 0 – 6
106 – 110% > 700 0 – 200
87 – 106% Normal Normal
70 – 87% > 240 20 – 140
25 – 87% > 240 0 - 16
Typical Number Facility Voltage Sag Events*
The PQSI
Coil-Lock is not
time based,
therefore it
maintains
operation during
sag events.
*Electric Power Research Institute (EPRI), Canadian Electric Associations (CEA),and National Power Laboratory (NPL)
Typical Voltage Sags in RMS Terms
Your Text
Your Text
Your TextExample of a Voltage Sag RMS Variation
Voltage Sags
(RMS Disturbance)
Power QualityVariation Category
Magnitude & Duration
•Utility System Faults•Motors Starting•Load Variations•Weather Conditions
Your TextMethod of
Characterization
Your TextTypical Causes
Typical Voltage Sag Events* in Real-Time Terms
* Voltage sag 50% depth with duration that can vary from 8 milliseconds to > 3 seconds due to across the line motors starting
in industrial processes, air conditioners, and utility activities.
Duration (4 Cycles)
Magnitude (50% of Nominal)
0 1 32 4 5 6 7 8
1
0.5 –
0
-0.5 –
-1 –
Process Solenoid Relay & Contactor OperatedDevices that can “trip” with
25% Voltage Sag Events
PQSI Coil-Lock Coil-hold-in-DeviceProtects for 75% Deep Sags
(i.e. 25% Remaining Voltage)
PQSI Coil-Lock Coil-hold-in-DeviceProvides SEMI F47 Voltage Sag Immunity
Note 1: This point (50% sag for 12 cycles) initially failed for L3-L1 sags with a “High Velocity Pressure Sprayer” fault, but passed for L1-L2 and L2-L3 sags.
100
90
80
70
60
50
40
30
20
10
0
0.01 0.02 0.1 1 10 100
Equipment required to
Operate in this region
Equipment not required to
Operate in this region
See Note 1 forExplanation of this
Pass/fail point
LegendPassFail, but not required to passFail
Area included in Specification 0.05 to
1 Second
Duration of Voltage Sag in Seconds
Voltage Sag Immunity – SEMI F47SEMI Stepper/Washer, 240V 50 Hz power
Model 2200, SN 99SW4502, 5/00
Per
cen
t o
f E
qu
ipm
ent
No
min
al V
olt
ag
e
*
*
PQSI Coil-Lock Applications
2
1Coil-Locks Eliminate Weak Links …
Coil-Locks Eliminate Costly Equipment Shutdown …
Relays, contactors, and motor starters are used extensively in commercial and industrial facilities to control business machines and process equipment. These devices often have a low tolerance to electric service voltage sags, and are frequently diagnosed as “weak links” in automated production lines.
During common voltage sags, the solenoid coils in these motor-driven systems may de-energize long enough to cause the power circuit mechanical contacts to open (chatter), and the connected electrical equipment to shutdown. The Coil-Lock eliminates costly process shutdown, installs in minutes, and can be a cost-effective alternative to other voltage sag protection methods.
3Coil-Locks Eliminate Disruption of Operations …
This situation can impact an entire manufacturing facility The Coil-Lock is available in different models to be compatible with most solenoid operated relays and contactors, and is ideal for protecting master control relays, and E-stop circuits.
.
Good Place to Begin “Hardening”:Emergency Off (EMO) Circuit (Simplified)
PQSI Coil-Lock: Simple Installation
PQSI Coil-Lock: Field Installations
Coil-Lock
Coil-Lock
Coil-Lock
Coil-Lock
NEMA Size 1
NEMA Size 5 SEMI F47 Equipment
NEMA Size 3
PQSI Coil-Lock: 120Vac & 240Vac Models
Coil-Lock 120Vac Models
Coil-Lock 240Vac Models
Cost BreakdownsSag Protection
OptionsInitialCost
InstallationCost
Maintenance Cost
Life CycleCost
PQSI Coil-Lock $ $ None
RequiredFixed
Voltage Dip Proofing Inverter $$$ $$
Storage/Mech
DevicesVariable
Constant Voltage Transformer (CVT) $$ $$ None
RequiredFixed
Dynamic Sag Corrector (DYSC) $$$$ $$
Storage/Mech
DevicesVariable
Uninterruptible Power Supply (UPS) $$$$ $$
Storage/Mech
DevicesVariable
Know-Trip $$ $ None Required
Variable
PQSI Coil-Lock: Selective Power Conditioning
Summary
Power line variation impacts such as Voltage sags can be minimized with PQSI Coil-Locks.
Strategy
Challenges Forward
History
Knowledge of the electricalenvironment can help in applying PQSI Coil-Locks
to present processequipment and the
design of new equipment.
Collaboration between end-users, utilities, and manufacturers can be cost-effective
in solving these power quality issues.
Power line variation impacts such as
voltage sags can be minimized with PQSI Coil-Locks.
Special Thanks to:
EPRI, CEA, and NPL Corporations for
use of their ongoing Power Quality
System Compatibility Research
Prepared by Power Quality Solutions, Inc.
Knoxville, TN USA
Thank You!