Types CR, CRC, CRP and CRDDirectional Overcurrent Relays

All possible contingencies which may arise during installation, operation or maintenance, and all details and vari-

ations of this equipment do not purport to be covered by this instructions. If further informaitonis desired by pur-

chaser regarding this particular installation, operation or maintenance of this equipment, the local ABB Inc.

representative should be contacted.

Instruction LeafletInstruction Leaflet

ABB

CONTENTS

This instruction leaflet applies to the following

types of relays:

• Type CR Voltage Polarized Phase Relay

• Type CRC Current Polarized Ground Relay

• Type CRP Voltage Polarized Ground Relay

• Type CRD Dual Polarized Ground Relay

CAUTION

Before putting relays into service, remove all

blocking which may have been inserted for the

purpose of securing the parts during shipment,

make sure that all moving parts operate freely,

inspect the contacts to see that they are clean

and close properly, and operate the relay to

check the settings and electrical connections.

1.0 APPLICATION

These time delayed directional overcurrent relays are

used to detect phase or ground faults in a particular

direction on a power system and to initiate isolation of

these faults. Each is torque-controlled by a built-in

high speed directional unit.

The CR is a phase relay with a directional unit polar-

ized by phase to phase voltage while the CRC, CRP

and CRD are ground relays. The CRC directional unit

is zero-sequence-current polarized, the CRP is

zero-sequence-voltage polarized and the CRD con-

tains two directional units, one zero-sequence-cur-

rent polarized and another zero-sequence-voltage

polarized.

The choice of the CRC or CRP is dependent on the

reliability of the zero-sequence polarizing current or

voltage for all ground faults with all power system vari-

ations. Where neither alone is generally reliable for all

ground faults, but one or the other is always present

for ground faults, the dual polarized CRD is used.

2.0 CONSTRUCTION AND OPERATION

The various types of relays as outlined in the contents

consists of a directional unit or units, an overcurrent

unit, an indicating contactor switch unit, and an indi-

cating instantaneous trip unit when required. The type

CRP and type CRD relays also utilize an internal

phase shifting mechanism. The principal component

parts of the relay and their location are shown in Fig-

ures 1 and 2, page 9; Figures 3 and 4, page 10.

2.1 Overcurrent Unit (CO)

The overcurrent unit operates on the induction princi-

ple. A main tapped coil located on the center leg of an

“E” type laminated structure produces a flux which di-

vides and returns through the outer legs. A shading

coil causes the flux through the left leg to lag the main

pole flux. The out-of-phase fluxes thus produced in

the air gap causes a contact closing torque.

Effective: June 1998

Supersedes I.L. 41-131P, dated August 1986

( | ) Denotes change since previous issue

41-131Q

Types CR, CRC, CRP and CRD

Directional Overcurrent Relays

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

2.2 Indicating Contactor Switch Unit (ICS)

The indicating contactor switch is a small dc operated

clapper type device. A magnetic armature, to which

leaf-spring mounted contacts are attached, is attract-

ed to the magnetic core upon energization of the

switch. When the switch closes, the moving contacts

bridge two stationary contacts, completing the trip cir-

cuit. Also during this operation two fingers on the ar-

mature deflect a spring located on the front of the

switch, which allows the operation indicator target to

drop. The target is reset from the outside of the case

by a push rod located at the bottom of the cover.

The front spring, in addition to holding the target, pro-

vides restraint for the armature and thus controls the

pickup value of the switch.

2.3 Indicating Instantaneous Trip Unit (IIT)

The instantaneous trip unit is a small ac operated

clapper type device. A magnetic armature, to which

leaf-spring mounted contacts are attached, is attract-

ed to the magnetic core upon energization of the

switch. When the switch closes, the moving contacts

bridge two stationary contacts completing the trip cir-

cuit. Also during the operation two fingers on the ar-

mature deflect a spring located on the front of the

switch which allows the operation indicator target to

drop. The target is reset from the outside of the case

by a push rod located at the bottom of the cover.

A core screw accessible from the top of the switch

provides the adjustable pickup range.

2.4 Directional Unit (D)

The directional unit is a product induction cylinder

type unit operating on the interaction between the po-

larizing circuit flux and the operating circuit flux.

Mechanically, the directional unit is composed of four

basic components: a die-cast aluminum frame, an

electromagnet, a moving element assembly, and a

molded bridge.

The frame serves as the mounting structure for the

magnetic core. The magnetic core which houses the

lower pin bearing is secured to the frame by a locking

nut. The bearing can be replaced, if necessary, with-

out having to remove the magnetic core from the

frame.

The electromagnet has two series-connected polariz-

ing coils mounted diametrically opposite one another;

two series-connected operating coils mounted dia-

metrically opposite one another; two magnetic adjust-

ing plugs; upper and lower adjusting plug clips, and

two locating pins. The locating pins are used to accu-

rately position the lower pin bearing, which is mount-

ed on the frame, with respect to the upper pin bearing,

which is threaded into the bridge. The electromagnet

is secured to the frame by four mounting screws.

The moving element assembly consists of a spiral

spring, contact carrying member, and an aluminum

cylinder assembled to a molded hub which holds the

shaft. The shaft has removable top and bottom jewel

bearings. The shaft rides between the bottom pin

bearing and the upper pin bearing with the cylinder ro-

tating in an air gap formed by the electromagnet and

the magnetic core. The stops for the moving element

contact arm are an integral part of the bridge.

The bridge is secured to the electromagnet and frame

by two mounting screws. In addition to holding the up-

per pin bearing, the bridge is used for mounting the

adjustable stationary contact housing. The stationary

contact housing is held in position by a spring type

clamp. The spring adjuster is located on the under-

side of the bridge and is attached to the moving arm

by a spiral spring. The spring adjuster 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 to

the spring adjuster clamp.

