Manual Multi Amp1

Bullelln -3 SR77

I"Uiti•amp CORPORATION

4271 Bronze Way Dalias, Texas 75237·1088 U.S.A. Mu!ti-Amp Canada, 445 Finchdenc Square, Scarborough, Ontario, M1X 187 Ph. (214) 333·3201 Telex 163548 MULAM DL Fax (214) 333-3533 Ph. (416) 298-6nO Telex 065-25453 Fax (416) 298-7214

Model SR-77 Resistance Load Protective Relay Test. Set

Model SR-77 ls housed In a two-plece unlt for ease of portabllity. The Reslstance Load/ Control Sectlon ls shown on the lett and the Transformer Load Sectlon ls on the rlght.

Multi-Amp® Model SR-77

General Description Combining the latest technological advances with durabllity and reliability, Modal SR-77 is the most versatlle and comprehensive resistance load protective relay test set available today. Oesigned for ease of operation and with the test technician's needs in mind, it is a rugged, self-contained unit incorporating all necessary outputs, instrumentation and control circuitry to test a wide variety of electromechanical and solid-state protective relays.

Engioeered to s1mplify test procedures, increase accuracy, reduce equlpment set-up time and eliminate winng errors which result when interconnecti ng individual components, Model SR-77 will withstand years of daily field use as well as the rigors of transportation between job sites. Nineteen different AC and OC outputs are provided together with severa! special test circuits which greatly simpllfy test procedures and increase testing1 effic iency. Model SR-77, with its test leads and instruction manual, is all that ls needed for testing virtually all the "basic" relays.

Applications Multi-Amp Model SR-77 is a universal test set ideal for fleld, shop or laboratory testing of elactromechanical and solid-state protective relays manufactured by such companies as General Electric, Westinghouse, Brown Boveri, Asea, English Electric, Siemens, Reyrolle, etc. Relays it tests include overcurrent, over/undervoltage, differential, directional overcurrent. current phase balance, pilot wire, reclosing, thermal, timing, voltage restraint overcurrent, voltage controlled overcurrent and various AC and OC auxiliaries.

Other devices which can be tested by Model SR-77 include small molded-case circuit breakers and magnetic or thermal motor overload relays. Additionally, it can be used in various miscellaneous applícations, such as calíbrating instruments and transducers, ratioing cJrrent transformers, as a multi-purpose variable power supply, etc. When used in conjunctlon with any Multi-Amp phase shlfter, Model SR-77 can be used to test single- or three-phase relays requiring control of the phase angle relationship. These would include retays such as distance (compensation, impedance, reactance, mho, ohm, etc.), reversa power, power directional, loss of excitation, loss of field, power, synchronizing, etc. Frequency relays are easily tested with a frequency generator.

Copyright Multi-Amp Corporation, "1988

Standard Features Many standard features are incorporated in Model SR-77 to reduce set-up time, simplify test procodures and lncrease accuracy: • Two Resistance Load Outputs: Two independenl 25-

ampere resistance load outputs with vernier control are provlded for conducting slope tests on the 5-ampere taps or the in-service taps of different1al relays.

• 50-Ampere Reslstance Load: A simple tront panelmounted togg le switch connects the two resil';IP!nc:e loads in parallel to provide a single 50-ampere load.

• Harmonic Restralnt Test Clrcuit: Utilizlrng the two resistance load outputs, complete facil ities (including built-in diode and ammeters) are provided to easily conduct harmonic restraint tests on differential relays equipped with a harmonlc restraint element. No additional components or metering equipment is necessary.

• Wide-Range lnstrumentatlon: Built-in lnstruments provide excellent resolution to measure low currents (as when using the O.SA range to check pickup of a generator differential relay) or to measure high currents when setting lnstantaneous elements.

• Digital Tímer: A solid-state digital tlmer with associated solid-state control circuitry ensures accurate timing measurements. To assure excellent readability in high ambient light conditions, including direct sunlight, the timer has a high-intensity, gas-discharge, flat, planar display instead of nixie tubes or light-emitting diodes.

• lnltlatlng Control Clrcuit: Provides both "momentary" and "maintained" modesto control output duration. The momentary mode permits "pulsed" application of the output to avoid damage or overheating of the relay while setting the test current. In the maintained mode. the output remains energizad until manually turned off, or when performing timing tests, until the relay under test operates ... Which both stops the timer and deenergizas the output. Facilities are also provided to in itlate the out put from a remo te locatlon.

• SCR Circult: This 100% sol id-state circuit is used in conjunction with the test set's digital timer when testing solid-state relays whose tfi p circuits "fi re" an S CA. No externa! components or additional circuitry is required ... the relay's trip circuit SCR is connected directly to binding posts on the test set. The circuit senses the firing of the relay's trip circuit SCR and stops the digital timer to indicate the operating time of the relay. This circuit eliminates the timing error present when the timer iMiatlng and control circuitry is not completely solidstate.

• OC Logic Voltage: Facilities are provided so that rated OC logic voltage can be applied to a solid-state relay prior to initiating the test.

• Contact Monitor: Contact action can be monitored by eitl'ler a paMI lamp oran audible tone signa!.

• Voltage Relay Test Circuit: A special circuit to simplify testing over/undervoltage relays rated up to 300 volts AC.

• Drop-Out Test: With this special circuit, the drop-out time of DC relays is measured.

• Non-Reflectlve Glass Windows: To eliminate glare and static build-up, all instruments are equipped with non-reflective glass windows.

• Externa! Use· of lnstrumentation: The unit's AC/ DC voltmeter can be used to measure external AC or OC potentials up to 300 volts. Addit ionally, the AC ammeter in the transformer load section can be used to measure external currents up to 250 amperes and the digital timer can be used to make timing measurements independent of using the test set's outputs.

• Overload and Short-Circuit Protection: Fuses and circuit b reakers provide protection from prolonged overloads or short circuits.

• Cooling: The resistance load current source is forced-air cooled and a tertlperature-sensing interlock prevents overheating.

• Auxiliary Channel: Completely independent of the main outputs, the auxiliary channel may be fed from a common primary source or from an externa! phase shifter o r frequency generator.

Specifications

Input Voltage (specify one): 120 vo lts OR 240 volts, 50/60 Hertz, 1</>

Outputs:

Resistance Load/Control Sectíon No. 1: Ohm Spun® Resistance Load: Oto 25 amperes at

120 vo lts AC with O to 1 ampere vernier for fine contro l. (Oto 12 amperes at 240 volts, 240 volt input test set).

No. 2: Second Ohm-Spun Resistance Load: Oto 25 amperes at 120 volts AC with O to 1.0 ampere vernier for fine control. (O to 12 amperes at 240 volts, 240-volt input test set). .

No. 3: Ohm-Spun Resistance Load: Oto 50 amperes at 120 volts AC with two Oto 1 ampere verniers for fine cont rol. Front-panel toggle switch parallels outputs No. 1 and No. 2 to produce this output. (O to 24 amperes at 240 volts on 240-volt input test sets).

No. 4: O to 10 amperes at 120 volts half-wave rectified AC current output (resistance load) with O to 1 ampere vernier for use in conducting harmonic restraint tests on differential relays. (Oto 12 amperes at 240 volts, 240-volt input test set).

No. 5: Oto 40 amperes at 120 volts (resistance load) with O to 1 ampere vernier for use as the "bypass" or restraint current when conducting harmonic resistant tests. (Oto 12 .amperes at 240 volts on 240-volt input test sets).

No. 6: O to 8 volts DC at 5 amperes for testing OC targets, operation indicators and seal-in units.

Transformer Load Section (all outputs are isolated) No. 7: Oto 10 volts AC at 100 amperes (1.0kVA) No. 8: o to 20 volts AC at 50 amperes (1 .0kVA)

No. 9: o to 40 vofts AC at 25 amperes (1 .0kVA) No. 10: Oto 80 volts AC at 12.5 amperes (1.0kVA)

No. 11: Oto 160 volts AC at 6 amperes (1.0kVA) When the above output voltages are sufficient to push higher than rated current through the impedance of the load circuit, the current ratings can be exceeded for short durations. Up to 250 amperes can be obtained.

No. 12: Oto 300 volts AC at 0.5 amperes No. 13: Oto 24 volts AC at 6.0 amperes No. 14: Oto 150 volts AC at 1.0 amperes No. 15: Oto 300 volts AC at 0.5 amperes No. 16: o to 150 volts DC at 1.0 a m peres No. 17: Oto 300 volts DC at 0.5 amperes No. 18: 500-volt DC insulation resistance test source

(current limited) No. 19: Voltage Relay Test: This special circuit simplifies

testing of voltage relays (under, over, or over/undervoltage) rated up to 300 volts AC. Facilities are provided to adjust and apply a normal operating voltage up to 300 volts to the relay while also independently adjusting a second output to the desired fault vol.tage up to 300 volts. A switching circuit changes the voltage applied to the relay from the normal operating voltage to the simulated fault voltage and simultaneously starts the timer to measure the operating time of the relay. The timer stops and the test voltage is removed when the relay operates.

1 nstrumentation AC Ammeter

True RMS-responding moving iron-vane type instrument equipped with non-reflective glass, mirrored scale, knife-edge pointer and pointer preset mechanism to aid in measuring currents of short duration.

Scales: 5/10/25 amperes Ranges (switch-selected): Oto 0.5/1/2.5/5/10/25/50

amperes AC Accuracy: ± 1% of full scale

AC Ammeter True RMS-responding moving iron-vane type instrument equipped with non-reflective glass, mirrored scale, knife-edge pointer and pointer preset mechanism to aid in measuring currents of short duration .

Scales: 5/10/25 amperes Ranges (switch-selected): O lo 1/2.5/5/10/25


OC Ammeter D'Arsonval movement inst rument equipped with nonreflective glass, mirrored scale and knife-edge pointer.

1 Scales: 0.5/5 am·peres Ranges (switch-selected): Oto 0.5/5 amperes OC Accuracy: ± 1% of full scale

AC Ammeter True RMS-responding moving iron-vane type instrument equipped with non-reflective glass, mirrored scale, knife-edge pointer and pointe r preset mechanism to aid in measuring currents of short duration. This ammeter may also be used asan independent instrument in conjunction with the ammeter range switch to measure external currents up to 250 ampares.

Scales: 5/10/25 amperes Ranges (switch-selected): Oto 1/2.5/5/10/25/50/100/250


lnstrumentation (continued) Multi-Function AC/DC Voltmeter

Low burden, rectifier-type instrument equipped with non-reflective glass, mirrored scale and knife-edge pointer. This voltmeter may be used as an independent instrument in conjunction with the voltmeter range switch to measure externa! AC or OC voltages up to 300 volts.

Scales: 15/30/75 volts AC, 50 megohms 15/30/75 volts OC

Ranges (switch-selected): Oto 1.5/7 .5/30/75/150/ 300 · volts AC or DC; 10 megohms

Accuracy: ± 1% of full scale

Solid-St.ate Digital Timer A specially designed Multi-Amp solid-state digital timer is incorporated to measure the elapsed time of the test in seconds or cycles. lt has extensiva shielding and noise suppression circuitry to ensure accurate and reliable operation under the most demanding field conditions. lncorporating a crystal-controlled oscillator, accuracy of the timer is independent of the power line frequency. The readout display appears as continuous, solid, unbroken digits with no gaps between the segments to impair readability. The high brightness-to-contrast ratio of the display ensures excellent readability even in high ambient light conditions, including direct sunlight. The flat, planar design of the display allows wide-ang le viewing without distortion.

