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Instruction Leaflet

ABB 41-116.1C

Effective: March 2000 Type COV Voltage Controlledvercurrent Relay
Supersedes I.L. 41-116.1B dated September 1999 O
Class 1E Applications
( ) Denotes Change Since Previous Issue
R

CAUTION!Before putting relays into service, remove allblocking which may have been inserted for thepurpose of securing the parts during shipment,make sure that all moving parts operate freely,inspect the contacts to see that they are cleanand close properly, and operate the relay tocheck the settings and electrical connections.

This instruction leaflet applies to the followingtypes of relays:

TYPE TIME CHARACTERISTIC

COV-6 Definite Minimum TimeCOV-7 Moderately Inverse Time COV-8 Inverse Time COV-9 Very Inverse Time COV-11 Extremely Inverse Time

1.0 APPLICATIONThe type COV relay is applicable where it is desiredthat an overcurrent unit be set to operate on less thanfull load current when the voltage falls below a prede-termined value, and it is desired not to operate for anymagnitude of current when the voltage is above thepredetermined value. A typical application is overcur-rent back-up protection for generators.

These relays have been specially designed andtested to establish their suitability for Class 1E appli-cations in accordance with the ABB Relay Divisionprogram for Class 1E Qualification Testing, asdetailed in Bulletin STR-1. Materials have beenselected and tested to insure that the relays will per-

form their intended functions for their design life whenoperated in a normal environment as defined inANSI/IEEE standard C37.90, when exposed to radia-tion levels up to 104 rads, and when subjected toseismic events producing a Shock Response Spec-trum within the limits of the relay rating.

“Class 1E” is the safety classification of the electronicequipment and systems in nuclear power generatingstations that are essential to emergency shutdown ofthe reactor, containment isolation, cooling the reactor,and heat removal from the containment and reactor,or otherwise are essential in preventing significantrelease of radioactive material to the environment.

2.0 CONSTRUCTION AND OPERATIONThe relay consists of: (see Figure 1, page 10).

1. an overcurrent unit (CO)

2. a voltage unit (V) with adjustable resistor

3. an indicating contactor switch unit (ICS)

4. a slow-release telephone type relay, (T)

2.1 OVERCURRENT UNIT (CO)

The electromagnets for the types COV-6, COV-7,COV-8 and COV-9 relays have a main tapped coillocated on the center leg of an “E” type laminatedstructure that produces a flux which divides andreturns through the outer legs. A shading coil causesthe flux through the left leg to lag the main pole flux.The out-of-phase fluxes thus produced in the air gapcause a contact closing torque.

The electromagnet for the type COV-11 relay has amain coil consisting of a tapped primary winding. Twoidentical coils on the outer legs of the laminationstructure are connected to the main coil secondary ina manner so that the combination of all the fluxes pro-

All possible contingencies which may arise during installation, operation or maintenance, and alldetails and variations of this equipment do not purport to be covered by these instructions. If furtherinformation is desired by purchaser regarding this particular installation, operation or maintenanceof this equipment, the local ABB Inc. representative should be contacted.

Printed in U.S.A.

41-116.1C COV Voltage Controlled Overcurrent Relay

duced by the electromagnet result in out-of-phasefluxes in the air gap. The out-of-phase air gap fluxesproduced cause a contact closing torque.

2.2 VOLTAGE UNIT (V)

The voltage unit is an induction type cylinder typeunit.

Mechanically, the voltage unit is composed of fourbasic components: A die-cast aluminum frame, anelectromagnet, a moving element assembly, and amolded bridge.

The frame serves as the mounting structure for theelectromagnet and for a magnetic core. The mag-netic core houses the lower pin bearing and issecured to the frame by a locking nut. The bearingcan be replaced if necessary, without having toremove the magnetic core from the frame.

The electromagnet has two pairs of voltage coils.Each pair of diametrically opposed coils is connectedin series. In addition, one pair is in series with anadjustable resistor. These sets are paralleled asshown in Figure 2, page 11. The adjustable resistorserves not only to shift the phase angle of the oneflux with respect to the other to produce torque, but italso provides a dropout adjustment.

