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10.3 Warning Concerning Hi-Pot and Dielectric Testing of the System
As the Sigma monitor relay, NGRS-XX sensing resistor and ZSCS have undergone and passed high-pot testing at
the factory, field testing of the relay is unnecessary and may damage these components. For any high-pot tests or
dielectric withstand tests on the system conducted in the field, the Sigma monitor relay, NGRS-XX sensing resistor
and ZSCS must be prepared as described below to avoid damaging this equipment.
1)
Ensure all control circuits are disconnected and insulated.
2)
Disconnect the conductor on terminal R of the NGRS-XX sensing resistor from the Sigma monitor relay
and ensure the conductor is insulated.
3)
Disconnect the conductor on terminal G of the NGRS-XX sensing resistor from ground and ensure the con-
ductor is insulated.
4)
Disconnect the conductors between the X1 and X2 terminals of the ZSCS and the Sigma monitor relay and
ensure these conductors are insulated.
5)
Disconnect the control power leads from the Sigma monitor relay and ensure these conductors are insulated
6)
Connect short conductors between the L, N and G terminals of the Sigma monitor relay ensuring that the G
terminal remains connected to ground.
7)
Perform the high-pot or dielectric withstand tests required.
8)
Reconnect the conductors between the X1 and X2 terminals of the CT and the Sigma monitor relay.
9)
Reconnect the conductor between terminal G of the NGRS-XX sensing resistor and the appropriate
terminal on the Sigma monitor relay. Refer to Figure 3.1.
10)
Reconnect the conductor from the G terminal on the NGRS-XX sensing resistor to ground.
11)
Remove the conductors added between the L, N and G terminals of the Sigma monitor relay ensuring that
the G terminal remains connected to ground.
12)
Reconnect the conductor from the R terminal of the NGRS-XX sensing resistor to the appropriate terminal of
the Sigma monitor relay. Refer to Figure 3.1.
13)
Reconnect all control circuits which were disconnected in step 1.
14)
Reconnect the control power to the L and N terminals of the Sigma monitor relay.