Ge 489 User Manual download pdf (Page 31)

GE Multilin 489 Generator Management Relay 2-15

2 INSTALLATION 2.2 ELECTRICAL

2.2.13 DIELECTRIC STRENGTH

It may be required to test a complete motor starter for dielectric strength (“flash” or hi-pot”) with the 489 installed. The 489 is

rated for 1.9 kV AC for 1 second or 1.6 kV AC for 1 minute (per UL 508) isolation between relay contacts, CT inputs, VT

inputs, trip coil supervision, and the safety ground terminal G12. Some precautions are required to prevent damage to the

489 during these tests.

Filter networks and transient protection clamps are used between control power, trip coil supervision, and the filter ground

terminal G11. This filtering is intended to filter out high voltage transients, radio frequency interference (RFI), and electro-

magnetic interference (EMI). The filter capacitors and transient suppressors could be damaged by application continuous

high voltage. Disconnect filter ground terminal G11 during testing of control power and trip coil supervision. CT inputs, VT

inputs, and output relays do not require any special precautions. Low voltage inputs (<30 V), RTDs, analog inputs, analog

outputs, digital inputs, and RS485 communication ports are not to be tested for dielectric strength under any circumstance

(see below).

Figure 2–17: TESTING THE 489 FOR DIELECTRIC STRENGTH

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Ge 489 User Manual Page 31