Locating pins in the electromagnet are used to accu-rately position the lower pin bearing, which ismounted on the frame, with respect to the upper pinbearing, which is threaded into the bridge. The elec-tromagnet is secured to the frame by four mountingscrews.

The moving element assembly consists of a spiralspring, contact carrying member, and an aluminumcylinder assembled to a molded hub which holds theshaft. The shaft has removable top and bottom jewelbearings. The shaft rides between the bottom pinbearing and the upper pin bearing with the cylinderrotating in an air gap formed by the electromagnetand the magnetic core. The stops for the moving ele-ment contact arm are an integral part of the bridge.

The bridge is secured to the electromagnet andframe by two mounting screws. In addition to holdingthe upper pin bearing, the bridge is used for mount-ing the adjustable stationary contact housing. Thestationary contact housing is held in position by aspring type clamp. The spring adjuster is located onthe underside of the bridge and is attached to themoving contact arm by a spiral spring. The springadjuster is also held in place by a spring type clamp.

With the contacts closed, the electrical connection is

made through the stationary contact housing clamp,to the moving contact, through the spiral spring out tothe spring adjuster clamp.

2.3 INDICATING CONTACTOR SWITCH UNIT (ICS)

The indicating contactor switch is a small dc oper-ated clapper type device. A magnetic armature, towhich leaf-spring mounted contacts are attached, isattracted to the magnetic core upon energization ofthe switch. When the switch closes, the moving con-tacts bridge two stationary contacts, completing thetrip circuit. Also during this operation two fingers onthe armature deflect a spring located on the front ofthe switch, which allows the operation indicator targetto drop. The target is reset from the outside of thecase by a push rod located at the bottom of thecover.

The front spring, in addition to holding the target, pro-vides restraint for the armature and thus controls thepickup value of the switch.

3.0 CHARACTERISTICSTo prevent the relay from operating for currentsabove the overcurrent unit pickup, the voltage unitcontact is connected to control the telephone relaywhose contacts are connected in the shading coil cir-cuit of the overcurrent unit. The voltage contact isheld open at voltage above the set point, to preventtorque from being produced in the overcurrent unit.This arrangement yields a tripping characteristic asshown in Figure 3, page 12.

3.1 OVERCURRENT UNIT

The relays are generally available in the followingovercurrent unit ranges:

These relays may have either single or double circuitcontacts for tripping either one or two circuit break-ers.

The time vs. current characteristics are shown in Fig-ures 4 to 8, starting on page 13. These characteris-tics give the contact closing time for the various timedial settings when the indicated multiples of tap valuecurrent are applied to the relay

3.2 VOLTAGE UNIT

The contacts can be adjusted to close and energize

RANGE TAPS

0.5 - 2.52 - 6

4 - 12

0.5 0.6 0.8 1.0 1.5 2.0 2.52 2.5 3 3.5 4 5 64 5 6 7 8 10 12

2

41-116.1CCOV Voltage Controlled Overcurrent Relay

the slow-release telephone relay over a range of 80to 100 volts. The contacts open to de-energize thetelephone relay if the voltage is higher than the setvalue. The drop-out ratio of the unit is 98% or higher.Relays are shipped from the factory with a 90 voltsetting.

3.3 TRIP CIRCUIT

The main contacts will safely close 30 amperes at250 volts dc and the seal-in contacts of the indicatingcontactor switch will safely carry this current longenough to trip a circuit breaker.

3.4 TRIP CIRCUIT CONSTANTS

Indicating Contactor Switch Coils.

4.0 RELAY SETTINGS

CAUTION!In order to avoid opening current transformer cir-cuits when changing taps under load, start withRED handles FIRST and open all switchblades.Chassis operating shorting switches on the casewill short the secondary of the current trans-former. Taps may then be changed with the relayeither inside or outside the case. Since the tapblock screws carry operating current, be surethat the screws are turned tight. Then reclose allswitchblades making sure the RED handles areclosed LAST.


The overcurrent unit setting can be defined by tapsetting and time dial position or by tap setting and aspecific time of operation at some current multiple ofthe tap setting (e.g. 4 tap setting, 2 time dial positionor 4 tap setting, 0.6 seconds at 6 times tap value cur-rent). The tap setting is the minimum current requiredto make the disc move.