Display: .375-inch (9.53mm), flat, planar characters using high-intensity, gas-discharge technology Ranges (switch-selected): a) O to 99.9999 seconds

b) Oto 9999.99 seconds e) O to 99999.9 cycles

Accuracy: Seconds Mode: ± least significan! digit

or 0.0025% of reading, whichever is.greater

Cycles Mode: ± 0.5 cycle

Protection Input and outputs are protected from short-circuit~ and prolonged overloads. Cooling fans are provided ln the Resistance Load Section and a temperature-sensing interlock prevents overheating.

Enclosure The test set is housed in two heavy-duty formica cases, each equipped with carrying handles and hinged, removable covers which protect instruments and controls during transportation and storage. A single, multiple conductor cable with keyed connectors (Part No. 3335) is provided to interconnect the two sections. Control Resistance Load Section can be used independently for complete testing of overcurrent, current balance, differential and thermal relays.

Weights and Dimensions:

Resistance Load/Control Sectíon 87.5 lbs. (39.7 kg) 17H X 22W X 160 in. (432 X 559 X 406 mm)

Transformer Load Section 66 lbs. (29.9 kg) 17H X 14W X 110 in. (432 X 356 X 279 mm)

Leads:

The following test leads are supplied at no add itional charge:

No. 18 potential leads, four pair .... ......... Part No. 1282 Leads with telephone-type plug, two pair ..... Part No. 1283 High-voitage ieads, one pair ... .. ......... ... Part No. íí25 High-current leads, two pair ................. Part No. 4328 High-current leads, one pair . . ............... Part No. 1285 High-current leads, one pair ... . . . . ..... ..... Part No. 333,7'

l"'!l!~:.~mp 4271 Bronze Way Dalias, Texas 75237-1088 U.S.A. Ph. (214) 333-3201 Telex 163548 MULAM DL Fax (214) 333-3533

Printed in U.S.A.

Multi-Amp Canada, 445 Finchdene Square, Scarborough, Ontario, M1 X 187 Ph. (416) 298·6770 Telex 065-25453 Fax (416) 298-7214

MA-4997 ClJ JII o.t l.-. 'l CO ~""'7 lAII 1t=t. 6. 1t::~1

I"Uiti--mp CORPORATION

4271 Bronze Way Dalias. Texas 75237-1088 U.S.A. Multf-Amp Canada, 445 Finchdene Square. Scart>orough, Ontario, M1X 187 Ph. (214) 333-3201 Telex 163548 MULAM DL Fax (214) 333-3533 Ph. (416) 298-6nO Telex 065·25453 Fax (416) 298-7214

INSTRUCTION MANUAL

For

RESIST ANCE LOAD PROTECTIVE RELAY TEST SET

MODEL SR-77

SERIAL NO. rLtr:so~

lt is essentialthat this instruction book be read thoroughly beforei putting the equipment in service.

IM- 525- MA PB/25/1290

P/N 12442 Rev. O

IMPORTAN!'

The information and data contained within this instruction manual are proprietary with MULTI-AMP Corporation. The equipmem described herein may be prorecred by one or more U. S. letters patent. MULTI-AMP speci.fically reserves to irself all rights to such proprieraty information as well as al/ rights under any such patent, none of which is waived by the submission of this instruction manual to anyone.

The recipient, if a Government agency, acknowledges rhat this instruction book and the equipment described were procured with "Limited Rights" to technical data as described in ASPR 9-203 (b).

Copyright MULTI-AMP Corporation, 1979, 1990

P/ N 12442 Ri! Y. o

TABLE OF CONTENTS SECTION PAGE

GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BuJJetin

THEORY OF OPERATION .................................... .

DESCRIPTION OF CONTROLS AND INSTRUMENTA TI ON LARGER SECTION (RESISTANCE LOAD/CONTROL SECTION) . . . . . . . . 2 AUXILIARY SECTION (TRANSFORMER LOAD SECTlON) . . . . . . . . . . . 7

AC AMMETER CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

SELECTION OF INPUT AND OUTPUT TAPS . . . . . . . . . . . . . . . . . . . . . . . 12

SERVICE DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 WARRANTY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

TESTING PROCEDURES TESTING INDUCTJON DISC OYERCURRENT RELA YS Westinghouse Type CO & General Electric Type lAC .............. , . 15

TESTING INDUCTJON OVER/ UNDER VOLT AGE Westinghouse Type CV & General Electric IAY ......... .. ... . , , . . 22

TESTING PERCENTAGE DIFFERENTIAL RELAYS Westinghouse Type CA & General Electric Type UD . . . . . . . . . . . . . . . . 25

TESTING HARMONIC RESTRAINT DIFFERENTIAL RELA YS Westinghouse Type HU & General Electric Type BDD . . . . . . . . . . . . . . . 30

TESTING I.T.E. CIRCUIT SHIELD . . . . . . . . . . . . . . . . . . . . . . . . . . 32

SOLID-ST A TE OVERCURRENT RELA YS . . . . . . . . . . . . . . . . . . . . . . 32

TESTING lNSULA TION RESISTAN CE . . . . . . . . . . . . . . . . . . . . . . . 36

TYPICAL TESTS FOR DC AUXlLIARY RELAYS . . . . . . . . . . . . . . . . . 38

TESTJNG VOLTAGE RESTRAJNT OVERCURRENT RELAY . . . . . . . . . . . . . . 41

TESTING VOLTAGE CONTROLLED OVERCURRENT RELA Y Westinghouse Type COY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

TESTING OVERCURRENT PHASE BALANCE RELA Y General Electric IJC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

PIN 124-12 Rev. O

T ABLE OF CONTENTS (Continued) SECTION PAGE

TESTING CURRENT PHASE BALANCE RELA Y Westinghouse Type CM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

SCHEMATIC AND PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

11 P/N 12442

R~v.O

THEORY OF OPERA TION

Multi-Amp Model SR-77 is housed in two heavy-duty formica enclosures, each equipped with carrying handles and removable hinged covers which protect instruments and controls during

transportation and storage. A single, multiple conductor cable with locking plugs on each end is provided to interconnect the two sections. Facilities are incorporated so that up to five independent outputs can be obtained simultaneously.

The larger section incorporates the two channel, 50 ampere (24 ampere for 240V units) OhmSpun resistance load and the five ampere DC current output, which is used for testing DC targets, operation indicators and seal-in units. This section also contains the harmonic restraint test circuit, primary controls of the test set along with the solid-state ctigital timer.

The smaller section contains all other outputs of the test set.

Model SR-77 is designed so that the resistance load/control section can be used for the convenience in testing overcurrent relays and similar devices. To obtain the output from the smaller sectio:n, the two must be interconnected.

1 P/N 12442

· Rcv. O

DESCRIPTION OF CONTROLS AND INSTRUMENTATION LARGER SECTION (RESISTANCE WAD/CONTROL SECTION)

The control section of the Model SR-77 comprises three output channels of the test set; two resistance loads are controlled by a bank of toggle switches and 0-1 ampere verniers, the other output channel is controlled by the small DC Control Knob. The following is a description of the controls and instrumentation in the control section.

INITIA TE Button

EXT. INITIA TE J ACK

POWER ON LIGHT

RELA Y CONT ACTS BINDING POSTS (White)

S.C.R. TRIP BINDING POSTS (Red +, Black -)

POWER ON/OFF BREAKER

INPUT, 129 Volt, 50/60 Hertz (Red Binding Posts)

INPUT, 240 Volt, 50/60 Hertz (Red Binding Posts)

GND. BINDING POST (Green)

The INITIA TE Button serves to start operation of the test set. An internal light indicates whenever the INITlA TE Button is depressed.

The test set can be initiated remotely by closing a circuir plugged into the EXT. INITIATE JACK.

The POWER ON Light incticates that the main circuit is in the ON position and that input power to the test set is available.

Binding posts where the trip circuit contacts of electromechanical relays or solid-state relays not utilizjng an SCR are to be connected.

Binding posts where the SCR trip circuit of solid-state relays are connected.

Functions as main input switchlbreaker for the test set.

A 15 ampere, 120 volt source can be used if the resistance load is not operated above 10 amperes. A 60 ampere source is required if the resistance load is to be used at full capacity.

A 7.5 ampere, 240 volt source can be used if the resistance load is not operated above 10 amperes. A 30 ampere source is required if the resistance load is to be used at full capacity.

Equipment ground.

2 PIN 12442

R~v. O

CONTROL ClRCUIT

Tbe control circuit of Model SR-77 provides facilities for observing contact action by use of a CONTINUITY Ligbt ora TONE generator as well as timing of devices with normally closed (NC) contacts, or from the "firing" (conduction) of an SCR. Operation of the control circuit is determined by the INJTIATE CONTROL Selector Switch, which is divided into two sections (knob and lever). A description of each section follows:

LEVER SECTION This switch connects the RELAY CONTACTS Binding Posts to three different circuits in order to eliminate the need to change the leads to various circuits.

DC: In this position, the RELAY CONTACTS Binding Posts are connected in parallel with the DC OUTPUT Binding Posts for convenience in testing target and seal-in units on relays.

The timer will not run and closure of the contacts of the device under test will not de-energize the test set. Only the position N.O. MOM. and N.O. MAINT. of the Knob Section may be used for this position of the lever.

CONT: In this position, the RELA Y CONT ACTS Binding Posts are connected to the continuity circuit. Therefore, contact operaúon of the relay under test may be observed by the CONTINUITY Light. If desired, contact action can be monitored by the TONE Generator by switching the TONE/CONTINUJTY Switch to the tone position. When the TONE Generator is being used, the CONTINUITY Light will not indicate.

TIMER: In this position, the RELA Y CONTACTS Binding Posts or SCR TRIP Binding Posts are used in conjunction with the knob Section of the switch to supervise relay action and control the operation of the digital timer.

NOTE: When the lever is in the TIMER posilion, it is necessary to reset the digital timer by depressing the red RESET Button on the timer befare the test set cam be initiated. Should the test set fail to initiate upon depressing the INITIA TE Button, reset the timer and then reinitiate. If the timer still fails to initiate, check the DC 150/300V, DROPOUT/NORMAL Switch to make sure it is in the NORMAL position. When the lever is in either the CONT. or DC position, it is normally not necessary to depress the RESET Button to reinitiate the test set; however, occasionally, it will be necessary to reset the timer if it fails to start.

3 P/N 12442

Rev. O

KNOB SECTION

CONTINUITY Light

TONE/CONTINUITY

DC AMMETER

DC AMPS 0-0.5/5A Range Switch

DC Control

PUSH FOR DROPOUT Switch

0-5A DC OUTPUT Binding Posts (Red + , Black -)

RESISTANCE LOAD AC AMMETERS

N.O. MOM. (NORMALLY OPEN MOMENTARY):

When the relay under test has normally open contacts which are connected to the RELA Y CONT ACT Terminals, the test set may be initiated by depressing the INITIATE Button. The selected outputs of the test set will remain energized as long as the INITIATE Switch is held depressed or until the contacts of the device under test close.

N.O. MAINT. (NORMALLY OPEN MAINTAINED):

The function of this position is exactly the same as above except the INITIA TE Button need be depressed o ni y momentarily to lick in an interna! relay which maintains the output of the test set. The selected outputs will remain energized and the timer will run until the contacts of the device under test open, at which time the output will be deenergized and the tirner will stop to indicate the elapsed time of the test.

