ABB CWC Instruction Leaflet page 5

Type CWC and CWP Directional Ground Relay
plate. The upper pole tap plate is marked x 1 and x 4
Product. The last four values are obtained by using
the x 4 tap with the four lower pole taps.
*
Typical 60 Hertz time-product curves for the type
CWC relay are shown in Fig. 9. These curves are
taken at maximum torque which occurs with the cur-
rents in phase. For residual and Ground currents out
of phase the relay operating time may be obtained
by determining the operating time corresponding to
the product P' - P Cos Ø, where P is the actual relay
product in amperes squared, and Ø is the angle
between the residual and polarizing currents.
The limits for which these curves are accurate within
± 7% are shown in Fig. 10.
3.2 TYPE CWP RELAY
The type CWP relay taps are on the upper pole cur-
rent coil. They represent the minimum pickup prod-
uct of current times voltage at maximum torque
when the current lags the voltage by 60 °. The range
and taps are:
Product
Range
20 - 150 20 30
75 - 600 75 100 150 200 300 400 600
Typical 60 Hertz time product curves for the type
*
CWP relay are shown in Fig. 11. These curves are
Tap Markings
40 50 75 100 150
taken at maximum torque which occurs with the cur-
rent lagging the voltage 60 °. For currents not lag-
ging by this angle, the relay tripping time may be
obtained by determining the operating time corre-
sponding to the product p' = P Cos (60 ° - 6), where
P is the actual relay V.A. product and a is the angle
the current lags the voltage. The curves are accurate
within ± 7% if the multiple of tap product does not
exceed the voltage on the relay coil.
3.3 TRIP CIRCUIT
The main contacts will safely close 30 amperes at
250 volts d-c and the seal-in contacts of the indicat-
ing contactor 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 d-c, and will carry this
current long enough to trip a breaker.
The indicating contactor switch has two taps that
provide a 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.
3.4 TRIP CIRCUIT CONSTANT
Indicating Contactor Switch (ICS)
0.2 ampere tap 6.5 ohms d-c resistance
2.0 ampere tap 0.15 ohms d-c resistance
41-242.2F
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