To provide selective circuit breaker operation, a mini-mum coordinating time of 0.3 seconds plus circuitbreaker time is recommended between the relaybeing set and the relays with which coordination is to

be effected.

The connector screw on the terminal plate above thetime dial makes connections to various turns on theoperating coil. By placing this screw in the variousterminal plate holes, the relay will respond to multi-ples of tap value currents in accordance with the var-ious typical time-current curves.

The factory adjustment of the CO unit contactsprovides a contact follow. Where circuit breakerreclosing will be initiated immediately after a trip bythe CO contact, the time of the opening of the con-tacts should be a minimum. This condition isobtained by loosening the stationary contact mount-ing screw, removing the contact plate and thenreplacing the plate with the bent end resting againstthe contact spring.

For double trip relays, the upper stationary contact isadjusted such that the contact spring rests solidlyagainst the back stop. The lower stationary contact isthen adjusted such that both stationary contact makecontact simultaneously with their respective movingcontact.


The voltage unit spring calibration is set to close itscontact when the applied voltage is reduced to 80volts. The voltage unit can be set to close its contactsfrom 80 volts to 100 volts by adjusting the resistorlocated at the top left of the voltage unit. The spiralspring is not disturbed when making any setting otherthan the calibrated setting of 80 volts.

4.3 INDICATING CONTACTOR SWITCH (ICS)

There are no settings to make on the indicating con-tactor switch (ICS).

5.0 INSTALLATIONThe relays should be mounted on switchboard pan-els or their equivalent in a location free from dirt,moisture, excessive vibration and heat. Mount therelay vertically by means of the four mounting holeson the flange for the semi-flush type FT case. Themounting screws may be utilized for grounding therelay. External toothed washers are provided for usein the locations shown on the outline and drilling planto facilitate making a good electrical connectionbetween the relay case, its mounting screws and therelay panel. Ground wires should be affixed to themounting screws as required for poorly grounded orinsulated panels. Other electrical connections maybe made directly to the terminals by means of screws

Ampere Pickup Ohms dc Resistance

0.2 8.5

1.0 0.37

2.0 0.10

3


for steel panel mounting.

For detail information on the FT case refer to IL 41-076 for semi-flush mounting.

Ref. Dwgs: External Schematic (Figure 10, page 19)Outline and Drilling Plan (Figure 11,page 20)

6.0 ACCEPTANCE TEST

CAUTION!High currents left on for excessive time periodscan result in the softening and possible meltingof the insulation of the interconnecting wires.

The proper adjustments to insure correct operation ofthis relay have been made at the factory. Uponreceipt of the relay, no customer adjustments, otherthan those covered under “RELAY SETTINGS”,should be required.

The following check is recommended to insure thatthe relay is in proper working order. (See Figure 9,page 18.)


The directional unit contacts must be in the closedposition and the “T” unit picked up when checking theoperation of the overcurrent unit.

A. Contact

1) By turning the time dial, move the movingcontacts until they deflect the stationary con-tact to a position where the stationary contact

is resting against its backstop. The indexmark located on the movement frame shouldcoincide with the “O” mark on the time dial.For double trip relays, the follow on the sta-tionary contacts should be approximately1/64”.

2) For relays identified with a “T”, located atlower left of stationary contact block, theindex mark on the movement frame will coin-cide with the “O” mark on the time dial whenthe stationary contact has moved throughapproximately one-half of its normal deflec-tion. Therefore, with the stationary contactresting against the backstop, the index markis offset to the right of the “O” mark byapproximately .020”. The placement of thevarious time dial positions in line with theindex mark will give operating times as shownon the respective time-current curves. Fordouble trip relays, the follow on the stationarycontacts should be approximately 1/32”.

B. Minimum Trip Current – Set the time dial toposition 6. Alternately apply tap value currentplus 3% and tap value current minus 3%. Themoving contact should leave the backstop attap value current plus 3% and should return tothe backstop at tap value current minus 3%.

