ABB CO Manual

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.
CAUTION
!1. APPLICATION
The CO Relay is a single phase non-directional
time overcurrent device. It is used to sense current
level above the setting and normally is used to trip
a circuit breaker to clear faults. A wide range of
characteristics permit applications involving coordi-
nation with fuses, reclosers, cold load pickup, motor
starting, or essentially fixed time applications. AC
trip applications are described, but they are not rec-
ommended except in applications where a fault will
not reduce the ac voltage below a level at which
tripping will be reliable.
ABB Power T&D Company Inc.
Power Automation & Protection Division
Coral Springs, FL 33065
Type CO (HI-LO)
Overcurrent Relay
Instruction Leaflet
All possible contingencies which may arise during installation, operation or maintenance, and all details and
variations of this equipment do not purport to be covered by these instructions. If further information is desired
by purchaser regarding this particular installation, operation of maintenance of this equipment, the local Asea
Brown Boveri representative should be contacted.
41-100J
The following describes typical applications of the CO Relay:
RELAY
TYPE TIME CURVE TYPICAL APPLICATIONS
CO-2 Short
1) Differential protection where saturation of current transformers is not ex-
pected, or where delayed tripping is permissible.
2) Overcurrent protection, phase or ground, where coordination with down-
stream devices is not involved and 2 to 60 cycle tripping is allowable.
CO-5 Long Motor locked rotor protection where allowable locked rotor time is
approximately between 10 and 70 seconds.
CO-6 Definite Overcurrent protection where coordination with downstream devices is not involved and CO-2 is too fast. The operating time of this relay does not vary
greatly as current level varies.
CO-7 Moderately Inverse 1) Overcurrent protection where coordination with other divices are re-
quired, and generation varies.
2) Backup protection for relay on other circuits.
CO-8 Inverse
CO-9 Very Inverse
CO-11 Extremely Inverse 1) Motor Protection where allowable locked rotor time is less than 10 sec.
2) Overcurrent protection where coordination with fuses and reclosers is in-
volved, or where cold load pickup or trnsformer inrush are factors.

File No. E103204
Effective : January 1997
Supersedes 41-100I, Dated January 1990
( | ) Denotes Change Since Previous Issue
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I.L 40-100J
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2. CONSTRUCTION AND OPERATION
The type CO relays consist of an overcurrent unit
(CO), either an Indicating Switch (ICS) or an ac Aux-
iliary Switch (ACS) and an Indicating Instantaneous
Trip unit (IIT) when required.
2.1 Electromagnet
The electromagnets for the types CO-5, CO-6, CO-
7, CO-8 and CO-9 relays have a main tapped coil lo-
cated on the center leg of an "E" type laminated
structure that produces a flux which divides and re-
turns 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
cause a contact closing torque.
The electromagnets for the types CO-2 and CO-11
relays have a main coil consisting of a tapped prima-
ry winding and a secondary winding. Two identical
coils on the outer legs of the lamination structure are
connected to the main coil secondary in a manner so
that the combination of all the fluxes produced by the
electromagnet result in out-of-phase fluxes in the air
gap. The out-of-phase air gap fluxes produced
cause a contact closing torque.
2.2 Indicating Contactor Switch Unit (ICS)
The dc indicating contactor switch is a small clapper
type device. A magnetic armature, to which-spring
mounted contacts are attached, is attracted to the
magnetic core upon energization of the switch.
When the switch closes, the moving contacts bridge
two stationary contacts, completing the trip circuit.
Also during this operation two fingers on the arma-
ture deflect a spring located on the front of the
switch, which allows the operation indicator target to
drop.
The front spring, in addition to holding the target,
provides restraint for the armature and thus controls
the pickup value of the switch.
2.3 AC Auxiliary Switch (ACS)
The ac auxiliary switch is a small ac operated clap-
per device. A magnetic armature, to which leaf-
spring mounted contacts are attached, is attracted to
the magnetic core upon energization of the switch.
When the switch closes, the moving contacts bridge
two stationary contacts completing the trip circuit. Al-
so, during the operation, two fingers on the armature
deflect a spring located on the front of the switch
which allows the operation indicator target to drop.