The contacts of the directional unit are connected in

series with the shading coil of the overcurrent unit.

This arrangement prevents the relay from operating

for faults in the non-tripping direction.

3.0 CHARACTERISTICS

The time characteristics of the directional overcurrent

relays are designated by specific numbers as indicat-

ed in Table 1, page 3 (e.g. CR-8).

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

The relays are generally available in the following

overcurrent unit current ranges:

These relays may have either single or double circuit

closing contacts for tripping either one or two circuit

breakers.

The time vs. current characteristics are shown in Fig-

ures 17 to 23 (starting on page 23). These character-

istics give the contact closing time for the various time

dial settings when the indicated multiples of tap value

current are applied to the relay.

3.1 Trip Circuit

The main contacts will safely close 30 amperes at 250

volts dc and the seal-in contacts of the indicating con-

tactor switch will safely carry this current long enough

to trip a circuit breaker.

The indicating instantaneous trip contacts will safely

close 30 amperes at 250 volts dc, and will carry this

current long enough to trip a breaker.

The indicating contactor switch has two taps that pro-

vide a pickup setting of 0.2 or 2 amperes. To change

taps requires connecting of lead located in front of the

tap block to the desired setting by means of a screw

connection.

3.2 Trip Circuit Constants

Indicating Contactor Switch

0.2 amp tap. . . . . . . . 6.5 ohms dc resistance

2.0 amp tap. . . . . . . . 0.15 ohms dc resistance

3.3 Type CR Relay

This voltage polarized type relay is intended for phase

fault protection and the directional unit has its maxi-

mum torque when the current leads the voltage by ap-

proximately 30°. The directional unit minimum pickup

is 1 volt and 4 amperes at its maximum torque angle

for the 4 and 12 ampere range relays and 1 volt and 2

amperes for the 2 to 6 ampere and 0.5 to 2.5 ampere

range relays.

The directional unit should be connected using the

current in one phase wire and the potential across the

other two phase wires. This connection is commonly

referred to as the 90

connection. When utilizing the

connection the maximum torque of the relay oc-

curs when the fault current lags its 100% P.F. position

by approximately 60

. (See Figure 13, page 21.)

3.4 Type CRC Relay

The current polarized type relay is intended for

ground fault protection and operates on residual cur-

rent. (See Figure 15, page 22.) The type CRC relay

has its maximum torque when the operating current

leads the polarizing current by approximately 40

. The

directional unit minimum pickup is 0.5 ampere in each

winding in phase for the 0.5 to 2.5 ampere and the 2

to 6 ampere range relays.

3.5 Type CRP Relay

The voltage polarized relay is intended for ground

fault protection and has its maximum torque when the

current lags the voltage by approximately 60

. The

shifting of the maximum torque angle has been ac-

complished by the use of an internally mounted phase

shifter as illustrated in Figure 7 (page 17).

The type CRP relay operates on residual voltage and

residual current. (See Figure 14, page 21).

The directional unit minimum pickup is 1 volt and 2

amperes at its maximum torque angle for the 0.5 to

2.5 ampere and the 2 to 6 ampere range relays.

TABLE 1:

Time Characteristics Designation

Short Time 2

Long Time 5

Definite Time 6

Moderately Inverse Time 7

Inverse Time 8

Very Inverse Time 9

Extremely Inverse Time 11

Range Taps

0.5 - 2.5 0.5 0.6 0.8 1.0 1.5 2.0 2.5

2 - 6 2 2.5 3 3.5 4 5 6

4 - 12 456781012

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

3.6 Type CRD Relay

The dual polarized type relay is intended for ground

fault protection. The relay can be polarized from a po-

tential source, from a local ground source, or from

both simultaneously.

The type CRD relay utilizes the directional unit of the

CRC relay in conjunction with the directional unit and

phase shifting mechanism of the type CRP relay. The

directional contacts are connected in parallel to

torque-control a common overcurrent unit. See Figure

8 (page 17).

The current-polarized directional unit of the type CRD

relay operates on residual currents while the potential

polarized directional unit of the type CRD relay oper-

ates on residual voltage and residual current. See

Figure 16 (page 22).

For the 0.5 to 2.5 ampere and the 2 to 6 ampere range

relays, the minimum pickup of the current polarized

unit is 0.5 ampere in each winding in-phase and the

minimum pickup for the voltage polarized unit is 1 volt

and 2 amperes with the current lagging voltage by

4.0 SETTINGS

4.1 Overcurrent Unit (CO)

The overcurrent unit settings can be defined either by

tap settings and time dial position or by tap setting

and a specific time of operation at some current

multiple of the tap setting (e.g. 4 tap setting, 2 time

dial position or 4 tap setting, 0.6 times tap value cur-

rent).

To provide selective circuit breaker operation, a mini-

mum coordinating time of 0.3 seconds plus breaker

time is recommended between the relay being set

and the relays with which coordination is to be affect-

ed.

The connector screw on the terminal plate above the

time dial makes connection to various turns on the op-

erating coil. By placing the screw in the various termi-

nal plate holes, the relay will respond to multiples of

tap value currents in accordance with the various typ-

ical time-current curves.

CAUTION

Since the tap block screws carry operating

current, be sure that the screws are turned

tight.

In order to avoid opening current transformer

circuits when changing taps under load, start

with RED handles FIRST and open all

switchblades. Chassis operating shorting

switches on the case will short the secondary

of the current transformer. Taps may then be

changed with the relay either inside or out-

side the case. Then reclose all switchblades

making sure the RED handles are closed

LAST.