C. Time Curve – Table 1 shows the time curvescalibration points for the various types ofrelays. With the time dial set to the indicatedposition, apply the currents specified by Table1 (e.g., for the COV-8, 2 and 20 times tap value

4

Table 1:

PermanentMagnet Adjustment

ElectromagnetPlug Adjustment

RelayType

TimeDial

Position

Current(Multiples ofTap Value)

OperatingTime

(Seconds)

Current(Multiples ofTap Value)

OperatingTime

(Seconds)

6 6 2 2.46 20 1.19

7 6 2 4.27 20 1.11

8 6 2 13.35 20 1.11

9 6 2 8.87 20 0.65

11 6 2 11.27 20 0.24*

* For 50 hertz COV-11 relay, 20 times operating time limits are 0.24 + 20%, -5%


current) and measure the operating time of therelay. The operating times should equal thoseof Table 1 plus or minus 5%.

For type COV-11 relay only, the 1.30 times tapvalue operating time from the number 6 timedial position is 54.8 ± 5% seconds and shouldbe checked first. It is important that the 1.30times tap value current be maintained accu-rately. The maintaining of this current accu-rately is necessary because of the steepnessof the slope of the time-current characteristic(Figure 8, page 17). A slight variation, ± 1%, inthe 1.3 times tap value current (including mea-suring instrument deviation) will change thetiming tolerance to ± 10% and the effects of dif-ferent taps can make the total variationsappear to be ± 15%.


1) Contact Gap – The gap between the station-ary contact and moving contact with the relayin a de-energized position should beapproximately .020”.

2) Sensitivity – The contacts should close whenvoltage is reduced to approximately 90 volts.


Close the main relay contacts and pass sufficient dccurrent through the trip circuit to close the contacts ofthe ICS. This value of current should not be greaterthan the particular ICS nameplate rating. The indica-tor target should drop freely.

Repeat above except pass 85% of ICS nameplaterating current. Contacts should not pickup and targetshould not drop.

6.4 TELEPHONE RELAY (T)

The telephone relay has a dropout time of 250milliseconds ± 50 milliseconds. It has a burden of1.56 watts at 125 volts dc nominal. It should pickupwhenever the voltage unit contacts close.

7.0 ROUTINE MAINTENANCEAll relays should be inspected and checked once ayear or at other time intervals as dictated by experi-ence to assure proper operation. Generally a visualinspection should call attention to any noticeablechanges. A minimum suggested check on the relaysystem is to close the contacts manually to assurethat the breaker trips and the target drops. Thenrelease the contacts and observe that the reset is

smooth and positive.

If an additional time check is desired, pass second-ary current through the relay and check the time ofoperation. It is preferable to make this at severaltimes pick-up current at an expected operating pointfor the particular application. For the .05 to 2.5amperes range CO-6 induction unit use the alterna-tive test circuit in Figure 9 (page 18) as these relaysare affected by a distorted waveform. With this con-nection the 25/5 amperes current transformersshould be worked well below the knee of the satura-tion (i.e., use C 50 or better).

All contacts should be periodically cleaned. A contactburnisher S#182A836H01 is recommended for thispurpose. The use of abrasive material for cleaningcontacts is not recommended, because of the dangerof embedding small particles in the face of the softsilver and thus impairing the contact.

8.0 CALIBRATIONUse the following procedure for calibrating the relay ifthe relay has been taken apart for repairs or theadjustments disturbed. This procedure should not beused until it is apparent that the relay is not in properworking order (see “ACCEPTANCE TEST”).

NOTE: A spring shield covers the reset spring ofthe CO unit. Removing the spring shieldrequires that the damping magnet beremoved first. The screw connection hold-ing the lead to the moving contact shouldbe removed next. The second screw hold-ing the moving contact assembly shouldthen be loosened, not removed. (Caution:this screw terminates into a nut held cap-tive beneath the molded block. If screw isremoved, difficulty will be experienced inthe re-assembly of the moving contactassembly.) Slide the spring shield outwardand remove from relay. Tighten the screwholding the moving contact assembly tothe molding block.


A. Contact

1) By turning the time dial, move the movingcontacts until they deflect the stationary con-tact to a position where the stationary contactis resting against its backstop. The indexmark located on the movement frame shouldcoincide with the “0” mark on the time dial.For double trip relays, the follow on the sta-

5


tionary contacts should be approximately1/64”.