A core screw accessible from the top of the switch
provides the adjustable pickup range.
2.4 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 at-
tracted 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.
A core screw accessible from the top of the switch
and taps on the coil provide the adjustable pickup
range.
3. CHARACTERISTICS
The relays are generally available in the following
current ranges:
These relays may have either single or double circuit
closing contacts for tripping either one or two circuit
breakers. The relays are wired per the internal sche-
matics of Figure 1 to 9.
Thetimevs.currentcharacteristicsareshowninFig-
ures 10 to 16. These characteristics give the contact
closing time for the various time dial settings when
the indicated multiples of tap value current are ap-
plied to the relay.
3.1 Trip Circuit
The main contacts will close 30 amperes at 250 volts
dc and the seal-in contacts of either the indicating
contactor switch or the ac auxiliary switch will carry
this current long enough to trip a circuit breaker.
Range Taps
.5 - 2.5 0.5, 0.6, 0.8, 1.0, 1.5, 2.0, 2.5
1 - 12 1.0, 1.2, 1.5, 2.0, 2.5, 3.0, 3.5,
4.0, 5.0, 6.0, 7.0, 8.0, 10.0, 12.0
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I.L. 41-100J
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The indicating instantaneous trip contacts will close
30 amperes at 250 volts dc and will carry this current
long enough to trip a breaker.
3.2 Indicating Contactor Switch (ICS)
a. The indicating contactor switch has two
taps that provide a pickup setting of 0.2 or 2
amperes.To change taps requires connect-
ing the lead located in front of the tap block
to the desired setting by means of a screw
connection.
b. Trip Circuit Constants
0.2 amperes tap. . . . . . . 6.5 ohms dc
resistance
2.0 amperes tap. . . . . . . 0.15 ohms dc
resistance
3.3 ac Auxiliary Switch (ACS)
a. Each of the following ACS units is available
in the Hi-Lo Line of relays.
4. INSTALLATION
The relays should be mounted on switchboard pan-
els or their equivalent in a location free from dirt,
moisture, excessive vibration and heat. Mount the
relay vertically by means of the mounting stud for
projection mounting or by means of the four mount-
ing holes on the flange for the semiflush mounting.
Energy Requirements
Either the stud or the mounting screws may be uti-
lized for grounding the relay. The electrical connec-
tions may be made directly to the terminals by
means of screws for steel panel mounting or to the
terminal stud furnished with the relay for thick panel
mounting. The terminal stud may be easily removed
or inserted by locking two nuts on the stud and then
turning the proper nut with a wrench.
For detail information on the FT case refer to
I.L. 41-076.
5. SETTINGS
5.1 CO Unit
The overcurrent unit setting can be defined by tap
setting and time dial position or by tap setting and a
specified time of operation at some current multiple
of the tap setting (e.g. 4 tap setting, 2 time dial posi-
tion or 4 tap setting, 0.6 seconds at 6 times tap value
current). The tap setting is the minimum current re-
quired to make the disc move.
To provide selective circuit breaker operation, a min-
imum coordinating time of 0.3 seconds plus circuit
breaker time is recommended between the relay be-
ing set and the relays with which coordination is to
be effected.
The screw on the terminal plate above the time dial
makes connections to various turns on the operating
coil. By placing this screw in the various terminal
plate holes, the relay will respond to multiples of tap
value currents in accordance with the various typical
time-current curves.
Since the tap block screw on both the CO unit
and IIT unit carries operating current, be sure
that the screws are turned tight.
In order to avoid opening current transformer
circuits when changing taps under load, the re-
lay must be first removed from the case. Chassis
operating shorting switches on the case will
short the secondary of the current transformer.
The taps should then be changed with the relay
outside of the case and then re-inserted into the
case.
ACS
UNIT CURRENT RANGE
ASC/VOLTAGE
DROP
RANGE (1)
MINIMUM
RECOMMENDED
SUPPLY
VOLTAGE (2)
0.15
0.5
1.0
0.2-0.38
0.75-1.5
1.5-3.0
40-76
14-27
6.8-14
–
208
120
Notes: (1) This is the voltage range which will operate the ACS coil
only.