4.2 Instantaneous Reclosing

The factory adjustment of the CO unit contacts pro-

vides a contact follow. Where circuit breaker reclosing

will be initiated immediately after a trip by the CO con-

tact, the time of the opening of the contacts should be

a minimum. This condition is obtained by loosening

the stationary contact mounting screw, removing the

contact plate and then replacing the plate with the

bent end resting against the contact spring.

For double trip relays, the upper stationary contact is

adjusted such that the contact spring rests solidly

against the back stop. The lower stationary contact is

then adjusted such that both stationary contacts

make contact simultaneously with their respective

moving contact.

4.3 Indicating Contactor Switch (ICS)

The only setting required on the ICS unit is the selec-

tion of the 0.2 or 2.0 ampere tap setting. This selec-

tion is made by connecting the lead located in front of

the tap block to the desired setting by means of the

connecting screw.

4.4 Indicating Instantaneous Trip (IIT)

The core screw must be adjusted to the value of

pickup desired.

The nameplate data will furnish the actual current

range that may be obtained from IIT unit.

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

4.5 Directional Unit (D)

No setting is required.

5.0 INSTALLATION

The relays should be mounted on switchboard panels

or their equivalent in a location free from dirt, mois-

ture, excessive vibration and heat. Mount the relay

vertically by means of the two mounting studs for the

type FT projection case or by means of the four

mounting holes on the flange for the semi-flush type

FT case. Either of the studs or the mounting screws

may be utilized for grounding the relay. The electrical

connections may be made directly to the terminals by

means of screws for steel panel mounting or to termi-

nal studs furnished with the relay for thick panel

mounting. The terminal studs may be easily removed

or inserted by locking two nuts on the studs and then

turning the proper nut with a wrench.

The external ac connections of the directional over-

current relays are shown in Figures 13 to 16 (starting

on page 21).

6.0 ADJUSTMENTS

The proper adjustments to insure correct operation of

this relay have been made at the factory. Upon receipt

of the relay, no customer adjustments, other than

those covered under “SETTINGS” (page 4), should

be required.

For relays which include an indicating instantaneous

trip unit (IIT), the junction of the induction and indicat-

ing instantaneous trip coils is brought out to switch

jaw #3. With this arrangement the overcurrent units

can be tested separately.

The following acceptance check is recommended to

insure that the relay is in proper working order:

6.1 Acceptance Check

6.1.1 Overcurrent Unit (CO)

The directional unit contacts must be in the closed po-

sition when checking the operation of the overcurrent

unit.

6.1.2 Contact

a) By turning the time dial, move the moving contacts

until they deflect the stationary contact to a position

where the stationary contact is resting against its

backstop. The index mark located on the move-

ment frame should coincide with the “0” mark on

the time dial. For double trip relays, the follow on

the stationary contacts should be approximately

1/64”.

b) For relays identified with a “T”, located at lower left

of stationary contact block, the index mark on the

movement frame will coincide with the “0” mark on

the time dial when the stationary contact has

moved through approximately one-half of its nor-

mal deflection. Therefore, with the stationary

contact resting against the backstop, the index

mark is offset to the right of the “0” mark by

approximately .020". The placement of the various

time dial positions in line with the index mark will

give operating times shown on the respective

time-current curves. For double trip relays, the fol-

low on the stationary contacts should be

approximately 1/32”.

6.1.3 Minimum Trip Current

Set the time dial to position 6. Alternately apply tap

value current plus 3% and tap value current minus

3%. The moving contact should leave the backstop at

tap value current plus 3% and should return to the

backstop at tap value current minus 3%.

6.1.4 Time Curve

Table 2 (page 11) shows the time curve calibration

points for the various types of relays. With the time

dial set to the indicated position, apply the currents

specified by Table 2 (e.g. for the CR-8, 2 and 20 times

tap value current) and measure the operating time of

the relay. The operating times should equal those of

Table 2 plus or minus 5 percent.

For type CR-11 relay only, the 1.30 times tap value

operating time from the number 6 time dial position is

54.9 ±5% seconds. It is important that the 1.30 times

tap value current be maintained accurately. The main-

taining of this current accurately is necessary be-

cause of the steepness of the slope of the time-cur-

rent characteristics (Figure 23, page 29). A 1%

variation in the 1.30 times tap value current (including

measuring instrument deviation) will change the nom-

inal operating time by approximately 4%.

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

6.2 Indicating Contactor Switch (ICS)

Close the main relay contacts and pass sufficient dc

current through the trip circuit to close the contacts of

the ICS. This value of current should not be greater

than the particular ICS tap setting being used. The in-

dicator target should drop freely.

The contact follow should be approximately 1/64” to

3/64”. The bridging moving contacts should touch

both stationary contacts simultaneously.

6.3 Indicating Instantaneous Trip Unit (IIT)

The core screw must be adjusted to the value of

pickup current desired.

The nameplate data will furnish the actual current

range that may be obtained from the IIT unit.

6.4 Directional Unit (D)

6.4.1 Contact Gap

The gap between the stationary contact and moving

contact with the relay in a de-energized position

should be approximate ly.020".

6.4.2 Sensitivity

The respective directional units should trip with value

of energization and phase angle relationships as indi-

cated in Table 3 (page 11).

6.4.3 Spurious Torque Adjustments

There should be no spurious closing torques when

the operating circuits are energized, per Table 4

(page 12), with the polarizing circuits short-circuited

for the voltage polarized units and open-circuited for

the current polarized units.

