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!