(2) When connected as a current switch in series with a full
rated voltage relay or trip coil.
ACS
UNIT
BURDEN IN
VOLT-AMPERES
AT MINIMUM
SETTINGS
THERMAL CAPACITY
AMPERE RATING (COIL)
1 SECOND CONTINUOUS
0.15
0.5
1.0
4.5
4.5
4.5
4.5
18.0
44.0
0.16
0.63
1.60
CAUTION
!
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I.L 40-100J
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5.2 Instantaneous Reclosing
The factory adjustment of the CO unit contacts pro-
vides a contact follow. Where circuit breaker reclos-
ing will be initiated immediately after a trip by the CO
contact, the time of the opening of the contacts
should be a minimum. This condition is obtained by
loosening the stationary contact mounting screw, re-
moving 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 contacts simultaneously with their respective
moving contact.
5.3 Indicating Contactor Switch (ICS)
The only setting required on the ICS unit is the selec-
tion of the 0.2 or 2.0 amperes 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.
When the relay energizes a 125 or 250 volt dc type
WL relay switch, or equivalent, use the 0.2 ampere
tap; for 48 volt dc applications, use the 2.0 ampere
tap and use a type WL relay with a Style
#304C209G01 coil, or equivalent. The relay is
shipped set for 2.0 tap.
5.4 Indicating Instantaneous Trip (IIT)
The IIT setting is the level of ac current at which it will
pickup. It should be set to coordinate with other de-
vices so it will never operate for a fault in a protective
zone where tripping should be produced by other de-
vices. The transient reach will not exceed 130% for
an 80o circuit angle or 108% for a 60o circuit.
The proper tap must be selected and the core screw
must be adjusted to the value of pick-up current de-
sired.
The nameplate data will furnish the actual current
range that may be obtained from the IIT unit. It is rec-
ommended that the IIT be set on the higher tap
where there is a choice of tap settings. For example,,
for a 20 amperes setting use the 20 to 40 tap rather
than the 6 to 20 tap.
5.5 ac Auxiliary Switch (ACS)
The core screw must be adjusted to the value of
pickup current desired.
6. ADJUSTMENTS & MAINTENANCE
The proper adjustments to insure correct operation
of this relay have been made at the factory. Upon re-
ceipt of the relay no customer adjustments, other
than those covered under "SETTINGS" should be
required.
For relays which include an indicating instantaneous
trip unit (IIT), the junction of the induction and indi-
cating instantaneous trip coils is brought out to
switch jaw #3. With this arrangement the overcurrent
units can be tested separately.
Performance Check
The following check is recommended to verify that
the relay is in proper working order:
6.1 Contact
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 normal deflection. Therefore, with the station-
ary contact resting against the backstop, the index
mark is offset to the right of the "0" mark by approxi-
mately .020". The placement of the various time dial
positions in line with the index mark will give operat-
ing times as shown on the respective time-current
curves. For double trip relays, the follow on the sta-
tionary contacts should be approximately 1/32".
6.2 Minimum Trip Current
Set the time dial to position 6 using the lowest tap
setting, alternately apply tap value current plus 3%
and tap value current minus 3%. The moving con-
tacts should leave the backstop at tap value current
plus 3% and should return to the backstop at tap val-
ue current minus 3%.
6.3 Time Curve
Table I 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 I, (e.g. for the CO-8, 2 and 20 times tap value
current) and measure the operating time of the relay.
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I.L. 41-100J
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The .5 to 2.5 amp relay and all CO-2 relays should
be set on the lowest tap. The 1 to 12 amp relay
should be set on the 2 amp tap with the exception of
1-12 amp. CO-2 relay which should be set on 1 amp
tap. The operating times should equal those of Table
I plus or minus 5%.
For type CO-11 relay only, the 1.30 times tap value
operating time from the number 6 time dial position
is 54.9 ±5% seconds and should be checked first. It
is important that the 1.30 times tap value current be
maintained accurately. The maintaining of this cur-
rent accurately is necessary because of the steep-
ness of the slope of the time-current characteristic
(Figure 16). A slight variation, ±1%, in the 1.3 times
tap value current (including measuring instrument
deviation) will change the timing tolerance to ±10%
and the effects of different taps can make the total
variations appear to be ±15%.