7.0 ROUTINE MAINTENANCE

All relays should be inspected and checked periodi-

cally to assure proper operation. Generally a visual in-

spection should call attention to any noticeable

changes. A minimum suggested check on the relay

system is to close the contacts manually to assure

that the breaker trips and the target drops. Then re-

lease the contacts and observe that the reset is

smooth and positive.

If an additional time check is desired, pass secondary

current through the relay and check the time of oper-

ation. It is preferable to make this at several times

pickup current at an expected operating point for the

particular application. For the .5 to 2.5 ampere rating

CO-5 and CO-6 induction unit use the alternative test

circuit in Figure 24 (page 30) as these relays are af-

fected by a distorted wave form. With this connection

the 25/5 ampere current transformers should be

worked well below the knee of the saturation (i.e., use

10L50 or better).

All contacts should be periodically cleaned. A contact

burnisher, Style number 182A836H01, is recom-

mended for this purpose. The use of abrasive material

for cleaning contacts is not recommended, because

of the danger of embedding small particles in the face

of the soft silver and thus impairing the contact.

8.0 CALIBRATION

Use the following procedure for calibrating the relay if

the relay has been taken apart for repairs or adjust-

ments have been disturbed. This procedure should

not be used unless it is apparent that the relay is not

in proper working order. (See “ACCEPTANCE

CHECK”, page 5).

8.1 Overcurrent Unit (CO)

8.1.1 Contact

a) By turning the time dial, move the moving contacts

until they deflect the stationary contact to a position

where the stationary contact is resting against its

backstop. The index mark located on the move-

ment frame should coincide with the “0” mark on

the time dial. For double trip relays, the follow on

the stationary contacts should be approximately

1/64”.

b) For relays identified with a “T”, located at lower left

of stationary contact block, the index mark on the

movement frame will coincide with the “0” mark on

the time dial when the stationary contact has

moved through approximately one-half of its nor-

mal deflection. Therefore, with the stationary

contact resting against the backstop, the index

mark is offset to the right of the “0” mark by

approximately .020". The placement of the various

time dial positions in line with the index mark will

give operating times as shown on the respective

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

time-current curves. For double trip relays, the fol-

low on the stationary contacts should be

approximately 1/32”.

8.2 Minimum Trip Current

The adjustment of the spring tension in setting the

minimum trip current value of the relay is most conve-

niently made with the damping magnet removed.

With the time dial set on “0”, wind up the spiral spring

by means of the spring adjuster until approximately

6-3/4 convolutions show.

Set the relay on the minimum tap setting, the time dial

to position 6.

Adjust the control spring tension so that the moving

contact will leave the backstop at tap value current

plus 1.0% and will return to the backstop at tap value

current minus 1.0%.

8.3 Time Curve Calibration

Install the permanent magnet. Apply the indicated

current (per Table 2, page 11) for the permanent mag-

net adjustment (e.g. CR-8, 2 times tap value) and

measure the operating time. Adjust the permanent

magnet keeper until the operating time corresponds

to the value of Table 2.

For type CR-11 relay only, the 1.30 times tap value

operating time from the number 6 time dial position is

54.9 ±5% seconds. It is important that the 1.30 times

tap value current be maintained accurately. The main-

taining of this current accurately is necessary be-

cause of the steepness of the slope of the time-cur-

rent characteristic (Figure 23, page 29). A 1%

variation in the 1.30 times tap value current (including

measuring instrument deviation) will change the nom-

inal operating time by approximately 4%. If the oper-

ating time at 1.3 times tap value is not within these

limits, a minor adjustment of the control spring will

give the correct operating time without any undue ef-

fect on the minimum pickup of the relay. This check is

to be made after the 2 times tap value adjustment has

been completed.

Apply the indicated current per Table 2 of the electro-

magnet plug adjustment (e.g. CR-8, 20 times tap val-

ue) and measure the operating time. Adjust the prop-

er plug until the operating time corresponds to the

value in Table 2. (Withdrawing the left-hand plug,

front view, increases the operating time and withdraw-

ing the right hand plug, front view, decreases the

time.) In adjusting the plugs, one plug should be

screwed in completely and the other plug run in or out

until the proper operating time has been obtained.

Recheck the permanent magnet adjustment. If the

operating time for this calibration point has changed,

readjust the permanent magnet and then recheck the

electromagnet plug adjustment.

8.4 Indicating Contactor Switch Unit (ICS)

Close the main relay contacts and pass sufficient dc

current through the trip circuit to close the contacts of

the ICS. This value of current should not be greater

than the particular ICS tap setting being used. The in-

dicator target should drop freely.

8.5 Indicating Instantaneous Trip Unit (IIT)

The core screw which is adjustable from the top of the

trip unit determines the pickup value. The trip unit has

a normal ratio of adjustment of 1 to 4 and an accuracy

within the limits of 10%.

The making of the contacts and target indication

should occur at approximately the same instant. Posi-

tion the stationary contact for a minimum of 1/32”

wipe. The bridging moving contact should touch both

stationary contacts simultaneously.

Apply sufficient current to operate the IIT. The indica-

tor target should drop freely.

8.6 Directional Unit (D)

a. The upper pin bearing should be screwed down

until there is approximately .025" clearance be-

tween it and the top of shaft bearing. The upper pin

bearing should then be securely locked in position

with the lock nut. The lower bearing position is

fixed and cannot be adjusted.

b. The contact gap adjustment for the directional unit

is made as follows:

With the moving contact in the normally-opened

position, i.e. against the right stop on bridge, screw

in the stationary contact until both contacts just

close as indicated by a neon lamp in the contact

circuit. Then, screw the stationary contact away

from the moving contact 3/4 of a turn. The clamp

holding the stationary contact housing need not be

loosened for the adjustment since the clamp utiliz-

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

es a spring-type action in holding the stationary

contact in position.

