ABB CW Series Manual

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2.3 Indicating Contactor Switch Unit (ICS)
The dc indicating contactor switch is a small clapper
type 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 contact, 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 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.
3.0 CHARACTERISTICS
Type CW relays are available in the following ranges
and taps:
Typical 60 hertz Time-Power Curves are shown in
Figures 5 and 6. The curves are taken at maximum
torque which occurs with the current leading the volt-
age by 30 degrees. (within ±4°) The time curves
apply ±5% at rated voltage.
3.1 Trip Circuit
The main contacts will safely close 30 Amperes at
250 volts dc and the seal-in contacts of the indicating
contactor switch will safely carry this current long
enough to trip a circuit breaker.
(I
LVLL )
Volts ( 3 single phase watts )
Line-to
Line Range Taps
120 20-120 20- 30- 40- 60- 80- 100- 120
100-600 100- 150- 200- 300- 400- 500- 600
208 35-200 35- 50- 70- 100- 140- 175- 200
175-1000 175- 250- 350- 500- 700- 875- 1000
Figure 1. Time-Power Unit. 2. Indicating Contactor Switch (ICS). Note: Phase shifting resistor is mounted in rear.

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The indicating contactor switch has two taps that
provide pickup setting of 0.2 or 2 Amperes. To
change taps requires connecting the 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 (ICS)
0.2 ampere tap 6.5 ohms dc resistance
2.0 ampere tap 0.15 ohm dc resistance
4.0 INSTALLATION
The relays should be mounted on switch board pan-
els or their equivalent in a location free from dirt,
moisture, excessive vibration and heat. Mount the
relay vertically by means of the four mounting holes
on the flange for semi-flush mounting or by means
of the rear mounting stud or studs for projection
mounting. Either a mounting stud 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 the terminal studs furnished with the
relay for thick panel mounting. The terminal studs
may be easily removed or inserted by locking two
nuts on the stud and then turning the proper nut
with a wrench.
For detailed FT case information refer to I.L. 41-
076.
5.0 SETTINGS
The watt tap, the time dial setting and the ICS tap
must be selected.
5.1 Overwatt Application
The CW for three phase applications has taps which
represents the minimum balanced three phase watts
divided by that will cause the disc to move. Tap
value is also volt-Amperes at which the disc will
begin to move with current leading voltage applied to
the relay by 30 degrees. When connected for watt
sensing, the relay current leads relay voltage by 30
3
Figure 2. Internal Schematic of the Type CW Relay in the
Type FT 11 Case.
Figure 3. Internal Schematic of the Type CW Relay with
SPDT Contacts in Type FT 11 Case.
Figure 4. Current and Voltage Phasors at System Unity
Power Factor Applied to Type CW Relay.
Sub 2
629A173
Sub 1
183A776
Sub 1
849A304
Sub 1
183A776