6.4 Indicating Instantaneous Trip Unit (IIT)
The core screw which is adjustable from the top of
the trip unit and the tap located on the top of the IIT
determines the pickup value. The trip unit has a
nominal ratio of adjustment of 1 to 24.
The making of the contacts and target indication
should occur at approximately the same instant. Po-
sition 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 oper-
ation indicator target should drop freely.
6.5 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 be not great-
er than the particular ICS tap setting being used. The
operation indicator target drop freely.
The contact follow will be approximately 1/64" to 3/
64". The bridging moving contact should touch both
stationary contacts simultaneously.
6.6 ac Auxiliary Switch (ACS)
The core screw which is adjustable from the top of
the ACS unit determines the pickup value. The mak-
ing of the contacts and target indication should occur
at approximately the same instant. Position the sta-
tionary contact for a minimum of 1/32" wipe. The
bridging moving contact should touch both station-
ary contacts simultaneously.
Apply sufficient current to operate the ACS. The op-
eration indicator target should drop freely.
Routine Maintenance
All relays should be inspected and checked periodi-
cally to assure proper operation. Generally a visual
inspection 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 second-
ary current through the relay and check the time of
operation. It is preferable to make this at several
times pick-up current at an expected operating point
for the particular application. For the .5 to 2.5 am-
peres range CO-5 and CO-6 induction unit use the
alternative test circuit in Fig. 19 as these relays are
affected by a distorted waveform. With this connec-
tion the 25/5 amperes 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 con-
tact burnisher #182A836H01 is recommended for
this purpose.. The use of abrasive material for clean-
ing contacts is not recommended because of the
danger of embedding small particles in the face of
the soft silver and thus impairing the contact.
7. CALIBRATION
Use the following procedure for calibrating the relay
if the relay has been taken apart for repairs or the ad-
justments disturbed. This procedure should not be
used until it is apparent that the relay is not in proper
working order. (See "Performance Check").
CO Unit
7.1 Contact
The index mark on the movement frame will coin-
cide with the "0" mark on the time dial when the
stationary contact has moved through approxi-
mately one-half of its normal deflection. Therefore,
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I.L 40-100J
6
with the stationary contact resting against the back-
stop, 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
time-current curves. For double trip relays, the follow
on the stationary contacts should be approximately
1/32".
7.2 Minimum Trip Current
The adjustment of the spring tension in setting the
minimum trip current value of the relay is most con-
veniently 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 .5-2.5 amp relay and all CO-2 relays on the
minimum tap setting. With the exception of CO-2 re-
lay, set the 1-2 amp relay on the 2 amp tap setting.
Set the 1-12 amp CO-2 on the 1 amp tap. Set time
dial position 6 on all relays.
Adjust the control spring tension no that the moving
contact will leave the backstop at tap value current
+1.0% and will return to the backstop at tap value
current -1.0%.
7.3 Time Curve Calibration
Install the permanent magnet. Apply the indicated
current per Table I for permanent magnet adjust-
ment (e.g. CO-8, 2 times tap value) and measure the
operating time. Adjust the permanent magnet keep-
er until the operating time corresponds to the value
of Table I.
For type CO-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 maintaining of this current accurately is neces-
sary because of the steepness of the slope of the
time-current characteristic (Figure 16). A slight vari-
ation, ±1%, in the 1.3 times tap value current (includ-
ing measuring instrument deviation) will change the
timing tolerance to _ 10% and the effect of different
taps can make the total variations appear to be
±15%. If the operating 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 effect on the minimum pick-up of
the relay. This check is to be made after the 2 times
tap value adjustment has been made.
Apply the indicated current per Table I for the elec-
tromagnet plug adjustment (e.g. CO-8, 20 times tap
value) and measure the operating time. Adjust the
proper plug until the operating time corresponds to
the value in Table I. (Withdrawing the left hand plug,
front view, increases the operation time withdrawing
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.