A low voltage continuity circuit is provided for use in conjunction with the RELA Y CONT ACTS Bind.ing Posts to observe contact action of a relay or monitor circuit continuity, when the TONE/CONTINUITY Switch and the INITIATE CONTROL Lever are in the INITTA TE CONTROL Lever are in the CONTINUITY position.

In place of the CONTINUITY Light, a TONE Generator can be used to monitor contact action or circuit continuity. When contact closure occurs, an audible tone is generated when the TONE/CONTINUITY Switch is in the TONE position. When the TONE Generator is used, the CONTINUITY Light does not operate.

Indicates magnitude of the DC output currenL

Selects full scale range of the DC A m meter.

Controls magnitude of DC output current.

De-energizes DC current output in order to verify the seal-in of DC targets, operation indicators and seal-in units. Push for dropout, release for pickup.

Binding posts where the DC current output is obtained.

Measures the current output of the 0-50 ampere Ohm-Spun resistance load.

4 PIN 12442

Rev. O

RESISTANCE LOAD Ammeter Range Switches

Selects the full scale range for the RESISTANCE LOAD AMMETERS.

RESISTANCE LOAD OUTPUT CONTROL SWITCHES

SPLIT/PARALLEL Switch

TOGGLE STEP Switches

RESISTANCE LOAD Output Terminals

HARMONIC RESTRAINT/NORMAL Switch

P .A.M. JACK

This switch controls the two RESISTANCE LOAD Output Channels. When in the SPLIT position, there are two 25 amp channels available (12 amp channels, 240 volt input). The current from Channel One will appear on one 0-25A ammeter and Channel Two current will appear on the 0-50A ammeter. When in the PARALLEL position, the current will be read on the 0-50A ammeter and the small binding post and 0-25A ammeter will be bypassed.

These switches control the amount of current available at the output terminals. In addüion, two 0-1 ampere verniers are provided for fine adjustment of the output.

Two sets of terminals are provided for the output of the RESIST ANCE LOAD. In the P ARALLEL position, a maximum of 50 amperes are available on the 0-50A ammetei (24 amperes, 240 volt unit). When in the SPLIT position, 0-25 amperes are available from each channel of the RESIST ANCE LOAD Section (0-12 amperes, 240 volt u ni t) and can be read on the appropriate ammeter.

In the NORMAL position , the harmonic restraint circuitry is completely isolated. in the test set. When switched to the HARMONIC RESTRAINT position, the output terminals of Channels One are dead and Channel Two will provide both the DC and AC current needed to conduct the test. The first four step switches of Channel One will provide control of the DC current to Channel Two and will appear on the DC A mm e ter. The 5 and 1 O ampere step switches will be tied to Channel Two and will allow approximately 40 amperes of AC current to be obtained from Channel Two Output Terminals. (For the 240 volt unit, the 2.5 and 5 ampere step switches will allow approximately 15 amperes of curren t.)

NOTE: When the Resistance Load is in operation, care should be exercised not obstruct the air intake and exhaust gri11s. The fans will operate whenever the main breaker is switched ON. After use of the Resistance Load, the main breaker should be left ON long enough for the generated heat to be dissipated.

A 5 ampere fuse protects the resistance load cooling fans as well as providing primary protection for the test set's control circuitry.

5 P/N 12442

Rev. O

PUSE F2, 0.5A, REG.:

FUSE F3, 3A, START

PUSE F4, l.SA, TIMER

FUSE F7, 1.5A, DC

A 0.5 ampere fuse protects the regulator and TONE Generator.

A three ampere fuse protects the timer start CIRCUITRY.

A 1.5 ampere fuse protects the initiate circuitry and the solid-state digital timer.

A 1.5 Ampere fuse protects the 0-5 ampere DC current output.

6 P/N 12442

Rev. O

AUXILIARY SECTION (TRANSFORMER LOAD SECTION)

TRANSFORMER LOAD AC AMMETER

0-300 Y.A.C. or TRANSFORMER LOAD CONTROL Knob and Selector switch and Associated Output Terminals

P. A. M. Jack

AUXILIARY OR VERN. Control Knob and AUXILIARY SELECTOR Switch:

(a)

(b)

(e)

VERN:

AUX. AC 24/1 50/300:

V. RELAY:

Measures the output current of the Transformer Load Ammeter.

The large control knob functions in conjunction with the 0-300 V.A.C./TRANSF. LOAD Selector Switch to control the output from the main Transformer Load. When the selector switch is in the 0-300 V.A.C. position, 0-300 volts AC is available at the yellow and white binding posts marked 0-300 V.A.C The AC/DC Voltmeter can be used in conjunction with the VOLTMETER SELECTOR Switch 0-300 V .A.C. position and the VOLTMETER Range Switch to measure the voltage output. When the selector switch is in the TRANSFORMER LOAD AC AMMETER. For the convenience of making quick connections under light loads, this small binding post can be used. For heavier loads, the plug-in terminals should be used.

An extemal jack is provided in series with the secondary of the current transformer on the TRANSFORMER LOAD AMMETER for connections of externa! instrumentation when necessary, such as a phase angle meter.

The AUXILIARY OR VERNIER Control Knob functions in conjunction with the AUXILIARY SELECTOR Switch to provide control of the associated AC and DC outputs. The outputs associated with the positioning of the AUXILIAR Y SELECTOR Switch are as follows:

When the AUXILIARY SELECTOR Switch is in the VERN position, the Control Knob will function as a vernier to the 0-300 V.A.C. or adjustment of the outputs.

In the AUX. AC 241150/300 position, 0-24/150/300 volts AC at 6/0.5/0.25 amperes will be available at the white and yellow binding post marked AUX. AC 24/150/300V. The magnitude of the AC potential outputs can be measured by the AC/DC Voltmeter by selecting the appropriate range of the voltmeter with the VOL TMETER RANGE Switch and switching the VOLTMETER SELECTOR Switch to the AUX. AC position.

The 0-24 volt at 6.0 amperes position can be used as a third channeJ output current. An extemal ammeter would have to be used to measure the output current.

This position of the AUXILIARY SELECTOR Switch is provided for use in conjunction with the VOLTAGE RELA Y TEST Switch for the convenience in testing voltage relays.

7 P/N 12-l-12

Rev. O

(d)

(e)

(f)

DC 150/300:

J. RES.:

INITIATE BYPASS Switch:

ACIDC VOLTMETER:

VOLTMETER SELECTOR Switch:

VOLTMETER RANGE Switch:

POWER ON LAMP:

In th·e 150/300V position, 0-150/300 volts DC will be available at the red and black binding posts located below the DC 0-150/300V, NORMAL/DROPOUT Switch. The magnitude of the DC potential outputs can be measured by the AC/DC Voltmeter by selecting the appropriate range of the voltmeter with VOLTMETER RANGE Switch and switching the VOLTMETER SELECTOR Switch to the DC position.

This position of the AUXILIARY SELECTOR Switch is provided for use in conjunction with the 500 volt, DC insulation resistance test circuit.

This switch is used in conjunction with the AUX. OUTPUT in order to obtain a voltage without initiating the test set. When in the BYPASS position, an AC or DC voltage, up to 300 volts, can be obtained from the AUX. OUTPUT without having to initiate the test set. Wben in the NORMAL position, output cannot be obtained from the AUX. OUTPUT until the INITIA TE Switch is initiated.

The AC/DC VOLTMETER can be used in conjunction with the VOLTMETER SELECTOR Switch and VOLTMETER RANGE Switch to measure the various potential outputs of the test set.

This switch functions in conjunction with the AC/DC VOLTMETER and the VOLTMETER RANGE Switch to measure the potential outputs of the test set.

Selects the full scale of the AC/DC VOLTMETER.

This switch is used when running timing tests on voltage relays. The relay's potential coil is connected to the 0-24/150/300 V.A.C. Terminals.

NOTE: The VOLTMETER SELECTOR Switch must be in the VOLTAGE RELAY position, the AUXILIARY OR VERN. Switch must be in the V. RELA Y position and the 0-300 V.A.C./TRANSF. LOAD Switch must be in the 0-300 V.A.C. position before the speciaJ voltage relay test circuit can be used.

SET NORM Positioo In this position, the normal relay voltage is adjusted by the 0-300 V.A.C OR TRANSF. LOAD Main Control Knob.

SET FAULT Position

8 P/N 12442

Rev. O

DC 150/300 V. NORMAL/DROPOUT Switch:

l. RES. TEST/SET:

l. RES. TEST LAMP:

EXTERNAL/Internal Switch and EXT. POWER INPUT:

EXT. V.M. Binding Posts:

In this position, the fault voltage to be applied to the relay is set .by the AUXILIARY OR VERN. Control Knob and is read on the voltmeter while the normal relay voltage is maintained on the voltage relay.

TEST Position In this position, the fault voltage is automatically applied to the relay and at the same time, the digital timer is started. When the voltage relay closes its contacts, the digital timer stops to indicate the elapsed time of the test.

Functions to break the DC potential output. When the switch is thrown to the DROPOUT position, the DC supply is interrupted and the digital timer is automatically started to time the dropout of the DC relay.

NOTE: This switch must be in the NORMAL position before the timer can be used for all other timing functions.

This switch is used in conjunction with the AUXD...IARY OR VERN. Control, AUXILIARY SELECTOR Switch and VOLTMETER RANGE Switch for measuring insulation resistance. The AUXILIARY OR VERN. Control is used to precalibrate the megohm range on the AC/DC VOLTMETER to the infmity calibration mark with the TEST/SET Switch in the SET position. In the TEST position, 500 volts DC is applied and the insulation resistance can be read on the AC/DC VOLTMETER.

Indicates whenever the l. RES. TEST circuit is energized.

This switch selects energizing of the AUXILIARY or VERN. Control from an EXTERNAL or an INTERNAL Source. When energizing from an externa! source of power (not over 120 volts), such as from a phase shifter or frequency generator, the source is connected to the yellow and white binding posts. The potential is then controlled by the AUXILIARY OR VERN. Control and is available from the appropriate binding posts as determined by the AUXILIAR.Y SELECTOR Switch.

These binding posts enable the voltmeter to be used for measuring externa! AC or DC potential When using the voltmeter to measure an externa! potential, the VOLTMETER SELECTOR Switch and VOLTMETER RANG~ Switch should be used to select the proper type potential and proper range for the voltmeter.

9 P/N 12442

Rev. O

EXT. AMM. Binding Posts: These binding posts enable the TRANSFORMER LOAD AMMETER to be used to measure external AC currents . when using the voltmeter to measure an external current, the AMMETER RANGE Switch should be used to select the proper full scale range for the amrneter.

10 P/N 12442

R~v. O

AC AMMETER CIRCUITS

The AC output current of Multi-Amp SR-77 is read on ammeters connected in the output circuit by appropriate current transformers and ammeter range switches. The desired full scale value is selected by means of range switches.

The ammeters are moving iron-vane instruments of ± 1 % full scale accuracy. When using an indicating instrument of full scale accuracy, the user should use a range which will give an indication as close to full scale as possible. It should be noted that there is no relationship between the ammeter ranges and the rating of the output terminals. ANY AMMETER RANGE CAN BE USED WITH ANY OUTPUT TERMINAL.

The ammeters are equipped with an adjustable pointer preset mechanism, by which means the ammeter pointer may be preset to any position on the scale and held there with no current in the meter circuit. This is a mechanical operation accomplished by means of an insulated knob on the front of the meter. It is used to overcome the inertia of the moving system of the meter so that currents of short duration can be set or read accurately.