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Assume:
RC= ct ratio = 600:5 = 120
RV= vt ratio = 4200:120 = 35
P = power = 1000 primary kilowatts
(3Ø)desired trip level
Direct Solution:
T=
Indirect Solution:
IP=
IS= 138.8/120 = 1.157 A secondary
VS= 4160/35 = 118.86 volts line-to-line
T=I
SVS= 1.157 ( 118.86 )=137.5
Use Tap 150 ( closest to 137.5 ) on 100-600 watt relay.
P = 150/137.5 ( 1000 )=1091 kW actual
Time dial 2 will give 2 second operation at 2182 kilowatts.
( See Figure 5. )
P
RCRV3
----------------------- 1 000 000,,
120 35()3
--------------------------- 137.5==
P
3VLL
------------------ 1 000 000,,
34160
---------------------------138.8 A primary==
This allows the motor to be accelerated, and the field
breaker closed before the CW is operative.
Note that the use of field breaker 41a switch control,
prevents loss of field detection on accidental field
breaker opening. Other provisions must be incorpo-
rated to trip the controller when 41a is used and the
field breaker opens following field application. If 41a
is not used directly, it may drive a timer that closes
the coil circuit when 41 closes and has time delay
release when 41 opens.
This same relay will detect loss of synchronism in the
first slip cycle provided the slip frequency is suffi-
ciently low that the CW current stays in the “operate”
area long enough to produce operation.
5.3 ICS Setting
The ICS (indicating contactor switch) has two taps.
The 2.0 ampere tap is used when direct tripping is
used. The 0.2 ampere tap is used with the 125 or 250
volt dc type WL relay switch or equivalent. For the 48
volt dc type WL the 2.0 ampere tap is used.
CAUTION
!
Since the tap block screw carries operating cur-
rent, be sure that the screws are turned tight.
In order to avoid opening current transformer cir-
cuits when changing taps under load, start with
RED handles FIRST and open all switch-
blades.Chassis operating shorting switches on
the case will short the secondary of the current
transformer. The taps may then be changed with
the relay either inside or outside of the case.
Then reclose all switchblades making sure the
RED handles are closed LAST.
degrees when the system current and line-to neutral
voltage are in phase (see Figure 7).
5.2 Motor Loss of Field Application
The usual setting of the CW relay for this application
(Figure 8) is 20 watts, time dial 2 on the 20-120 watt
relay. When, on loss of field, the motor power factor
goes approximately 30 degrees lagging (watts and
vars into the motor) and more, the contacts of the
CW close after the time delay established by the time
dial settings.
In this application, the CW would operate during
motor starting and a field breaker 41a switch may be
used to prevent this by controlling the voltage circuit.
ENERGY REQUIREMENTS
The 60 Hertz burdens of the type CW Relay Three-Phase Application are as follows:
Relay Range Potential Circuit Current Circuit
Current Relay Current
Watts Voltage Volt-Amperes lags by Current Tap Volt-Amperes lags by
20-120 120 17.96 60°5 A 20 16.2 78°
100-600 120 17.96 60°5 A 100 5.4 77°
35-200 208 18.8 59°5 A 35 16.2 78°
175-1000 208 18.8 59°5 A 175 5.4 77°

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6.0 ADJUSTMENT AND MAINTENANCE
The proper adjustments to insure correct operation
of this relay have been made at the factory and
should not be disturbed after receipt by the cus-
tomer. If the adjustments have been changed, the
relay taken apart for repairs, or if it is desired to
check the adjustments at regular maintenance peri-
ods, the instructions below should be followed.
All contacts should be cleaned periodically. a con-
tact burnisher S# 182A836H01 is recommended for
the 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.
6.1 Product Unit
6.1.1 Contacts
The index mark on the movement frame will coin-
cide with the “0”mark on the time dial when the sta-
tionary contact has moved through approximately
one-half of its normal 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
time-current curves.
6.1.2 Minimum Trip Volt Amperes
Connect the relay per Figure 9. Set the time dial to
position 6. Using the lowest tap setting, alternately
apply tap value volt-amperes plus 3% and tap value
volt-amperes minus 3% with the current leading the
voltage by 30°. The moving contact should leave the
backstop at tap value plus 3% and should return to
the backstop at tap value minus 3%. The relay
should be calibrated with 10 times tap value at the
number six time dial position. Check several points
on the typical time curves. Time curve calibration is
affected by adjusting the position of the permanent
magnet keeper. Note that with current leading volt-
age by 30 degrees the actual watts applied to the
relay are.866 time tap value at pickup.
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 indicator target should drop freely.
6.3 Current Coil Ratings:
Continuous 1Sec.
A. 20-120 Watt Range 5 Amperes 230 Amperes
35-200 Watt Range
B. 100-600 Watt Range 8 Amperes 370 Amperes
175-1000 Watt Range
7.0 RENEWAL PARTS
Repair work can be done most satisfactorily at the
factory. However, interchangeable parts can be fur-
nished to the customers who are equipped for doing
repair work. When ordering parts always give the
complete nameplate data.

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Figure 5. Typical 60 Hertz Time Curves of the 20-120 and 35-200 Watt Type CW Relay.
Sub 1
184A600

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Figure 6. Typical 60 Hertz Time Curves of the 100-600 and 175-1000 Watt Type CW Relay.
Sub 1
184A601

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Sub 6
184A811
Figure 7. External Schematic of Three Type CW Relays on a Three-Phase System.
Note: For balanced Three Phase Conditions only one CW Relay is required.
Figure 8. External Schematic of One CW Relay for
Loss of Field Protection.
Figure 9. Diagram of Test Connections for Type CW
Relay in FT 11 Case.
Sub 3
774B831
Sub 3
849A303

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