7.4 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 be not great-
er than the particular ICS tap setting being used. The
operation indicator target should drop freely.
For proper contact adjustment, insert a .030" feeler
guage between the core pin and the armature. Hold
the armature closed against the core pin and guage
and adjust the stationary contacts such that they just
make with the moving contact. Both stationary con-
tacts should make at approximately the same time.
The contact follow will be approximately 1/64" to 3/
64".
7.5 ac Auxiliary Switch (ACS)
The core screw must be adjusted to the value of
pickup current desired. The nameplate data of the
ACS will furnish the actual current range that may be
obtained from the ACS unit.
7.6 Indicating Instantaneous Trip Unit (IIT)
The proper tap must be selected and the core screw
adjusted tothe value of pickup currentdesired.
The nameplate data and tap plate of the IIT will fur-
nish the actual current range that may be obtained
from the IIT unit.
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I.L. 41-100J
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8. RENEWAL PARTS
Repair work can be done most satisfactorily at the
factory. However, interchangeable parts can be
furnished to the customers who are equipped for
doing repair work. When ordering parts always
give the complete nameplate data.
TABLE 1
TIME CURVE CALIBRATION DATA
50 AND 60 Hertz
PERMANENT MAGNET ADJUSTMENT
RELAY
TYPE TIME DIAL
POSITION
CURRENT
(MULTIPLES OF
TAP VALUE)
OPERATING
TIME
SECONDS
CO-2
CO-5
CO-6
CO-7
CO-8
CO-9
CO-11
6
6
6
6
6
6
6
3
2
2
2
2
2
2
0.57
37.80
2.46
4.27
13.35
8..87
11.27
ELECTROMAGNET PLUGS
CO-2
CO-5
CO-6
CO-7
CO-8
CO-9
CO-11
6
6
6
6
6
6
6
20
10
20
20
20
20
20
0.22
14.30
1.19
1.11
1.11
0.65
0.24 ∆
∆For 50 Hz. CO-11 relay 20 times operating time limits are
0.24 + 20% -5%.
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I.L. 41-100J
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ENERGY REQUIREMENTS
INSTANTANEOUS TRIP UN IT(IIT)
60 HERTZ BURDEN (NOTE 1 FOR 50 HZ)
TYPE RANGES AT PICKUP OHMS CONT. 1 SECOND
OF AVAILABLE TAP MINIUM 3 10 20 RATING RATING
IIT WITH CORE SETTING PICKUP R XL Z TIMES TIMES TIMES AMPS AMPS
UNIT ADJUSTMENT PICKUP PICKUP PICKUP
2-7 2-7 2 .68 .42 .8 .72 .67 .67 2.5 70
2-48 7-14 7-14 7 .076 .048 .09 .086 .075 .075 7 140
14-48 14-48 14 .032 .012 .035 .035 .035 .035 10 185
6-20 6-20 6 108 .067 .127 .125 .125 .100 7 88
6-144 20-40 20-40 20 .016 .008 .018 .018 .018 .018 16 280
40-144 40-144 40 .007 .002 .007 .007 .007 .007 25 460
NOTE 1. 50 Hz values for Z and OHMS are 96% to 100% of 60 Hz Values.