In use, the pointer is mechanically set approximately 1 division below the desired current. The device under test is connected to the test set and the output is momentarily turned on and then off (pulsed and jogged) severa! times with the INITIA TE BUTION. Prior to each energization of the output, the output current is increased by rotating the control knob. Sorne quivering of the pointer will be seen as the output current approaches the preset value. Continue to increase the output until the meter pointer lifts off the preset mechanism and moves up scale to the desired test current. At this point, hold the INITIA TE Button on long enough to be certain the ammeter needle has stabilized.

11 P/N 12442

Rev. O

INPUT

INPUT LEADS

OUTPUT LEADS

OUTPUT

SELECTION OF INPUT AND QUTPUT TAPS

Multi-Amp Model SR-77 is designed to be used on a 120 volt or 240 volt source. When the resistance load is to be used at full capacity, a 60 ampere, 120 volt source is required (of 30 ampere, 240 volt source). However, if the resistance load is not u sed above 1 O amperes a 15 ampere, 120 volt source (or 7.5 ampere, 240 volt source) can be u sed.

Due to the wide variation in individual user requirements, input leads are not supplied', however, input plugs which mate with input sockets are supplied with each unit. The individual user should choose the appropriate input cables to fit his/her requirements.

A variety of output leads are supplied with each unit as noted in the descriptive bulletin covering Model SR-77.

The TRANSFORMER LOAD SECTION of the Multi-Amp Model SR-77 may be operated most advantageously by using the tap with the lowest voltage rating consistent with being able to obtain the desired curren t. In this way, finer adjustment can be obtained by using the autotransformer range. With a low impedance load, even small currents may be obtained from the Low Voltage, High Current Tap. When the impedance of the load is too high to obtain the desired test current with the low voltage tap, it becomes riecessary to use a high voltage tap.

1T SHOULD BE NOTED THAT THERE IS NO RELATION BETWEEN THE AMMETER RANGES AND THE CURRENT TAPS. ANY AMMETER RANGE CAN BE USED ON ANY TAP.

Current taps are provided to adapt the test set output to a wide range of load impedances.

Ammeter ranges are provided to facilitate more accurate reading over a wider range of current values.

12 P/N 12442

Rev. O

SERVICE DATA

Multi-Amp Model SR-77 basically uses straight forward circuits and components requiring little or no routine servicing except for cleanliness.

The following maintenanoe is recommended:

l. Open the unit every six months and examine for:

a. Dirt b. Moisture c. Corrosion d. Condition of relay contacts

2. Remove dirt with dry compressed air.

3. Remove moisture by opening unit as muchas possible and putting it in a warm, dry environment.

4. As corrosion may take many forms, no specific recommendations can be made for the removal.

5. The contacts on relays and contactors should be examined for pitting and buming. The contacts on control relays and contactors may be bumished with a diamond dressing tool if not too badly damaged. If excessive pitting or buming has occurred, the relay or contactor should be replaced.

If factory service is required or desired, contact the factory for return instructions.

A Retum Authorization (RA) number will be assigned for proper handling of the unü wben it arrives at the factory.

If desired, a let~er with the number and instructions can be provided.

Provide the factory with model number, serial number, nature of the problem or service desired, retum address, your name, and where you can be reached should the factory need to contact you.

A purchase order number, cost limit, billing, and return shipping instructions may also be provided if desired.

National Institute of Standards and Technology recommends traceable calibration and certification once a year. Calibration and certification of two types is available if desired at an additional cost.

CLASS ONE:

CLASS N:

A certificate is provided verifying the traceability and calibration of the equipment.

That which is required for nuclear power plants. A certificate of traceability and calibration along with "as found" and "as left"

13 PIN 1244

Rev. C

data are provided.

If an estímate is requested, provide the name and contact information of the person with approval/disapproval authority.

Pack the equipment appropriately to prevent damage during shipment. If a reusable crate or container is used, the unit will be returned in it if in suitable condition.

Put the RA number on the address label of the shipping container for proper identification and faster handling.

WARRANTY

Multi-Amp Corporation warrants to the original purchaser that the product is free of defects in material and workmanship for a period of one (1) year from date of shipment. This warranty is limited and shall not apply to equipment which has damage, or cause of defect, dueto accident, negligence, improper operation, faulty installation by the purchaser, or improper service or repair by any person, company or corporation not authorized by MulliAmp Corporation.

Multi-Amp Corporation will, at its option, either repair or replace those parts and/or materials that it deems to be defective. Any costs incurred by the purchaser for the repair or replacement of such parts and/or materials shall be the sole responsibility of the original purchaser.

THE ABOVE WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EITHER EXPRESSED OR IMPLIED ON THE PART OF THE MULTI-AMP CORPORA TION, AND IN NO EVENT SHALL THE MULTJ-AMP CORPORATION BE LIABLE FOR THE CONSEQUENTIAL DAMAGES DUE TO THE BREACH THEREOF.

?IN 1244:!

14 Rev. O

TESTING INDUCTION DISC OVERCURRENT RELA YS WITH RESISTANCE LOADING

Westinehouse Type CO & General Electric Type IAC

The following procedure outlines the most efficient manner to consecutively perform all tests on an overcurrent relay. This procedure in vol ves the least possible number of changes in the connecting of test leads and setting of test controls.

The Resistance Load Section of Model SR-77 can be used independently from the Transformer Load Section for conducting all of the following tests:

TYPE OF TESTS

Zero Check Pickup - lnduction Unit Timing - lnduction Unit DC Target and Seal-ln Pickup lnstantaneous Pickup

ALWAYS REFER TO THE MANUFACTURER'S LITERATURE BEFORE TESTING

SET UP OF CONTROI.S BEFORE TEST RESISTANCE WAD UNIT

CONTROL POSITION

POWER ON/OFF Breaker OFF

INlTIA TE CONTROL Knob N.O. MOM.

INlTIATE CONTROL Lever CONT.

TONE/CONTINUITY Switch Either Position

DC AMPS Range Switch SA

DC Control o

RESISTANCE LOAD AMMETER Range Switch

To read test current on upper 1/3 meter sea! e

RESIST ANCE LOAD Controls



OFF

PARALLEL

NORMAL

NOTE: When the resistance load is not in use, the toggle control switches and verniers should be switched to the OFF position or there will be 120 volts AC across

15 P/N 12442

Rev. O

the output terminals (240 volts on 240 Volt unit).

ZERO CHECK

This test is to determine that the relay contacts dose when the dial is set to ZERO. For this test, the CONTINUITY Light or TONE Signa} of the SR-77 relay tester is used. Consult the manufacturer's instruction leaflet to identify current terminals and contad terminals.

PROCEDURE

l. Connect the SR-77 test set to a suitable source of power as indicated on the nameplate. (NOTE: 15A source can be used if resistance load is not operated above lOA. 60A source is required for full resistance load output. FOR 240V UNITS -7.5A source can be used if resistance load is not operated above lOA. 30A source is required for full resistance load output.) Be sure the controls are OFF. Check the POWER ON light, it should not be glowing.

2. Connect light leads from binding post marked RELA Y CONT ACTS to trip circuit contacts terminals of the relay induction unit.

3. Switch POWER ON/OF Breaker ON. POWER ON Light should glow.

4. Manually rotate time dial on the relay toward ZERO until the CONTINUITY Light glows or TONE Signal sounds. Record reading on time dial.

5. Adjust for any irregularities uncovered and reset time dial as specified.

6. Tu m POWER ON Switch OFF.

PICKUP - INDUCTION UNlT

This test is to determine the mínimum operating current of the relay; that is, the mínimum current needed to close the relay contacts for any particular tap setting.

7. Connect relay induction unit operating coil to the second channel terminals of the Resistance Load Section.

8. Select RESISTANCE LOAD Ammeter range so that relay tap value of current may be read on the upper 1/3 of ammeter scale.

9. Adjust INlTIATE CONTROL Knob to N.O. MAINT., and INITIATE CONTROL Lever to CONT.

10. Turn POWER ON/OFF Breaker ON. POWER ON Light should glow.

11. Initiate unit by pressing INITIATE Switch.

12. Switch appropriate step switches of either channel of the resistance load to increase output until relay picks up and CONTINUITY Light flickers or TONE Signal sounds. The 0-1 amp vernier of either channel may be used for fine adjustment of the outpul.

16 P/N 12442

Rev O

13. Read current on ammeter and record. Adjust if needed.

14. Retum all step switches and vernier controls of RESISTANCE LOAD to OFF position.

TWING TEST - INDUCTJON UNIT

15. Adjust INITIATE CONTROL Knob to N.O. MOM.

16. Select RESISTANCE LOAD Ammeter range so that test current will be read in the upper 113 of meter scale. Use ammeter preset so that ammeter needle is approximately 112 division below desired test current.


18. Set test current desired by holding in INITIA TE Switch and switch proper step switches to increase current, until ammeter needle reads amount of current desired. The 0-1 amp vemiers can be used to malee final current adjustment.

19. Set INITIATE CONTROL Knob to N.O. MAINT. and INITIATE CONTROL Lever to TIMER position.

20. Reset timer to ZERO with RESET Button.

21. Initiate unit by pressing INITIATE Switch. The timer will run and the OUTPUT of the test set will remain energized until the relay contacts close at which time the output will be de-energized and the timer will stop to indicate the elapsed time of the test.

22. Read timer. Time shown is total time of test. Record time.

23. When test is concluded, retum all RESISTANCE LOAD Switches and VERNIER Controls to the OFF position.

TESTING DC TARGET AND SEAL-IN

24. Adjust INITIATE CONTROL Knob to N.O. MAINT. and INITIATE CONTROL Lever to DC position.

25. Select proper range for DC Ammeter with DC A m meter Range Switch.

26. Adjust RESISTANCE LOAD Ammeter so that a current value approximately 50% greater than relay tap value may be read in the upper 113 of the meter scale.

27. Switch RESIST ANCE LOAD Switches to energize relay induction unit operating coil with the value of current approximately 50% greater than relay tap value.

29. When relay induction unit trip circuit contacts close, rotate DC Control clockwise to energize relay target coil with DC. When target drops, read and record DC amperes. Pickup and dropout can be checked by depressing the PUSH TO DROPOUT Push

17 P/N 12442

Rev. O

.. Button.

30. Switch a11 current controls for RESIST ANCE LOAD to the OFF position. If DC circuit remains energized when relay induction unit trip circuit contacts open, the sealin unit is work:ing properly.

31. Return DC Control to ZERO.

TFSTING INSTANT ANEQUS PICKUP USING RESIST ANCE WAD

NOTE: The Resistance Load Section is limited toa maximum of approximately 50 amperes (24 amperes for 240V input). Should more than 50 amperes be required for conducting instantaneous. tests, (24 amperes for 250V input) the Transformer Load Section should be us.ed (refer to the section which covers testing instantaneous pickup with the Transformer Load Section for set up of controls and test procedure).

32. Connect relay instantaneous unit operating coil to the appropriate RESIST ANCE LOAD Output Terminals.

33. Connect relay instantaneous unit trip circuit contacts to RELA Y CONT ACTS Binding Posts of test set.

34. Select RESISTANCE LOAD Ammeter Range so that desired test current will be read in upper 1/3 of meter scale.

35. Set INITIATE CONTROL Knob to N.O. MOM. and INITIATE CONTROL Lever to CONT. position.

36. Initiate unit by depressing and holding the INITIA TE Switch.

37. Switch RESISTAN CE LOAD Switches to increase current until CONTINUITY Light glows or TONE Signal sounds. Malee sure this is mini m u m setting on RESIST ANCE LOAD Switches where instantaneous unit of relay will consistently pick up as the INITIA TE Button is altemately opened and clos.ed. The glowing of the CONTINUITY Light or the alarm signal should be simultaneous with the depression of the INITIA TE Button.