The set screw in the stationary contacts has been

factory adjusted for optimum follow and this adjust-

ment should not be disturbed.

The moving contact assembly has been factory

adjusted for low contact bounce performance and

should not be disturbed.

c. The sensitivity adjustment is made by varying the

tension of the spiral spring attached to the moving

element assembly. The spring is adjusted by plac-

ing a screwdriver or similar tool into one of the

notches located on the periphery of the spring ad-

juster and rotating it. The spring adjuster is located

on the underside of the bridge and is held in place

by a spring-type clamp that does not have to be

loosened prior to making the necessary adjust-

ments.

The spring is to be adjusted such that the contacts

will close as indicated by a neon lamp in the con-

tact circuit when energized with the required

current and voltage as shown in Table 3 on page

11. This table indicates that the spring can be ad-

justed when the phase angle relationship between

the operating circuit and the polarizing circuit is at

the maximum torque angle or when the circuit rela-

tionship has the operating and polarizing circuits in

phase. It is recommended that a single phase

(in-phase relationship) setup be used as a matter

of ease and convenience.

4. The magnetic plugs are used to reverse any un-

wanted spurious torques that may be present

when the relay is energized on current alone.

The reversing of the spurious torques is accom-

plished by using the adjusting plugs in the following

manner:

a) Voltage circuit terminals on the voltage polar-

ized relays (CR, CRP and CRD voltage

polarized unit) are short-circuited.

b) The polarizing circuit of the current polarized

relays (CRC and CRD current polarized unit)

are open-circuited.

Upon completion of either “a” or “b” apply currents

from 5 to 40 amps or 5 to 80 amps.

Note: High current to be applied only momentarily.

Plug adjustment is then made per Table 4 (see page

12) such that the spurious torques are reversed. The

plugs are held in position by upper and lower plug

clips. These clips need not be disturbed in any man-

ner when making the necessary adjustment.

The magnetic plug adjustment may be utilized to pos-

itively close the contacts on current alone. This may

be desired on some installations in order to insure

that the relay will always trip the breaker on zero

potential.

9.0 RENEWAL PARTS

Repair work can be done most satisfactorily at the

factory. However, interchangeable parts can be fur-

nished to customers who are equipped for doing

repair work. When ordering parts, always give the

complete nameplate data.

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 1: Type CR Relay Without Case

#1 – Directional Unit (D)

#2 – Overcurrent Unit (CO)

#3 – Indicating Contactor Switch (ICS)

#4– Indicating Instantaneous Trip Unit IIIT)

Figure 2: Directional Unit

#1 – Stationary Contact #2 – Stationary Contact Pressure

Spring

#3 – Magnetic Adjusting Plugs #4 – Upper Bearing Screw

#5 – Moving Element Assembly #6 – Spring Adjuster Clamp

#7 – Current Bias Vane

Photo

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 3: Time Overcurrent Unit (Front View)

1-Tap Block 2-Time Dial 3-Control Spring Assembly

4-Disc 5-Stationary Contact Assembly 6-Magnetic Plugs

7-Permanent Magnet.

Figure 4: Indicating Instantaneous Trip Unit (IIT)

Photo

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

TABLE 2:

TIME CURVE CALIBRATION DATA - 50 AND 60 HERTZ FOR OVERCURRENT UNIT

PERMANENT

MAGNET ADJUSTMENT

ELECTROMAGNET

PLUG ADJUSTMENT

RELAY

TYPE

TIME

DIAL

POSITION

CURRENT

(MULTIPLES OF

TAP VA LUE)

OPERATING

TIME

(SECONDS)

CURRENT

(MULTIPLES OF

TAP VALUE)

OPERATING

TIME

(SECONDS)

0.57

37.80

2.46

4.27

13.35

8.87

11.27

0.22

14.30

1.19

1.11

0.65

0.24

* For 50 Herz CO-11, the “20 times multiple” Time Limits are 0.24 sec. +20% -5%.

TABLE 3:

DIRECTIONAL UNIT SENSITIVITY

RELAY TYPE

SETTING RANGE

OF TIME -

OVERCURRENT

UNIT

Values for Min. Pick-Up

* The energization quantities are input quantities at the relay terminals.

Volts

†

† For relays rated 240 volts, apply 2 volts.

Amperes Phase Angle Relationship

0.5 - 2.5

2 - 6

12.0

I Leading V by 30°

‡

‡ Maximum torque angle.

1 2.3 I in-phase with V

4 - 12

14.0

I Leading V by 30°

‡

1 4.6 I in-phase with V

CRP

0.5 - 2.5

2 - 6

12.0

I lagging V by 60°

‡

1 4.0 I in-phase with V

4 - 12

14.0

I Leading V by 60°

‡

1 4.6 I in-phase with V

CRC

0.5-2.5

2-6

0.5 I in-phase

CRD (Voltage Unit)

05-2.5

2-6

2.0

I Lagging V by 60°

‡

4.0 I in-phase with V

4-12 1

4.0

I Lagging V by 60°

‡

8.0 I in-phase with V

CRD (Current Unit)

0.5-2.5

2-6

0.5 in-phase

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

TABLE 4:

DIRECTIONAL UNIT CALIBRATION

SETTING

RANGE OF

TIME–

OVERCURRENT

UNIT

CURRENT

AMPERES

CONDITION FOR BOTH PLUGS “IN” ADJUSTMENT

0.5 - 2.5 Amps

2 - 6 Amps

5 to 40

Spurious Torque in contact closing

direction (left front view)

Right (front-view) plug screwed out

until spurious torque is reversed.