CO-2 SHORT TIME RELAY
60 HERTZ VOLT AMPERES**(x∆FOR 50 HZ)
AMPERE CONTINUOUS ONE SECOND POWER
RANGE TAP RATING RATING FACTOR
(AMPERES) (AMPERES) ANGLE ø
0.5 0.91 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
0.5/2.5 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 73.6 700 285
1.0 1.65 28 55 4.6 37.3 266 895
1.2 1.90 28 54 4.6 38.0 280 1000
1.5 2.20 28 53 4.8 40.0 310 1150
2.0 3.30 28 54 4.8 40.5 315 1180
2.5 4.00 56 56 4.7 39.2 282 970
3.0 5.00 56 55 4.9 40.2 295 1050
3.5 5.50 56 54 4.9 41.0 312 1125
1/12 4.0 6.50 56 53 4.8 41.0 325 1150
5.0 7.10 230 53 5.1 42.7 330 1200
6.0 8.80 230 50 5.2 44.0 360 1350
7.0 9.50 230 48 5.7 48.5 390 1600
8.0 10.50 230 46 6.2 53.0 475 1800
10.0 12.00 230 40 6.8 61.0 565 2500
12.0 13.00 230 35 7.8 0 680 3300
AT AT 3 TIMES AT 10 TIMES AT 20 TIMES
TAP VALUE TAP VALUE TAP VALUE TAP VALUE
CURRENT CURRENT CURRENT CURRENT
(∆= 0.86) (∆= 0.88) (∆= 0.9) (∆= 0.91)
Thermal capacities for short times other than one second may be calculated on the basis of times being inversely proportional to the
square of the current
øDegrees current lags voltage at tap value current
** Voltages taken with Rector type voltmeter
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ENERGY REQUIREMENTS
CO-5 LONG TIME AND CO-6 DEFINITE MINIMUM TIME RELAYS
60 HERTZ VOLT AMPERES**(x∆FOR 50 HZ)
RANGE TAP RATING RATING FACTOR
(AMPERES) (AMPERES) ANGLE ø
0.5 2.7 88 69 3.93 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
0.5/2.5 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
1.0 4.5 88 69 3.98 21.0 100 265
1.2 5.5 88 68 3.98 21.3 103 282
1.5 6.0 88 67 4.00 21.8 109 308
2.0 7.7 88 66 3.98 21.9 115 340
2.5 9.5 88 65 3.98 22.2 122 363
3.0 10.0 230 65 4.02 22.5 125 366
1/12 3.5 12.0 230 65 4.06 23.2 132 402
4.0 13.5 230 64 4.12 23.5 137 420
5.0 15.0 230 61 4.18 24.6 150 500
6.0 17.5 460 60 4.35 25.8 165 570
7.0 20.5 460 57 4.44 27.0 185 630
8.0 22.5 460 53 4.54 28.6 211 736
10.0 23.5 460 48 4.80 32.5 266 940
12.0 26.5 460 42 5.34 37.9 325 1152
CO-7 MODERATELY INVERSE TIME RELAY
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
0.5/2.5 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
1.0 4.5 88 68 3.86 20.6 100 265
1.2 5.5 88 67 3.82 20.4 104 270
1.5 6.0 88 66 3.92 21.2 110 300
2.0 7.7 88 65 3.90 21.8 117 312
2.5 9.5 88 64 3.90 21.8 123 360
3.0 10.0 230 63 3.92 22.5 127 390
1/12 3.5 12.0 230 63 3.97 22.7 131 413
4.0 13.5 230 63 4.02 22.9 136 420
5.0 15.0 230 60 4.11 24.1 153 490
6.0 17.5 460 58 4.29 25.5 165 528
7.0 20.5 460 54 4.43 27.3 189 630
8.0 22.5 460 50 4.50 30.8 206 732
10.0 23.5 460 46 4.81 32.6 250 970
12.0 26.5 460 42 5.04 36.9 342 1224
AT AT 3 TIMES AT 10 TIMES AT 20 TIMES
TAP VALUE TAP VALUE TAP VALUE TAP VALUE
CURRENT CURRENT CURRENT CURRENT
(∆= 0.86) (∆= 0.88) (∆= 0.9) (∆= 0.91)
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.