38. Rapidly read this value or current and release INITIA TE Button.

WARNING!! CURRENT IS FWWING THROUGH THE RELA Y COIL UNTIL "INITIA TE" BUTTON IS RELEASED. THEREFORE, IT IS IMPORTANT TO READ V ALUE OF CURRENT RAPIDLY.

39. Read ammeter readings.

40.. After completion of tests, the POWER ON/OFF Breaker should not be switched OFF

18 P/N 12442

Rev.O

until all the heat generated by the resistance load has been dissipated by the cooling fans.

19 P/N 1244~

Rev. O

TESTING INSTANTANEOUS PICKUP OF AN OVERCURRENT RELAY WITH THE TRANSFORMER LOAD

SET UP OF CONTROIS BEFORE TEST RESISTANCE LOAD UNIT

CONTROL

POWER ON/OFF Breaker

INITIA TE CONTROL Knob

INITIA TE CONTROL Lever

TONE/CONTINUITY Switch

DC AMPS Range Switch

DC Control

RESIST ANCE LOAD AMMETER Range Switch

RESISTANCE LOAD CONTROL



POSITION

OFF

N.O. MOM.

CONT.

Either Position

SA

o

SOA

OFF

PARALLEL

NORMAL

TRANSFORMER WAD UNIT

CONTROL POSITION

VOLTMETER SELECTOR Switch EXT.AC

INITIATE BYPASS/NORMAL Switch NORMAL

VOLTAGE RELAY TEST Switch SET NORMAL

EXTERNAL/INTERNAL Switch INTERNAL

VOLTMETER RANGE Switch 300

AUXILIARY SELECTOR Switch VERN.

AUXILIARY OR VERN. Control o

DC 0-150/300V Switch NORMAL

20 P/N 12442 Rev. O

TRANSFORMER LOAD AMMETER Range Switch

Toread test current on upper 1/3 meter scale

TRANSFORMER LOAD Main Control o

0-300 V.A.C./TRANSF. Switch TRANSF.

l. Connect the Model SR-77 to a suitable source of power.

2. Interconnect the Resistance and Transformer Load Sections.

3. Connect relay instantaneous unit operating coil to the appropriate TRANSFORMER LOAD Output Binding Posts.

4. Connect relay instantaneous unit trip circuit contacts to the RELA Y CONT ACTS Binding Posts.

5. Switch POWER ON/OF Breaker ON. POWER ON Light should glow.

6. Initiate unit by depressing and holding in the INITIATE Switch.

7. Ro tate TRANSFORMER LOAD Control clockwise to in crease current until the instantaneous unit pick up. Make sure this is the mínimum setting on the control where the instantaneous unit wilJ consisten ti y pick up as the INITIA TE Switch is altemately opened and closed.

8. Rapidly read this value of current and release INITIA TE Switch.

WARNING!! CURRENT IS FLOWING THROUGH THE RELAY con.., UNTIL INITIA TE SWITCH IS RELEASED. TIIEREFORE, IT IS IMPORTANT TO READ V ALUE OF CURRENT RAPIDLY.

9. Record ammeter reading.

10. Switch test set OFF.

21 P/N 12442

Rev.O

TESTING INDUCTION OVERJUNDER VOLTAGE RELAY Westinehouse Type CV & General Electric IAV

TYPES OF TESTS

Pickup Timing DC Target and Seal

ALWA YS REFER TO THE MANUFACTURER'S LITERA TURE BEFORE TESTING

SET UP OF CONTROLS BEFORE TEST

RESIST ANCE LOAD UNIT

CONTROL

POWER ON/OF Breaker





DC Control

RESIST ANCE LOAD A m meter

RESIST ANCE LOAD CONTROLS Range Switch



22

POSITION

OFF

N.O. MAINT.

CONT.

5A

Either Positinn

o

SOA

OFF

PARALLEL

NORMAL

P/ N 12442 Rcv. O

TRANSFORMER LOAD UNJT

CONTROL POSITION

VOLTMETER SELECTOR Switch V.RELAY

VOLTMETER RANGE Switch So that desired test voltage will be read in upper 1/3 of meter scale

AUXILIARY SELECTOR Switch

IN1TIATE BYPASS/NORMAL Switch

VOLTAGE RELA Y TEST Switch

EXTERNAL/INTERNAL Switch

AUXILIARY OR VERN. Control

DC 0-150/300V Switch


TRANSFORMER LOAD Main Control

0-300 V.A.C./TRANSF.Switch

TESTING FOR PICKUP

V. RELAY

NORMAL

SETNORMAL

INTERNAL

o

NORMAL

250A

o

0-140 V.A.C

l. Connect Model SR-77 toa suitable source of power. Be sure the POWER ON/OF Breaker is OFF.


3. Connect relay operating coil to binding posts marked AUX. AC 24/150/300V on the Transformer Load Section.

4. Connect light leads from binding posts marked RELA Y CONT ACTS to trip circuit contacts terminals of the relay induction unit.

5. Switch POWER ON/OFF Breaker ON. POWER ON Light should glow.

6. Initiate unit by pressing INITIA TE Switch.

7. Rotate TRANSFORMER LOAD Main Control clockwise to increase voltage until CONTINUITY Light flickers or TONE Generator output breaks.

8. Record this value of vo~tage as pickup of the relay.

23 P/N 12442

Rcv. O

TESTING TIMING

9. Rotate TRANSFORMER LOAD Main Control clockwise to increase output until normal relay voltage (see relay nameplate) is observed on voltmeter.

10. Switch INITIATE CONTROL Lever to TIMER position . . , 11. Switch VOLTAGE RELAY TEST Switch to SET FAULT position.

12. Set faulted relay voltage (over or under normal) by rotating AUXILIARY OR VERN. Cont{ol clockwise to increase output. Read voltage on voltmeter.

NOTE: Rotate AUXILIARY Control until voltage read on voltmeter is approximately two volts higher than desired test voltage.

13. Switch VOLTAGE RELAY TEST Switch to TEST position. The fault voltage set in Step 12 will be impressed on the relay operating coil and the digital timer will automatically start.

14. When the relay trip circuit contacts make, the timer will stop to indicate the elapsed time of test.

15. If desired, tum VOLTAGE RELAY TEST Switch back to SET NORMAL. Remove one lead from RELA Y CONTACTS Binding Posts. Reset digital timer. Initiate test set. Replace lead in RELAY CONTACTS Binding Post. Repeat Steps 11 tbrough 14 for other values of fault voltage.

16. Retum all output controls to full counterclockwise position and switch Main ON/OFF Breaker OFF.

TESTING DC TARGEI AND SEAL-IN

17. The OC target and seal-in unit can be tested following the procedure given in the test procedures for testing an overcurrent reJa y.

24 P/N 12442

Rev. O

TESTING PERCENTAGE DIFFERENTIAL RELAYS W estinehouse Type CA & General Electric Type liD

TYPES OF TESTS

Pickup Time Current Characteristic Through Fault Slope



RESISTANCE WAD SECTION

CONTROL


INITIATE CONTROL Knob

INITIATE CONTROL Lever



DC Control

RESISTANCE LOAD AMMETER Range Switch

RESISTANCE LOAD Controls



25

POSITION

OFF

N.O. MOM.

CONT.

Either Position

5A

o

So that desired test can be read in upper 1/3 meter scale

OFF

PARALLEL

NORMAL

PIN 12442 Rev. O

TRANSFORMER WAD SECTION

CONTROL

VOLTMETER SELECTOR Switch

VOLTMETER RANGE Switch


INITIATE BYPASS/NORMAL Switch


AUXILIARY OR VERN. Control


0-300 V.A.C./TRANSF. Switch



TESTING PICKUP

POSITION

EXT.AC

300

VERN.

NORMAL

INfERNAL

o

NORMAL

TRANSF.

o

50 A

l. Connect Model SR-77 toa suitable source of power. Be sure the POWER ON/OFF Breaker is OFF.

2. Interconnect the Resistance and Transformer Load Section.

3. Connect operating coil and one restraint coi] of relay to the Channel Two Terminal of the Resistance Load Section.

4. Connect light leads from binding posts marked RELAY CONTACTS to trip circuit terminals of tbe relay.

NOTE: These relays usually have one moving contact and two flxed contacts. Use terminals for moving contact and one of the fixed contacts.

5. Select RESIST ANCE LOAD AMMETER Range so that expected pickup current will be read in the upper 1/3 of ammeter scale.

6. Turn POWER ON/OFF Breaker ON. POWER ON/OF Breaker ON. POWER ON Light should glow.

7 . Initiate unit by pressing INITIATE Switch.

8. Switch appropriate step switches of either channel of the RESISTANCE LOAD to

26 P/N 12442

Rev O

increase output until relay picks up and CONTINUITY Light flickers or TONE Signal sounds. The 0-1 A verniers of either channel may be used for fine adjustment of the output. Read and record current.

9. Move one light lead to relay terminal for other fixed contact of the relay and repeat Steps 5 through 8.

10. Retum all step switches and vernier controls of RESISTANCE LOAD to OFF position.

TESTING TIME CVRRENT CHARACTERISTICS

NOTE: The Resistance Load Section is limited to approximately 50 amperes maximum. Should more than 50 amperes be required for conducting the Timing Test, the Transformer Load Section may be used.

11 . Select RESISTANCE LOAD AMMETER Range so that desired test current can be read in upper 1/3 of scale. Set ammeter preset mechanism 1/2 division below desired test current. The O- lA verniers of either channel may be used for fme adjustment of the output.

12. Tum POWER ON/OFF Breaker ON. POWER ON Light should glow.

13. Set INITIATE CONTROL Knob to N.O. MAINT. and INlTTATE CONTROL Lever to CONT. position.

14. Set test current by "jogging" with the INITIATE Switch and selecting appropriate step switches of either channel of the RESISTANCE LOAD to increase output until ammeter pointer lifts off of pointer preset to desired test curren t. The 0-1 A verniers of either channel may be used for fine adjustment of the output.

15. Set INITIATE CONTROL Knob to N.O. MAINT. and INITIATE CONTROL Lever to TIMER posi tion.

16. Reset digital timer by depressing Reset Button.

17. Initiate unit by pressing INITIA TE Switch. The timer will run and the output of the test set will remain energized until the relay contacts close at which time the output will be de-energized and the timer will stop to indicate the elapsed time of the test.

18. Read and record time. Time shown is total time of the test.

19. Return al1 step switches and vernier controls of RESISTANCE LOAD to OFF position.

27 P/N 12442

RI!V o

TESTING THROUGH FAULT

20. Connect the restraint coils of the relay to Channel Two Terminals of the Resistance Load Section, so that current flows through them in series.

21. Select proper arnmeter range.

22. Set INITIATE CONTROL Knob to N.O. MOM. and INITIATE CONTROL Lever to CONT. position.



25. Select step switches of Resistance Load Section to increase output to desired value. The 0-1 A vernier may be u sed for fine adjustment of the output. Read current oo ammeter.

26. Manually tum relay disc for evidence of restraint.

27. Retum all step switches and vernier controls of Resistance Load to OFF position.

TESTING SLOPE

NOTE: The Resistance Load Section is limited to approximately 50 amperes maximum. (24 amperes for 240V input). Should more than 50 amperes be required for conducting the Timing Test (24 amperes for 240V input), the Transforrner Load Section may be used.