4 - 12 Amps 5 to 80

0.5 - 2.5 Amps

2 - 6 Amps

5 to 40 Spurious Torque in contact opening

direction (right front view, contacts

remain open)

Left (front view) plug screwed out until

Spurious Torque is in contact closing

direction. Then the plug is screwed in

until spurious Torque is reversed.

4 - 12 Amps 5 to 80

DIRECTIONAL UNIT POLARIZING CIRCUIT BURDEN

Relay

Type Rating

Volt

Amperes

* Voltages taken with high impedance type voltmeter - Burden of Voltage polarized units taken at 120 volts - Bur-

den of current polarized units taken at 5 amperes.

Power

Factor

Angle

†

† Degrees current leads or lags voltage at 120 volts on voltage polarized units and 5 amperes on current polar-

ized units.

132

‡

Volts

‡ Continuous rating.

11.5 58° Lag

CRC

230

Amperes

** One second rating.

1.45 8° Lag

CRP

208

††

Volts

†† 30 second rating.

11.2 28° Lead

CRD

Current Unit

230 ** Amperes 1.45 8° Lag

CRD

Voltage Unit

208

††

Volts

11.2 28° Lead

DIRECTIONAL UNIT OPERATING CIRCUIT BURDEN

Relay

Type

Range

(Amperes)

Continuous

Rating

(Amperes)

One Second

Rating

(Amperes)

* Thermal capacities for short times other than one second may be calculated on the basis of time being inversely propor-

tional to the square of the current.

Power

Factor

Angle

†

Degrees current lags voltage at tap value current

VOLT AMPERES

‡

‡ Voltages taken with high impedance type voltmeter.

Minimum

Tap Value

Current

3 Times

Minimum

Tap Value

Current

At 10 Times

Minimum

Tap Value

Current

At 20 Times

Minimum

Tap Value

Current

2-6 10 230 34.5 0.44 4.08 48.0 182.0

4-12 12 280 25.0 0.53 5.0 59.2 236.0

CRC

0.5-2.5 - 230 44.0 0.033 0.30 3.3 14.2

2-6 - 230 42.5 0.58 5.28 58.0 240.0

CRP

0.5-2.5 10 230 34.5 0.03 0.23 2.8 11.5

2-6 10 230 34.5 0.44 4.08 48.0 182.0

CRD

0.5-2.5 10 230 45.0 0.07 0.59 6.6 26.0

2-6 10 230 45.0 1.04 9.9 106.0 420.0

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

ENERGY REQUIREMENTS

OVERCURRENT UNITS = CR-2, CRC-2, CRP-2 CRD-2

AMPERE

RANGE TAP

CONTINUOUS

RATING

(AMPERES)

ONE SECOND

RATING

(AMPERES)

* 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.

POWER

FACTOR

ANGLE

†

† Degrees current lags voltage at tap value current.

VOLT AMPERES

‡

‡ Voltages taken with high impedance type voltmeter.