2) For relays identified with a “ T ”, located atlower left of stationary contact block, theindex mark on the movement frame will coin-cide with the “0” mark on the time dial whenthe stationary contact has moved throughapproximately one-half of its normal deflec-tion. Therefore, with the stationary contactresting against the backstop, the index markis offset to the right of the “0” mark byapproximately .020”. The placement of thevarious time dial positions in line with theindex mark will give operating times as shownon the respective time-current curves. Fordouble trip relays, the follow on the stationarycontacts should be approximately 1/32”.

3) Set the time dial in position 6.

B. Minimum Trip Current

The adjustment of the spring tension in settingthe minimum trip current value of the relay ismost conveniently made with the dampingmagnet removed.

With the time dial set on “O”, wind up the spiralspring by means of the spring adjuster untilapproximately 6-3/4 convolutions show.

The spiral spring can be adjusted with thespring shield in place as follows. One slot ofthe spring adjuster will be available for a screw-driver in one window of the front barrier of thespring shield. By adjusting this slot until a bar-rier of the spring shield prevents further adjust-ment, a second slot of the spring adjustmentwill appear in the window on the other side ofthe spring shield barrier. Adjusting the secondslot in a similar manner will reveal a third slot inthe opposite window of the spring shield.

Adjust the control spring tension so that themoving contact will leave the backstop at tapvalue current + 1.0% and will return to thebackstop at tap value current -1.0%.

C. Time Curve Calibration – Install the perma-nent magnet.

Apply the indicated current per Table 1 for thepermanent magnet adjustment (e.g., COV8, 2times tap value) and measure the operatingtime. Adjust the permanent magnet keeperuntil the operation time corresponds to thevalue of Table 1.

For type COV-11 relay only, the 1.30 times tapvalue operating time from the number 6 timedial position is 54.9 ± 5% seconds. It is impor-tant that the 1.30 times tap value current bemaintained accurately. The maintaining of thiscurrent accurately is necessary because of thesteepness of the slope of the time-currentcharacteristic (Figure 8, page 17). A 1% varia-tion in the 1.30 times tap value current (includ-ing measuring instrument deviation) willchange the nominal operating time by approxi-mately 4%. If the operating time at 1.3 timestap value is not within these limits, a minoradjustment of the control spring will give thecorrect operating time without any undue effecton the minimum pick-up of the relay. Thischeck is to be made after the 2 times tap valueadjustment has been completed.

Apply the indicated current per Table 1 for theelectromagnet plug adjustment (e.g. COV-8, 20times tap value) and measure the operatingtime. Adjust the proper plug until the operatingtime corresponds to the value in Table 1. (With-drawing the left-hand plug, front view,increases the operating time and withdrawingthe right-hand plug, front view, decreases thetime.) In adjusting the plugs, one plug shouldbe screwed in completely and the other plugrun in or out until the proper operating time hasbeen obtained.

Recheck the permanent magnet adjustment. Ifthe operating time for this calibration point haschanged, re-adjust the permanent magnet andthen recheck the electromagnet plug adjust-ment.


A. The upper pin bearing should be screweddown until there is approximately. 0.25” clear-ance between it and the top of shaft bearing.The upper pin bearing should then be securelylocked into position with the lock nut. The lowerbearing position is fixed and cannot beadjusted.

B. The contact gap adjustment for the directionalunit is made as follows:

With the moving contact in the normally-closedposition i.e., against the left stop on bridge,screw in the stationary contact until both con-tacts just close as indicated by a neon lamp inthe contact circuit. Then, screw the stationarycontact in toward the moving contact an addi-

6


7

tional one-half turn. The clamp holding the sta-tionary contact housing need not be loosenedfor the adjustment since the clamp utilizes aspring-type action in holding the stationarycontact in position.

C. The sensitivity adjustment is made in twosteps:

1) The adjustable resistor, located at the top leftof the voltage unit, is adjusted such that themaximum resistance is in the circuit (approxi-mately 2500 ohm).