28. Connect the operating coil to the non-polarity terminal of Channel One and jumper the polarity terminal to the polarity terminal of Channel Two (larger binding post).

29. Connect the restraint terminals of the relay to the output terminal of Channel Two of Resistance Load Section so that current flows through the relay coils in series.

30. Connect light leads form binding posts marked RELA Y CONT ACTS to trip circuil terminals of the relay.

31. Set INITIATE CONTROL Knob to N.O. MAINT. and INITIATE CONTROL Lever to CONT. position.

32. Turn POWER ON/OFF Breaker ON. POWER ON Light should glow.

33. lnitiate unit by pressing INITIATE Switch.

34. Switch appropriate RESISTANCE LOAD Step Switches of Channel Two to increase restraint current to desired value. The O-lA vernier may be used for fine adjustment.

35. Switch appropriate RESISTANCE LOAD Step Switches of Channel One to increase output until CONTINUITY Light flickers or TONE Generator sounds. Tbe O-lA

28 P/ N 124-H

Rev. O

vernier may be used for fine adjustment. Slope of relay is reading of Channe1 Two Ammeter divided by reading of Channel One Ammeter.

36. If desired, the test may be repeated for opposite restraint coil by disconnecting test leads from operating coil terminal and first restraint coil terminal and reconnecting test leads to opposite restraint coil terminal and operating coil terminal.

37. Return ali output controls to OFF position and switch POWER ON/OFF Breaker OFF.

29 PfN 11442

Rev. O

TESTING HARMONIC RESTRAINT DIFFERENTIAL RELA YS Westinehouse Type HU & General Electric Type BDD

TYPES OF TESTS

Pickup of DHR Unit Through Restraint Slope Harmonic Restraint

ALWAYS REFER TO THE MANUFACTQRER'S LITERATURE BEFORE TESTING

The differential unit's pickup test, through restraint test, and slope tests can all be performed following the procedures and set up of controls given in the section of testing of Westinghouse Type CA and General Electric Type UD Relays. The following is the procedure for testing the harmonic restraint element. Only the restraint load section is needed for this test.

SET UP OF CONTROL$ BEFORE TEST

RESIST ANCE LOAD SECTION

CONTROL

POWER ON/OF Breaker

IN1TIATE CONTROL Knob




DC Control





30

POSITION

OFF

N.O. MOM.

CONT.

Either Position

5A

o

So that desired AC current can be read in upper 1/3 meter scale.

OFF

PARALLEL

NORMAL

P/N 12442 R~v O

TESTING HARMONIC RF.STRAINT

l. Connect Model SR-77 toa suitable source of power. Be sure power ON/OFF Breaker is OFF.

2. Switch the SPLIT/PARALLEL Switch to the PARALLEL position.

3. Switch the HARMONIC RESTRAINT Switch to the HARMONIC RESTRAINT position. When in this position, the second harmonic current is obtained at the 0-25A Channel Two Terminals (0-12A for 240 volt input units) .

4. Connect the polarity terminal of Channel Two to the operating coil and the nonpolarity terminal of Channel Two to one of the restraint coils of the relay.

5. Connect light leads from the binding posts marked RELA Y CONT ACT to the trip circuit contacts of the relay so that the pickup of the harmonic restraint element can be monitored.

6. Switch the POWER ON/OFF Breaker ON. POWER ON Light should glow.


8. Switch the first channel RESIST ANCE LOAD Output Step Switches until required half-wave rectified DC current is read on the DC Ammeter. (Only the first four toggle switches are available for this, the other tow switches are tied to Channel Two.)

9. Switch the second RESIST ANCE LOAD Step Switches to increase the AC test current. The O-lA vernier may be used as a fine adjustment. Continue to increase AC current until the harmonic restraint element picks up. Read and record values of AC and DC currents.

11. Retum all output controls to ZERO and repeat Steps 4 through 10 using the other restraint · coil.

12. Retum all output controls to ZERO and switch main POWER ON/OFF Breaker OFF.

31 P/N 12442

Rev. O

TESTING I.T.E. CIRCUIT SHIELD SOLID-STATE OVERCURRENT RELA YS

The following procedure outlines the most efficient manner to consecutively perfonn all tests on an I.T.E. Solid-State Overcurrent Relay. This procedure involves the least possible number of changes in the connecting of test leads and setting of test controls.

TYPES OF TESTS

Pickup - Timing Circuit Time Delay Test Instantaneous Pickup DC Target - Timing Circuit DC Target - Instantaneous Circuit



RESISTIVE LOAD SECTION

CONTROL




CONT/CONTINUITY Switch


DC Control

RESISTIVE LOAD Ammeter Range Switch

RESISTIVE LOAD Controls



32

PQSITION

OFF

N.O. MOM.

Timer

Either Position

5A

O (full counterclockwise)

Toread test current on upper 1/3 meter scale

OFF

PARALLEL

NORMAL

P/N 12442 R~v. O

TRANSFORMER LOAD SECTION

CONTROL

EXTERNALIINTERNAL Switch


VOLTAGE RELAY TEST Switch

VOLTMETER SELECTOR Switch

VOLTMETER RANGE Switch


AUXILIARY OR VERN. CONTROL Knob

DC 0-150/30Y Switch


TRANSFORMER LOAD CONTROL Knob

0-300 V.A.C./TRANSF. LOAD

PICKUP - TIMING CIRCUIT

POSITION

INTERNAL

NORMAL

SET NORMAL

DC

150V

150DC


NORMAL

250A


TRANSF. LOAD

The Pickup Test is conducted to determine the mínimum operating current of the relay for any given tap value.

PROCEDURE

] . Connect the SR -7 test set to a suitable so urce of power as indicated on the nameplate. Be sure the controls are OFF. POWER ON Light should not be glowing.

2. Connect relay input circuit (Relay Terminals 1 - 2, 3 - 4, 5 - 6) to the RESISTIYE LOAD Output Terminals of the test set.

3. Connect light leads from binding post marked TRIP BUS to Terminals 8 and 12.

4. Select RESISTIVE LOAD AC AMMETER Range Switch so that relay tap value of current may be read on the upper 1/3 of the ammeter scale.

5. Connect leads from Red and Black binding posts of the AUX. OUTPUT Section to Terminals 7 and 8, with Black (-) post to Terminal 8. Switch the

33 P/N 12442

R.:v. O

BYPASS/NORMAL Switch to the BYPASS position.

6. Turn POWER ON/OFF Switch ON. Do not inicia te test set at this time.

7. Rotate AUX. CONTROL Knob on Unit 2 until rated DC logic voltage is read on the voltmeter.

8. Reset timer and initiate unit by pressing and holding the INITIATE Switch.

9. Switch the appropriate RESISTIVE LOAD Step switches to increase output until test current on relay is -5% of tap value. The VERNIER Control can be used for fine adjustment.

10. Adjust INITIATE CONTROL Knob to N.O. MAINT. and reset timer.

11. Initiate test set by pressing INITIATE Switch. Relay input circuit will "see" test current. Relay should not operate to de-energize test set under these conditions (allow l 1/2 minutes). De-energize test set by adjusting the INITIATE CONTROL Knob to N.O. MOM. and reset timer.

12. Repeat Steps 6 through 8 above, except test current should be relay tap value +5%.

13. lnitiate test set by pressing INITIATE Switch. Relay input circuü will "see" test current and should operate to de-energize test set and stop timer (allow l 1/2 minutes). Target should operate.

TIME DELA Y AND TARGET TEST


15. Select RESISTIVE LOAD AC Ammeter Range Switch so that desired test current may be read on the upper 113 of ammeter scale.

16. Adjust the AC Ammeter pointer preset mechanism so that the ammeter pointer is approximately two divisions below desired test current.

17. Set desired test current by jogging unit with INITIATE Switch and switch appropriate RESISTIVE LOAD Step Switches to increase output until desired test current is indicated by the ammeter pointer lifting off preset mechanism to the desired curren t. The VERNIER Control Knob may be used for flne adjustment of output current. relea.se INITIATE Switch.

18. Adjust INITIATE CONTROL Knob to N.O. MAINT. Reset timer.

19. Initiate unit by pressing INITIA TE Switch. Timer will run and test current wi 11 be indicated on ammeter. The test set will automatically cut off and the timer will stop when relay's SCR "flres" . Relay target should operate.

INST ANT ANEOUS PICKUP A~lD T ARGET TEST

34 P/N 12442

Rev. O


21 . Relay terminal connections will be the same as for the above tests except Jumper Terminals 9 and 10.

22. Select RESISTIVE LOAD AC Ammeter Range so that desire test current may be read on the upper 1/3 of ammeter scale.

23. Initiate unit by pressing and holding INITIA TE Switch. Switch appropriate RESISTIVE LOAD Step Switches to increase output until test current on relay is -10% of instantaneous setting. (For 0.5-2 ampere tap range, the setting should be-20%.)

24. Release INITIA TE Switch. Reset timer.

25. Press and hold INITIATE Switch. Relay instantaneous circuit should noe pickup to stop timer (allow 0.30 second).

26. Repeat Step 23, except test current should be + 10% of relay instantaneous setting. (For 0.5-2 ampere tap range, the settings should be +20%.)

27. Press and hold INITIATE Switch. Relay instantaneous circuit should pickup and stop the timer. Relay target should operate.

28. Release INITIATE Switch.

WARNING!! CURRENT INDICATED ON AMMETER IS PRESENT IN RELA Y CIRCUIT UNTIL INITIA TE SWITCH IS RELEASED. THEREFORE, IT IS IMPORTANT TO PERFORM THIS TEST AS RAPIDLY AS POSSffiLE TO A VOID OVERHEATING RELA Y.

29. Turn POWER O N/ OFF Breaker off.

35 PIN 12442

Rev. O

TESTING IN SULA TION RESISTANCE


RESISTANCE LOAD SECTION

CONTROL






DC Control





POSITION

OFF

N.O. MOM.

CONT.

Either Position

5A

o

50

OFF

PARALLEL

NORMAL

TRANSFORMER LOAD SECTION

CONTROL POSITION

VOLTMETER SELECTOR Switch I. RES.

VOL TMETER RANGE Switch l. RES.

AUXILIARY SELECTOR Switch l. RES.

INITIA TE BYP ASS/NORMAL Switch NORMAL

VOLT AGE RELA Y TEST Switch SET NORMAL

EXTERNAL/INTERNAL Switch INTERNAL

AUXILIARY OR VERN. Control o

0-300 V.A.C./TRANSF. Switch Either Position

36 P/N 12442

R~v. O

TRANSFORMER LOAD Main Control O

TRANSFORMER LOAD AMMETER 250 Range Switch

TESTING

l. Connect Model SR-77 toa suitable source of power. Be sure the POWER ON/OFF Breaker is OFF.



4. lnitiate unit by depressing INITIATE Switch. The insulation resistance test circuit light should glow.

5. Switch and hold TEST/SET Switch to SET position and rotate AUXILIARY OR VERN. CONTROL to increase output until the voltmeter pointer is aligned with the infinity mark on the meter scale. Release TEST/SET Switch.

6. Connect high voltage test probes to the output terminals and to the relay under test. The relay components will not be harmed as long as one probe is applied to relay frame and the other to all external terminals of the relay.

7. Switch TEST/SET Switch to TEST position. 500 volts DC is now applied to the relay and the insulation resistance can be read on the megohm scale on the voltmeter.

8. Return AUXILIARY OR VERN. Control toO and switch main POWER ON/OFF Breaker OFF.

37 P/N 12+42

Rev. O

TYPE OF TESTS

Pickup Dropout Timing Dropout

TYPICAL TESTS FOR DC AUXILIAR Y RELA YS



RESIST ANCE WAD SECTION

CONTROL






DC Controls





POSITIQN

OFF

N.O. MOM.