TAP VALUE

CURRENT

AT 3 TIMES

TAP VALUE

CURRENT

AT 10 TIMES

TAP VALUE

CURRENT

AT 20 TIMES

TAP VALUE

CURRENT

0.5/2.5

0.5 .91 28 58 4.8 39.6 256 790

0.6 0.96 28 57 4.9 39.8 270 851

0.8 1.18 28 53 5.0 42.7 308 1024

1.0 1.37 28 50 5.3 45.4 348 1220

1.5 1.95 28 40 6.2 54.4 435 1740

2.0 2.24 28 36 7.2 65.4 580 2280

2.5 2.50 28 29 7.9 73.6 700 2850

2/6

2.0 3.1 110 59 5.04 38.7 262 800

2.5 4.0 110 55 5.13 39.8 280 920

3.0 4.4 110 51 5.37 42.8 312 1008

3.5 4.8 110 47 5.53 44.0 329 1120

4.0 5.2 110 45 5.72 46.0 360 1216

5.0 5.6 110 41 5.90 50.3 420 1500

6.0 6.0 110 37 6.54 54.9 474 1800

4/12

4.0 7.3 230 65 4.92 39.1 268 848

5.0 8.0 230 50 5.20 42.0 305 1020

6.0 8.8 230 47 5.34 44.1 330 1128

7.0 9.6 230 46 5.53 45.8 364 1260

8.0 10.4 230 43 5.86 49.9 400 1408

10.0 11.2 230 37 6.60 55.5 470 1720

12.0 12.0 230 34 7.00 62.3 528 2064

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

ENERGY REQUIREMENTS

OVERCURRENT UNITS = CR-5, CRC-5, CRP-5, CRD-5, CR-6, CRC-6, CRP-6, CRD-6

OVERCURRENT UNITS = CR-7, CRC-7, CRP-7, CRD-7

VOLT AMPERES

‡

AMPERE

RANGE TAP

CONTINUOUS

RATING

AMPERES

ONE SECOND

RATING *

AMPERES

POWER

FACTOR

ANGLE

†

TAP VALUE

CURRENT

AT 3 TIMES

TAP VALUE

CURRENT

AT 10 TIMES

TAP VALUE

CURRENT

AT 20 TIMES

TAP VALUE

CURRENT

0.5/2.5

0.5 2.7 88 69 3.92 20.6 103 270

0.6 3.1 88 68 3.96 20.7 106 288

0.8 3.7 88 67 3.96 21 114 325

1.0 4.1 88 66 4.07 21.4 122 360

1.5 5.7 88 62 4.19 23.2 147 462

2.0 6.8 88 60 4.30 24.9 168 548

2.5 7.7 88 58 4.37 26.2 180 630

2/6

2 8 230 67 3.88 21 110 308

2.5 8.8 230 66 3.90 21.6 118 342

3 9.7 230 64 3.93 22.1 126 381

3.5 10.4 230 63 4.09 23.1 136 417

4 11.2 230 62 4.12 23.5 144 448

5 12.5 230 59 4.20 24.8 162 540

6 13.7 230 57 4.38 26.5 183 624

4/12

4 16 460 65 4.00 22.4 126 376

5 18.8 460 63 4.15 23.7 143 450

6 19.3 460 61 4.32 25.3 162 531

7 20.8 460 59 4.35 26.4 183 611

8 22.5 460 56 4.40 27.8 204 699

10 25 460 53 4.60 30.1 247 880

12 28 460 47 4.92 35.6 288 1056

AMPERE

RANGE TAP

CONTINUOUS

RATING

AMPERES

ONE SECOND

RATING

AMPERES

* 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.

POWER

FACTOR

ANGLE

†

† Degrees current lags voltage at tap value current.

VOLT AMPERES

‡

‡ Voltages taken with high impedance type voltmeter.

TAP VALUE

CURRENT

AT 3 TIMES

TAP VALUE

CURRENT

AT 10 TIMES

TAP VALUE

CURRENT

AT 20 TIMES

TAP VALUE

CURRENT

0.5/2.5

0.5 2.7 88 68 3.88 20.7 103 278

0.6 3.1 88 67 3.93 20.9 107 288

0.8 3.7 88 66 3.93 21.1 114 320

1.0 4.1 88 64 4.00 21.6 122 356

1.5 5.7 88 61 4.08 22.9 148 459

2.0 6.8 88 58 4.24 24.8 174 552

2.5 7.7 88 56 4.38 25.9 185 640

2/6

2 8 230 66 4.06 21.3 111 306

2.5 8.8 230 63 4.07 21.8 120 342

3 9.7 230 63 4.14 22.5 129 366

3.5 10.4 230 62 4.34 23.4 141 413

4 11.2 230 61 4.34 23.8 149 448

5 12.5 230 59 4.40 25.2 163 530

6 13.7 230 58 4.62 27 183 624

4/12

4 16 460 64 4.24 22.8 129 392

5 18.8 460 61 4.30 24.2 149 460

6 19.3 460 60 4.62 25.9 168 540

7 20.8 460 58 4.69 27.3 187 626

8 22.5 460 55 4.80 29.8 211 688

10 25 460 51 5.20 33 260 860

12 28 460 46 5.40 37.5 308 1032

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

ENERGY REQUIREMENTS

OVERCURRENT UNITS = CR-8, CRC-8, CRP-8, CRD-8 and CR-9, CRC-9 CRP-9 CRD-9

OVERCURRENT UNITS = CR-11, CRC-11, CRP-11 CRD-11

AMPERE

RANGE TAP

CONTINUOUS

RATING

AMPERES

ONE SECOND

RATING

AMPERES

POWER

FACTOR

ANGLE

†

VOLT AMPERES

††

TAP VALUE

CURRENT

AT 3 TIMES

TAP VALUE

CURRENT

AT 10 TIMES

TAP VALUE

CURRENT

AT 20 TIMES

TAP VALUE

CURRENT

0.5/2.5

0.5 2.7 88 72 2.38 21 132 350

0.6 3.1 88 71 2.38 21 134 365

0.8 3.7 88 69 2.40 21.1 142 400

1.0 4.1 88 67 2.42 21.2 150 440

1.5 5.7 88 62 2.51 22 170 530

2.0 6.8 88 57 2.65 23.5 200 675

2.5 7.7 88 53 2.74 24.8 228 800

2/6

2 8 230 70 2.38 21 136 360

2.5 8.8 230 66 2.40 21.1 142 395

3 9.7 230 64 2.42 21.5 149 430

3.5 10.4 230 62 2.48 22 157 470

4 11.2 230 60 2.53 22.7 164 500

5 12.5 230 58 2.64 24 180 580

6 13.7 230 56 2.75 25.2 198 660

4/12

4 16 460 68 2.38 21.3 146 420

5 18.8 460 63 2.46 21.8 158 480

6 19.3 460 60 2.54 22.6 172 550

7 20.8 460 57 2.62 23.6 190 620

8 22.5 460 54 2.73 24.8 207 700

10 25 460 48 3.00 27.8 248 850

12 28 460 45 3.46 31.4 292 1020

AMPERE

RANGE TAP

CONTINUOUS

RATING

AMPERES

ONE SECOND

RATING

AMPERES

* 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.

POWER

FACTOR

ANGLE

†

† Degrees current lags voltage at tap value current.

VOLT AMPERES

‡

‡ Voltages taken with high impedance type voltmeter.