øDegrees current lags voltage at tap value current
* * Voltages taken with Tectox type voltmeter
Courtesy of NationalSwitchgear.com

I.L. 41-100J
11
ENERGY REQUIREMENTS
CO-8 INVERSE TIME AND CO-9 VERY INVERSE TIME RELAYS
60 HERTZ VOLT AMPERES**(x∆FOR 50 HZ)
AMPERE CONTINUOUS ONE SECOND POWER
RANGE TAP RATING RATING FACTOR
(AMPERES) (AMPERES) (AMPERES)
0.5 2.7 88 72 3.38 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
0.5/2.5 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
1.0 4.5 88 73 2.33 20 135 347
1.2 5.5 88 73 2.33 20 135 361
1.5 6.0 88 72 2.35 20.1 142 383
2.0 7.7 88 69 2.35 20.2 145 412
2.5 9.5 88 68 2.36 20.3 146 415
3.0 10.0 230 67 2.37 20.4 149 420
1/12 3.5 12.0 230 66 2.38 20.9 153 450
4.0 13.5 230 65 2.40 21.0 157 460
5.0 15.0 230 63 2.40 21.0 164 500
6.0 17.5 460 60 2.47 21.6 170 525
7.0 20.5 460 57 2.51 21.8 180 600
8.0 22.5 460 55 2.52 22.2 192 672
10.0 23.5 460 48 2.77 24.5 230 830
12.0 26.5 460 45 2.94 25.4 258 960
CO-11 EXTREMELY INVERSE TIME RELAY
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
0.5/2.5 1.0 2.5 56 27 0.89 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
1.0 3.5 56 30 0.82 7.4 82 300
1.2 4.0 56 29 0.90 8.0 87 324
1.5 5.5 56 26 0.97 8.6 93 350
2.0 8.5 56 25 1.00 8.9 96 380
2.5 10.0 56 24 1.10 9.0 96 377
3.0 12.5 230 33 0.87 8.0 88 340
1/12 3.5 14.0 230 31 0.88 8.2 88 340
4.0 15.0 230 29 0.94 8.7 96 366
5.0 17.0 230 25 1.10 10.0 110 435
6.0 18.5 460 22 1.25 11.5 120 478
7.0 20.0 460 20 1.40 12.3 135 560
8.0 21.5 460 19 1.50 14.0 160 648
10.0 25.0 460 14 1.9 18.3 210 900
12.0 28.0 460 10 2.4 23.8 276 120
AT AT 3 TIMES AT 10 TIMES AT 20 TIMES
TAP VALUE TAP VALUE TAP VALUE TAP VALUE
CURRENT CURRENT CURRENT CURRENT
(∆= 0.86) (∆= 0.88) (∆= 0.9) (∆= 0.91)
Thermal capacities for short times other than one second may be calculated on the basis of times being inversely proportional to
the square of the current
øDegrees current lags voltage at tap value current
* * Voltages taken with Rector type voltmeter
Courtesy of NationalSwitchgear.com

I.L 40-100J
12
Figure 1. Internal Schematic of the Double Trip Relay Without IIT
Sub 3
57D4524
ICS
INDICATING
CONTACTOR
SWITCH
INDUCTION UNIT
RED HANDLE
TEST SWITCH
CURRENT TEST JACK
CHASSIS OPERATED
SHORTING SWITCH
TERMINAL
Courtesy of NationalSwitchgear.com

I.L. 41-100J
13
Figure 2. Internal Schematic of the Double Trip Relay With IIT
Sub 1
3498A03
Courtesy of NationalSwitchgear.com

I.L 40-100J
14
Figure 3. Internal Schematic of the Single Trip Relay Without IIT
Sub 3
57D4523
Courtesy of NationalSwitchgear.com

I.L. 41-100J
15
Figure 4. Internal Schematic of the Single Trip Relay With IIT
Sub 1
3498A02
Courtesy of NationalSwitchgear.com

I.L 40-100J
16
Figure 5. Internal Schematic of Double Trip Relay With ITT to Separate Terminals
Sub 1
3508A73
Courtesy of NationalSwitchgear.com

I.L. 41-100J
17
Figure 6. Internal Schematic of the Single Trip Relay With ITT Contacts Wired to Two Separate Terminals
Sub 2
3516A07
Courtesy of NationalSwitchgear.com

I.L 40-100J
18
Figure 7. Internal Schematic of the Single Trip Relay With an ACS Unit
Sub 6
183A608
Courtesy of NationalSwitchgear.com

I.L. 41-100J
19
Figure 8. Internal Schematic of the Single Trip Relay With an ACS Unit and IIT
Sub 4
3515A06
Courtesy of NationalSwitchgear.com

I.L 40-100J
20
Figure 9. Internal Schematic of the Single Trip Relay With an ACS Unit and with IIT Contacts
Sub 1
3524A37
Wired to Two Separate Terminals
Courtesy of NationalSwitchgear.com