CONT.

Either Position

5A

o

50

OFF

PARALLEL

NORMAL

38 PfN 12442

R.:v. O


CONTROL POSITION

VOL TMETER SELECTOR Switch DC

VOL TMETER RANGE Switch So that desired test voltage can be read in upper 1/3 meter scale.




EXTERNAL/INTERNAL Switch



TESTING PICKUP AND DROPOUT

300 DC

NORMAL

SET NORMAL

INTERNAL

NORMAL

250

l. Connect Model SR-77 toa suitable source of power. Make sure POWER ON/OFF Breaker is OFF.


3. Connect relay operating coil terminals to DC 0-150/300V. Output Binding Posts of test set.

4. Connect light leads from test st binding posts marked RELA Y CONT ACTS to trip circuit contact terminals of the relay.


6. Initiate unit by pressing lNITIATE Switch .

7. Rotate AUXILIARY OR VERN. CONTROL clockwise to increase output until CONTTNUTTY Light flickers or TONE Generator sounds.

8. Read pickup voltage on voltmeter. Record.

9. Rotate AUXILIARY OR VERN. CONTROL counterclockwise to decrease output until CONTINUITY Light extinguishes or output from TONE Generator breaks.

10. Read dropout voltage on voltmeter. Record.

TESTING DROPOUT TIME

39 P/N 12442

R <!V o

11. Switch INITIATE CONTROL Knob to N.C. MAINT. and INITIATE CONTROL Lever to TIMER. Output of test ser will de-energize as IN1TIATE CONTROL is adjusted.

12. Put BYPASS/NORMAL Switch in the BYPASS position. Rotate AUX. OUTPUT Control clockwise until rated voltage is applied to relay.

13. Manually close trip circuit contacts so that the DC contacts will pickup and seal-in. Release trip circuit contacts. The contacts should remain picked up.

14. Reset digital timer.

15. Switch DC 0-150/300V Switch to the DROPOUT position. The DC voltage output is switched OFF and the digital timer is automatically started. When the relay's trip circuit contacts break, the digital timer will stop to indicate the dropout time.

16. Return output controls to full counterclockwise position and switch main POWER ON/OFF Breaker OFF.

40 P/N 12442

Rev. O

VOLT AGE RFSTRAINT OVERCURRENT RELA Y

GENERAL

The IJCV contains an induction disc which is influenced by the magnetic fields of two electromagnets. The current actuated electromagnet produces torque on the disc ro close the relay trip circuit contacts and is known as the operating coil. The potentiaJ actuated electromagnet produces torque on the disc to oven the relay trip circuit contacts and is known as the restraint coil. When the voltage applied to the restraint coil decreases, a small amount of current is required to operate the relay and close the trip circuit contacts. This relay may operate to close trip circuit contacts even though the voltage applied to the restraint coil may remain at full system voltage.

The UCV relay is normally used to protect a generator against bus faults.

TFSTING

ALWAYS REFER TO THE MANUFACTIJRER'S LITERATIJRE BEFORE TESTING

TYPE OF TESTS

Pickup of Overcurrent Unit, Zero Voltage Restraint Pickup of Overcurrent Unit, System Voltage Restraint Timing of Overcurrent Unit, Zero Voltage Restraint Timing of Overcurrent Unit, System Voltage Restraint



CONTROL POSITION


INITIATE CONTROL Knob N.O. MOM.

INITIA TE CONTROL Lever CONT.


DC AMPS Range Switch 5A

DC Control o


So that desired test current may be rad in upper 1/3 of meter scale



41

OFF

NORMAL

P/N 12442 Rev. O


CONTROL POSITION

VOLTMETER SELECTOR Switch AUX.AC

VOLTMETER Range Switch So that the desired test voltage is upper 1/3 of meter scale

AUXILIARY SELECTOR Switch 105AC or 300AC (depending on nominal operating voltage of the relay)






TRANSFORMER LOAD Ammeter


0-300 V.A.C/TRANSF. LOAD Switch

NORMAL

NORMAL

INTERNAL

o

NORMAL

250A

o

0-300 V.A.C.

TESTING FOR PICKUP- ZERO VOLTS RESTRAINT

l . Connect Model SR-77 to a suitable source of power in accordance with nameplate. Be sure the POWER ON/OFF Switch is OFF.

2. Interconnect the Control Section to the Auxiliary Section.

3. Connect the relay voltage restraint coil terminals to the White and Yellow binding posts under AUX. AC 0-24/150/300V.

4. Connect the relay current operating coil terminals to the RESIST ANCE LOAD Output Terminal and Common.

5. Connect a set of light leads from the relay trip circuit contact terminals to the test set's binding posts marked RELA Y CONT ACTS.


7. Push the timer reset button and initiate unit by pressing INITIATE Switch.

42 P/N 12442

Rev. O

8. lncrease current through the current operating coil of relay to a value 50% above relay trip setting by switching the appropriate step switches of resistive load. The 0-1 Amp vernier may be used for fine adjustment of output.

9. When relay contacts close, CONTINUITY Light should glow or TONE Generator should sound.

10. Slowly decrease current until CONTINUITY Light flickers or TONE Signal sounds. Record this value of current as PICKUP - zero volts restraint.

11. Retum all step switches of RESISTANCE LOAD to OFF position.

TFSTING FOR PICKUP- SYSTEM VOLTS RESTRAINT

Repeat Steps 1 - 7 above.

8. Apply system voltage to voltage restraint coil of relay by rotating the AUXILIAR Y OR VERN. CONTROL Knob clockwise.

9. Repeat Steps 8-11 above and record as "PICKUP - SYSTEM VOLTS RESTRAINT" .

TESTING TIMING- OVERCVRRENT UNIT- ZERO VOLTS RESTRAINT

l. Connect Model SR-77 to suitable source of power in accordance with nameplate. Be sure the POWER ON/OFF Switch is OFF.

2. lnterconnect the Control Section to the Auxiliary Section.

3. Connect the relay voltage restraint coil terminals to the White and Yellow binding posts under AUX. AC 0-244/ 150/300V.

4. Connect the relay current operating coil terminals to Channel Two of the RESISTIVE LOAD Output Terminal and Common.

5. Connect a set of light leads from the relay trip circuit contact terminals to the test set ' s binding posts marked RELA Y CONT ACTS.

6. Preset Main Ammeter needle 112 division below desired test current.



9. Push the timer reset button and initiate unit by pressing and holding INITIA TE Switch.

1 O. Set test current to desired value by switching the appropriate step switches of resistive load while jogging INITIATE Switch. The 0-1 amp vernier may be used for fme adjustment.

43 P/N 12441

Rev. O

11. Set INITIATE CONTROL Knob to N.O. MAINT. and INITIATE CONTROL lever to TIMER.

12. Reset timer to ZERO by pressing timer reset button.

13. Initiate unit by pressing INITIA TE Switch. Timer will run and test current will flow until the relay trip circuit contacts close.

14. Read timer. Time shown is total time of test. Record time.

15. Tum POWER ON/OFF Breaker OFF.

TF.STING TIMING- OVERCURRENT UNIT- SYSTEM VOLTAGE RESTRAJNT

l. Repeat steps 1 - 9 above.

2. Rotate AUXILIARY OR VERN. CONTROL Knob clockwise to increase voltage until equal to relay system voltage.

3 . Repeat Steps O- 15 above. Record time shown as OVERCURRENT TIMING REST WITH SYSTEM VOLTAGE APPLIED.

44 P/N 12442

Rev. O

GENERAL

VOLTAGE CONTROLLED OVERCURRENT RELAY Westin&house Type COV

The COV Relay contains an induction disc overcurrent unit and an instantaneous undervoltage unit. Tbe undervoltage unit supervises the operation of the overcurrent unit. Regardless of the amount of current passing through the operating coil of the overcurrent unit, no operation takes place unless the undervoltage unit has "dropped out". This means that the overcurrent unit may be set to operate on less than fullload current when the voltage falls below a predetermined value. Conversely, the overcurrent unit will not opera te as long as the voltage is above the predetermined value.

This relay is normally used to protect a generator against a bus fault.

TESIJNG

TYPICAL TESTS

Pickup -Undervoltage Unit Dropout- Undervoltage Unit Voltage Control ·of Overcurrent Unit Pickup - Overcurrent U nit Time Current Characteristics - Overcurrent Unit

ALWAYS REFER TO THE MANVFACTUBER,S LJTERATURE BEFORE TESTING

SET UP OF CONIROLS BEFQRE TEST

RESISTANCE LOAD SECTION

'ONTRQL



INITIATE CONTROL Lever

TONFJCONfiNUITY Switch


DC Control



POSITION

OFF

N.O.MAINT

CONT.

Either Position

5A

o

50 A

PARALLEL

45 P/N 12442

Rev. O

HARMONIC RESTRAINT/ NORMAL Switch

NORMAL


CONTROL

VOL TMETER SELECTOR Switch

VOLTMETER Range Switch

AUXTLIARY SELECTOR Switch

INITIA TE BYP A SS/NORMAL Switch







0-300 V.A.C./TRANSF. LOAD Switch

POSITION

AUX AC

So that desired test voltage will be read in upper 1/3 of meter scale

150 or 300 V.A.C (depending on nominal operating voltage of relay).

NORMAL

NORMAL

INTERNAL

o

NORMAL

250A

o

TRANSF. LOAD

TESTING PICKUP AND DROPOUT OF UNDERVOLTAGE UNIT

l . Connect the SR.:.77 to a suitable source of power as indicated on the nameplate. Be sure the POWER ON/OFF Switch is OFF.

2. Connect the White and Yellow binding posts of the AUX AC 0-24/150/300V to the undervoltage unit operating coil terminals.

3. Connect a pair of light leads from the RELA Y CONTACT Terminal Posts of the test set to the relay undervoltage unit contact terminals.

4. Turn the POWER ON/OFF Breaker ON. The POWER ON Light and the CONTINUITY Light should glow.

5. Press the timer reset button and initiate the test set by pushing the INITIATE Switch.

6. Rotate the AUXILIARY OR VERN. CONTROL Knob clockwise to increase voltage

46 P/N 12442

Rev O

applied to the undervoltage unit operating coil until the CONTINUITY Light just goes out. Read and record this value of voltage as the PICKUP VOLTAGE OF THE UNDERVOLTAGE UNIT.

7 . Continue to rotate AUXTLIARY OR VERN. CONTROL Knob clockwise to increase applied voltage until relay voltage is read on the test set voltmeter.

8. Continue to rotate the AUXILIARY OR VERN. CONTROL Knob counterclockwise to decrease applied voltage until the CONTINUITY Light lights. Read and record this voltage value as the DROPOUT VOLTAGE OF THE UNDERVOLTAGE UNIT.

9. Return AUXILIARY OR VERN. CONTROL Knob to ZERO and turn the POWER ON/OFF Breaker OFF.

TESTING VOLTAGE CONTROL OF OVERCURRENT RELA Y

l. Connect the SR-77 toa suitable source of power as indicated on the nameplate. Be sure the POWER ON/OFF Breaker is OFF.

2. Connect the White and Yellow binding posts of the AUX. AC 0-24/150/300V to the undervoltage unit operating coil terminals.

3. Connect the RESISTANCE LOAD Current Output Terminals of the RESISTANCE LOAD Section to the overcurrent operation coil terminals.