TAP VALUE

CURRENT

AT 3 TIMES

TAP VALUE

CURRENT

AT 10 TIMES

TAP VALUE

CURRENT

AT 20 TIMES

TAP VALUE

CURRENT

0.5/2.5

0.5 1.7 56 36 0.72 6.54 71.8 250

0.6 1.9 56 34 0.75 6.80 75.0 267

0.8 2.2 56 30 0.81 7.46 84.0 298

1.0 2.5 56 27 1.89 8.30 93.1 330

1.5 3.0 56 22 1.13 10.04 115.5 411

2.0 3.5 56 17 1.30 11.95 136.3 502

2.5 3.8 56 16 1.48 13.95 160.0 610

2/6

3.0 7.0 230 32 0.73 6.30 74.0 264

2.5 7.8 230 30 0.78 7.00 78.5 285

2.0 8.3 230 27 0.83 7.74 84.0 309

3.5 9.0 230 24 0.88 8.20 89.0 340

4.0 10.0 230 23 0.96 9.12 102.0 372

5.0 11.0 230 20 1.07 9.80 109.0 430

6.0 12.0 230 20 1.23 11.34 129.0 504

4/12

4.0 14 460 29 0.79 7.08 78.4 296

5.0 16 460 25 0.89 8.00 90.0 340

6.0 17 460 22 1.02 9.18 101.4 378

7.0 18 460 20 1.10 10.00 110.0 454

8.0 20 460 18 1.23 11.1 124.8 480

10.0 22 460 17 1.32 14.9 131.6 600

12.0 26 460 16 1.8 16.3 180.0 720

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 5: Internal Schematic of double-trip, directional overcurrent relay

type CR in type FT-21 Case. For the single-trip relay the circuits

associated with terminal 2 are omitted, 57D4549

Figure 6: Internal Schematic of double-trip, directional overcurrent relay

type CRC in type FT-21 Case. For the single -rip relay the circuits

associated with terminal 2 are omitted, 57D4539

Sub 2

57D4547

Sub 3

57D4543

RED HANDLE

TEST SWITCH

CURRENT TEST JACK

CHASSIS OPERATED

SHORTING SWITCH

TERMINAL

INDICATING

CONTACTOR SWITCH

DIRECTIONAL UNIT

INDUCTION UNIT

INTRNAL SCHEMATIC

INDICATING

CONTACTOR SWITCH

DIRECTIONAL UNIT

INDUCTION UNIT

RED HANDLE

TEST SWITCH

CURRENT TEST JACK

CHASSIS OPERATED

SHORTING SWITCH

TERMINAL

WITH RELATIVE INSTANTANEOUS

POLARITY AS SHOWN THE

DIRECTIONAL UNIT CONTACTS CLOSE

WITH RELATIVE INSTANTANEOUS

POLARITY AS SHOWN THE

DIRECTIONAL UNIT CONTACTS CLOSE

INTRNAL SCHEMATIC

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 7: Internal Schematic of double-trip, directional overcurrent relay

type CRP in type FT-21 Case. For the single-trip relay the circuits

associated with terminal 2 are omitted, 57D4545

Figure 8: Internal Schematic of double-trip, directional overcurrent relay

type CRD in type FT-21 Case. For the single-trip relay the

circuits associated with terminal 2 are omitted, 57D4561

Sub 2

57D4541

Sub 3

57D4559

INDUCTION UNIT

RED HANDLE

TEST SWITCH

CURRENT TEST JACK

CHASSIS OPERATED

SHORTING SWITCH

TERMINAL

DIRECTIONAL

UNIT

INDICATING

CONTACTOR

SWITCH

CHASSIS OPERATED

SHORTING SWITCH

RED HANDLE

TEST SWITCH

CURRNT TEST JACK

TERMINAL

UPPER DIRECTIONAL

UNIT

LOWER DIRECTIONAL

UNIT

INDUCTION UNIT

INDICATING

CONTACTOR SWITCH

WITH RELATIVE

INSTANTANEOUS

POLARITY AS SHOWN

THE DIRECTINAL UNIT

CONTACTS CLOSE

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 9A: Internal schematic of single-trip, directional control relay type CR

with indicating instantaneous trip unit, and ICS unit having two

independent contacts, in type FT-21 case

Figure 9B: Internal schematic of single-trip directional control relay type CR

with indicating instantaneous trip unit, in Type FT-21 case

Sub 1

9657A31

Sub 6

57D4520

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 10A: Internal schematic of single-trip directional control relay type CR

with indicating instantaneous trip unit and ac shunt trip, in type

FT-21 case

Sub 5

57D4540

Figure 10B: Internal Schematic of single-trip directional control relay type CRC

with Indicating Instantaneous Trip Unit, in type FT21 case

Sub 2

3507A69

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 11: Internal schematic of single-trip directional control relay type CRP

with indicating instantaneous trip unit, in type FT-21 case

Figure 12: Internal schematic of single-trip directional control relay type CRD

with indicating instantaneous trip unit, in type FT-31 case

*Sub 6

57D4546

Sub 5

57D4560

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Sub 2

182A793

Figure 13: External schematic of the type CR relay for phase fault protection Figure 14: External schematic of the type CRP relay for ground fault

protection

* Sub 3

182A792

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 15: External schematic of the type CRC relay for ground fault

protection

Sub 3

182A790

Figure 16: External schematic of the type CRD relay for ground fault

protection

Sub 5

182A791

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 17: Typical time curves for relays with CO-2 units

Sub 1

Curve 619584

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 18: Typical time curves for relays with CO-5 units

Sub 2

Curve 418245

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 19: Typical time curves for relays with CO-6 units

Sub 3

Curve 418246

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 20: Typical time curves for relays with CO-7 units

Sub 3

Curve 418247

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 21: Typical time curves for relays with CO-8 units

Sub 3

Curve 418248

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 22: Typical time curves for relays with CO-9 units

Sub 2

Curve 418249

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 23: Typical time curves for relays with CO-11 units

Sub 2

Curve 288B655

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 24: Diagram of test connections of the overcurrent units

Sub 2

182A873

41-131Q

Directional Overcurrent Relays

Types CR, CRC, CRP & CRD

Figure 25: Outline and drilling plan for the type CR, CRC and CRP relays in the type FT-21 case

* Denotes Change Since Previous Issue

* Sub 17

57D7901