ABB CWC Instruction Leaflet page 4

41-242.2F
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.
2.4 INDICATING INSTANTANEOUS TRIP UNIT
(IIT)
The instantaneous trip is a small a-c operated clap-
per 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 contacts completing the trip circuit.
Also 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.
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. The minimum
and maximum pickup points are indicated on the
scale, which is located to the rear of the core screw.
4
Type CWC and CWP Directional Ground Relay
3.0 OPERATION AND
CHARACTERISTICS
The operating torque for the CWC relay is obtained
by energizing the lower pole coil with residual current
(usually obtained from the line current transformer)
and the 2 tapped upper pole coils with residual cur-
rent from the current transformer in the power bank
neutral, For the CWP relay the operating torque is
obtained by energizing the upper pole coils with
residual current (usually obtained from the line cur-
rent transformer) and the lower pole with residual
voltage.
3.1 TYPE CWC RELAY
The type CWC relay has two taps on the upper pole
and four on the lower pole. They are marked in prod-
uct which is the minimum pickup product of two equal
or unequal currents.
Type CWC Relay Ranges and taps are:
.25 to 4 Product Range
Product .25 .36 .64 1.0 1.44 2.56 4.0
2.25 to 36 Product Range
Product 2.25 4.0 6.25 9.0 16.0 25.0 36.0
The first four values are marked on the lower pole tap