4. Adjust the RESISTANCE LOAD AMMETER Range Switch so that the desüed test current may be read on the upper 113 of the meter scale.

5. Connect a set of light leads from the RELA Y CONTACT Terminals to the relay trip circuit tenninals.

6. Adjust the INJTIA TE CONTROL Lever to the TIMER position.

7. Turn the POWER ON/OFF Breaker ON.

8. Press the timer reset button and initiate the test set by pressing the INITIA TE Switch.

9. Rotate AUXILIARY OR VERN. Knob clockwise until relay rated voltage is read on the voltmeter.

10. Switch the appropriate step switches of the RESISTIVE LOAD until the value of current read on the Main AC Ammeter is approximately four times tap value of the overcurrent unit.

11. The overcurrent unit should nor ooerare to close the relay trip circuit contacts.

12. Rotate the AUX. OR VERN. CONTROL Knob counterclockwise to reduce the voltage until the undervoltage unit drops out.

13. The overcurrent unit should operate to close the relay trip circuit contacts. This will

47 P/N 124-12

Re\ . O

stop the timer and de-energize the test set. There is no need to record the time indicated on the timer, this is not the timing test.

TFSTING PICKUP AND TIMING OF TIIE OVERCURRENT UNIT

1. Insure that the undervoltage contacts are closed before conducting tests.

2. Follow the test procedures for testing an overcurrent relay as on Pages 15 through 19.

48 P/N 12442

Rev. O

OVERCURRENT PHASE BALANCE RELA Y General Electric lJC

The Current Phase Balance Relay operates to tripa circuit breaker when the phase currenls in a circuit become unbalanced by sorne predetermined amount. This relay compares the three phase currents of a line.

GENERAL ELECTRIC TYPE UC

The General Electric IJC Relay is composed of three individual induction disc with two coils per disc. One coil produces a contact closing torque on the disc and is called an operating coil. The second coil produces a contact opening torque on the disc and is called a restraint coil. These two coils see currents from different phases of the circuit and tbe relay will operate when the phase currents become sufficiently unbalanced. The trip circuit contacts associated with al! three induction disc are connected in parallel.

TESTING

ALWAYS REFER TQ MANUFACTURER'S LITERATURE BEFORE TESTING

TYPES OF TESTS

Pickup Timing Slope Target and Seal-In

SET UP OF CONTROlS BEFORE TEST

RESISTANCE LOAD SECTIQN

CONTROL POSITION


INITIA TE CONTROL Knob N.O. MAINT.

INITIATE CONTROL Lever CONT.


DC AMPS Range Switch 5A

DC Control Knob o


So that test current may be read in upper 1/3 of meter scale


49

OFF

P/N 12442 Rev. O



SPLIT

NORMAL


CONTROL POSITION

VOLTMETER SELECTOR Switch EXT.AC

VOLTMETER Range Switch 300

AUXILIARY SELECTOR Switch VERN.

INITIA TE BYPASS/NORMAL Switch NORMAL

VOLTAGE RELA Y TEST Switch NORMAL

VOLTAGE RELA Y TEST Switch NORMAL

EXTERNAUINTERNAL Switch INTERNAL

AUXILIARY OR VERN. Control Knob o

DC 0-150/300V Switch NORMAL

TRANSFORMER LOAD Ammeter 250A

TRANSFORMER LOAD Main Control o

0-300 V.A.C./TRANSF. LOAD Switch TRANSF. LOAD

TESTING PICKUP

l. Connect SR-77 to a suitable source of power as indicated on the nameplate and ground. BE SURE THE MAIN BREAKER IS OFF. CHECK THE POWER ON Light.

2. Connect current operating coil for one unit of the relay to Channel One of the RESIST ANCE LOAD Output Terminals of the test set.



5. Slowly increase current by switching the appropriate step switches of the RESISTANCE LOAD until disc moves and contacts are almost closed. The O-lA vernier may be used for fine adjustment of output. Then decrease current until disc remains stationary at this point.

50 P/N 12442

Rcv O

6. Record this value of ~urrent as pickup.

7. Repeat fo_r operating coils of the other two relay units.

TESTING TIMING

l. Repeat Steps 1 and 2 under Pickup.

2. Set Main Ammeter Pointer Preset to 112 division below desired test current.

3. Adjust INITIATE CONTROL Knob to N.O. MOM. and INITIATE CONTROL Lever to CONT. position.

4. Set test current-desired by jogging with INITIATE Switch and switching appropriate step switches of RESISTANCE LOAD. Fine adjustment may be made by rotating OlA vernier clockwise.

5. Using a pair of light leads, connect relay trip circuit contact terminals to RELAY CONTACTS Binding Posts on the SR-77.

6. Adjust INITIATE CONTROL Knob to N.O. MAINT. and INITIATE CONTROL Lever to .TIMER position.

7. Reset timer. Make sure relay trip circuit contacts are fully open.

8. Initiate test unit by pushing INITIA TE Switch.

9. Observe and record time for relay trip circuit contacts to close.

10. Repeat Steps 1-9 for operating coils of the other two relay units.

TESTING SLOPE

l . Repeat steps 1 and 2 under Pickup Test.

2. Switch SPLIT/PARALLEL Switch to SPLIT position.

3. Connect restraint coil for same relay unit that was used in Step 2 under Pickup Test to the second RESIST ANCE LOAD Output Terminals.

4. Adjust INITIATE CONTROL Knob ~o N.O. MAINT. and INITIATE CONTROL Lever to CONT. position.


6. Initiate unit by pressing INITIA TE Switch.

7 . Switch the appropriate RESIST ANCE LOAD Step Switch es to energize operating coil of relay unit under test.

51 P/ N 12442

Rev. O

8. Switch the appropriate RESIST ANCE LOAD Step Switch es to energize restraint coil of relay unit under test.

9. Regula te the two currents until the disc of the relay under test is stopped with that unit's trip circuit contacts. Use the O-lA vernier controls for fme adjustment. (About halfway between fuU open position and trip position.)

10. Record both values of current and calculate slope. Repeat Steps 1 - 10 for the other relay units.

52 PIN 12442

Rev. O

CURRENT PHASE BALANCE RELA Y Westin2house Type CM

WESTINGHOUSE TYPE CM RELA Y

The Westinghopse Type CM Relay has two individual induction disc. Each disc has two current coils. One coil produces torque to move the disc to the left and the other coil produce$ torqu~ to mo:ve the disc to the right. As long as the currents energizing the two coils are equal,l the torque cancel and the disc remains stati<?nary. In connecting the relay in the circuit, the 1coil producing rotation to the right on one disc is in A Phase, while the coil producing rota, on to the right on one disc is in A Phase, while the coil producing rotation to the left on the San1e disc is in the B Phase. The other disc is connected left rotation B Pbase, right rotation d Phase. Each unit of the relay has a moving contact attacbed to the disc shaft and two statioqary contacts, one on the right and one on the left. When the relay is energized with ibalanced 30 currents, the moving contacts of both relay units should be midway between the left and right stationary contacts. An unbalance of the phase current will cause either or both of the disc to rotate, closing the relay trip circuit contacts, which are connected in p~lel.

TYPES OF 1l5TS Electrical Balai!lce Minimum Tri pi Setting Operating Curve Time Curve

TESTING

ALWAYS REfER TO THE MANVFACTQRER'S LITERATURE BEFQRE TESTING

SET UP OF CONTROL$ BEFORE TEST


CONTROL

POWER ON/<)FF Breaker

INITIATE CONTROL Knob


TONE/CONTtruiTY Switch

DC AMPS Ra.pge Switch

DC Control


53

POS m ON

OFF

N.O. MOM.

CONT.

Either Position

5A

o

So that test current may be read in the upper 113 of meter scale.

PIN 12442 Rev. O




OFF

PARALLEL

NORMAL

TRANSFOBMER WAD SECTION

CONTROL

VOL TMETER SELECTOR Switch

VOLTMETER Range Switch




EXTERNAUINTERNAL Switch





Q-300 V.A.C./TRANSF. LOAD Switch

TESTING ELECTRICAL BALANCE

POSITION

EXT.AC

300

VERN.

NORMAL

NORMAL

INTERNAL

o

NORMAL

250A

o

TRANSF. LOAD

l . Connect Model SR-77 to a suitable source of power as indicated on the nameplate and ground. BE SURE THE MAIN BREAKER IS OFF. CHECK THE POWER ON LIGHT.

2. Connect light leads from RELA Y CONT ACT Binding Posts on test set to the trip circuit contact of the relay.

3. Switch the appropriate step switches of RESISTANCE LOAD to obtain a reading of one ampere on Main Ammeter. Use the O-lA vernier as a flne adjustment control.

4. Adjust left stationary contact until it just makes with the moving contactas indicated by glowing of the CONTINUITY Light.

5. Retum RESISTANCE LOAD Controls to OFF position.

54 P/N 12442

Rev. O

6. Switch the appropriate step switches of RESISTANCE LOAD to obtain a reading of one ampere on second AC Ammeter of test set. Use the O-lA vernier as a fine adjustment control.

7. Adjust right stationary contact until it just makes with moving contact, as indicated by glowing of CONTINUITY Light.

OPERATING CURVE

l . Repeat Steps 1 - 5 under "TESTING ELECTRJCAL BALANCE".

2. Connect light leads from RELA Y CONTACT Binding Posts on the test set to the trip circuit contacts of the relay.

3. Switch the appropriate step switches of the RESISTANCE LOAD until the moving contact and the right stationary contact just make, as indicated by flickering of the CONTINUITY Light. Use the O-lA vernier as a fine adjustment. record readings of both ammeters.

4. Slowly decrease current output of the RESIST ANCE LOAD until the moving contact and left hand stationary contact just make, as indicated by flickering of CONTINUITY Light. Record readings of both ammeters.

Tll\1E CURVE

l. Repeat Steps 1 - 4 under "TESTING ELECTRICAL BALANCE".

2. Connect a pair of light leads from RELA Y CONTACT Binding Posts of the test set to trip circuit contact terminals of the relay.

3. Jog INITIA TE Switch and switch appropriate step switches of RESISTAN CE LOAD to obtain a reading of 10 amperes on Main Ammeter. Use the O-lA vernier as a fine adjustment.

4. Manually set moving contact to BALANCE position.

5. Adjust INITIATE CONTROL Knob to N.O. MAINT. and INITIATE CONTROL Lever to TIMER position.

6. lnitiate test set by pressing INITIATE Switch.

7. Read and record time ·for closure of moving contact and left stationary contact.

8. Adjust INITIATE CONTROL Knob to N.O. MOM. and INITIATE CONTROL Lever to CONT. position.

9. Return INITIATE CONTROL Knob to N.O. MOM. and INITIATE CONTROL Lever to CONT. position.

55 P/N 12442

Rev. O

10. Jog INITIATE Switch and switch the appropriate step switches of RESISTANCE LOAD to obtain a reading of 10 amperes on second AC Ammeter. Use the O-lA vernier as a fine current adjustment.

11. Manually set moving contact to BALANCE position.

12. Adjust INITIATE CONTROL Knob to N.O. MAINT. and INITIATE CONTROL Lever to CONT. position.

13. lnitiate test set by pushing INITIA TE Switch.

14. Read and record time for closure of moving contact and right stationary contact.

Repeat all four tests, i.e., Electrical Balance, Mínimum Trip Setting, Operating Curve and Time Curve for the other induction disc unit.

15. Retum all controls to ZERO and tu m test set OFF.

56 •

P/N 12442 Rev. O

Manual Multi Amp1

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