2) The tension of the spiral spring, attached tothe moving element assembly, is then varied.The spring is adjusted by placing a screw-driver or similar tool into one of the notcheslocated on the periphery of the springadjuster and rotating it. The spring adjuster islocated on the underside of the bridge and isheld in place by a spring type clamp that doesnot have to be loosened prior to making thenecessary adjustments.

The spring is to be adjusted such that the contactswill close (indicated by pickup of telephone relay “T”)when the applied voltage is reduced to 80 volts. Thecontacts should open with 80 plus volts applied.

Any setting other than the 80 volts then can be madeby adjusting the resistor for the desired contact clos-ing voltage.


Initially adjust unit on the pedestal so that armaturefingers do not touch the yoke in the reset position(viewed from top of switch between cover and frame).This can be done by loosening the mounting screw inthe molded pedestal and moving the ICS in thedownward position.

a) Contact Wipe – Adjust the stationary contact sothat both stationary contacts make with themoving contacts simultaneously and wipe 1/64”to 3/64” when the armature is against the core.

b) Target – Manually raise the moving contacts andcheck to see that the target drops at the sametime as the contacts make or up to 1/16” ahead.The cover may be removed and the tab holdingthe target reformed slightly if necessary. How-ever, care should be exercised so that the targetwill not drop with a slight jar.

c) Pickup – The unit should pickup at 98% ratingand not pickup at 85% of rating. If necessary, thecover leaf springs may be adjusted. To lower thepickup current use a tweezer or similar tool andsqueeze each leaf spring approximate equal byapplying the tweezer between the leaf spring andthe front surface of the cover at the bottom of thelower window.

If the pickup is low, the front cover must beremoved and the leaf spring bent outwardequally.

8.4 TELEPHONE RELAY (T)

No calibration is required. The telephone relayshould have a dropout time of 250 msec. ±50 msec.

9.0 RENEWAL PARTS

Repair work can be done most satisfactorily at thefactory. However, interchangeable parts can be fur-nished to the customers who are equipped for doingrepair work. When ordering parts, always give thecomplete nameplate data.

Class 1E certification of a repaired relay is theresponsibility of the agent who makes the repair.

ENERGY REQUIREMENTSVOLTAGE UNIT

FrequencyDrop-out

Adjustment VoltsMaximum

Volts Continuous

Volt-Ampere†

Burdenat 120 Volts

Drop-outRatio

60 80-100 132 8.0 98%

†Volt-Ampere burden is average for the various settings.


COV-6 OVERCURRENT UNITS

AmpereRange Tap

ContinuousRating *

(Amperes)

One SecondRating *

(Amperes Ø

PowerFactor

Angle Ø

Volt Amperes * *

AtTap ValueCurrent

At 3 TimesTap ValueCurrent



0.5/2.5

0.50.60.81.01.52.02.5

2.73.13.74.15.76.87.7

88888888888888

69686766626058

3.923.963.964.074.194.304.37

20.620.721.021.423.224.926.2

103106114122147168180

270288325360462548630

2/6

22.533.5456

8.08.89.710.411.212.513.7

230230230230230230230

67666463625957

3.883.903.934.094.124.204.38

21.021.622.123.123.524.826.5

110118126136144162183

308342381417448540624

4/12

456781012

16.018.819.320.822.525.028.0

460460460460460460460

65636159565347

4.004.154.324.374.404.604.92

22.423.725.326.427.830.135.6

126143162183204247288

376450531611699880

1056

ENERGY REQUIREMENTS

COV-7 OVERCURRENTS UNITS

AmpereRange Tap

ContinuousRating

(Amperes)

One SecondRating *

(Amperes)

PowerFactor

Angle Ø

Volt Amperes * *

AtTap ValueCurrent



At 20 Times Tap ValueCurrent

0.5/2.5

0.50.60.81.01.52.02.5

2.73.13.74.15.76.87.7

88888888888888

68676664615856

3.883.933.934.004.084.244.38

20.720.921.121.622.924.825.9

103107114122148174185

278288320356459552640

2/6

22.533.5456

88.89.710.411.212.513.7

230230230230230230230

66636363615958

4.064.074.144.094.344.404.62

21.321.822.523.123.825.227

111120129136149163183

306342366417448530624

4/12

456781012

1618.819.320.822.52528

460460460460460460460

64616058555146

4.244.304.624.694.805.205.40

22.824.225.927.329.83337.5

129149168187211260308

3924605406266888601032

* Thermal capacities for short times other than one second may be calculated on the basis of time being inversely proportional to the square of the current.

Ø Degrees current lags voltage at tap value current.* * Voltages taken with high impedance type voltmeter.

8

41-116.1C

9

COV Voltage Controlled Overcurrent Relay

COV-8 INVERSE TIME AND COV-9 VERY INVERSE TIME RELAYS

AmpereRange Tap

ContinuousRating

(Amperes)

One SecondRating *

(Amperes)

Power Factor

Angle Ø

VOLT AMPERES * *

AtTap ValueCurrent




0.5/2.5

0.50.60.81.01.52.02.5

2.73.13.74.15.76.87.7

88888888888888

72716967625753

2.382.382.402.422.512.652.74

212121.121.22223.524.8

132134142150170200228

350365400440530675800

2/6

22.533.5456

88.89.710.411.212.513.7

230230230230230230230

70666462605856

2.382.402.422.482.532.642.75

2121.121.52222.72425.2

136142149157164180198

360395430470500580660

4/12

456781012

1618.819.320.822.52528

460460460460460460460

68636057544845

2.382.462.542.622.733.003.46

21.321.822.623.624.827.831.4

146158172190207248292

4204805506207008501020

TYPE COV-11 RELAY

AmpereRange Tap

ContinuousRating

(Amperes)

One SecondRating *

(Amperes)

Power Factor

Angle Ø

VOLT AMPERES * *

AtTap ValueCurrent




0.5/2.5

0.50.60.81.01.52.02.5

1.71.92.22.53.03.53.8

88888888888888

36343027221716

0.720.750.810.891.131.301.48

6.546.807.468.3010.0411.9513.95

71.875.084.093.1115.5136.3160.0

250267298330411502610

2/6

2.02.53.03.54.05.06.0

7.07.88.39.010.011.012.0

230230230230230230230

32302724232020

0.730.780.830.880.961.071.23

6.307.007.748.209.129.8011.34

74.078.584.089.0102.0109.0129.0

264285309340372430504

4/12

4.05.06.07.08.010.012.0

14161718202226

460460460460460460460

29252220181716

0.790.891.021.101.231.321.8

7.088.009.1810.0011.114.916.3

78.490.0101.4110.0124.8131.6180.0

296340378454480600720

* Thermal capacities for short times other than one second may be calculated on the basis of time being inversely proportional to the square of the current.

Ø Degrees current lags voltage at tap value current.* * Voltages taken with high impedance type voltmeter.

ENERGY REQUIREMENTS


TelephoneRelay (T)

Overcurrent Unit (CO)

Indicating ContactorSwitch (ICS)

1342D82A01Photo

Voltage UnitAdjustable Resistor

VoltageUnit (V)

Figure 1: Type COV Relay without case

10


*Sub 63526A40

Figure 2: Internal Schematic of the Type COV Relay in the Type FT-21 Case (For Class 1E Application)

11


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TRIP AREAx

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LTA

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RM

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CURRENT IN PERCENT OF FULL LOAD

The Trip Area May be Changed as Follows:

The line “bc” may be moved in the direction of arrow “y” by changing the voltage unit setting. The line“ab” may be moved in the direction of arrow “x” by changing the CO unit tap setting. Tap value currentexpressed in % Full Load defines line ab, and voltage unit setting expressed i n% normal voltage de-fines line bc.

esk0399

Figure 3: Typical Tripping Characteristics of Type COV Relay

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619511Sub 1

Figure 4: Typical 50 and 60 hertz Time Curves of COV-6 Overcurrent Unit

13


619512Sub 1


14


619513Sub 1


15


619514Sub 1


16


619515Sub 1


17

41-116.1C

18

COV Voltage Controlled Overcurrent Relay

1582

C85

*Sub

6

Fig

ure

9: D

iag

ram

of

Test

Co

nn

ecti

on

s o

f C

OV

Rel

ays


*Sub 23531A56

Figure 10: External Schematic of the COV Relay on a Generator

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