Electrical Installation469Motor Management RelayInstallationhttp://www.GEindustrial.com/multilin3–22 GE MultilinFIGURE 3–27: RS485 Communications WiringDielectric Strength It may be required to test a complete motor starter for dielectric strength (“flash” or“hipot”) with the 469 installed. The 469 is rated for 2000 V DC isolation betweenrelay contacts, CT inputs, VT inputs, trip coil supervision, and the safety groundterminal G12. Some precautions are required to prevent damage to the 469 duringthese tests.Filter networks and transient protection clamps are used between control power, tripcoil supervision, and the filter ground terminal G11. This is intended to filter outhigh voltage transients, radio frequency interference (RFI), and electromagneticinterference (EMI). The filter capacitors and transient suppressors may be damagedby continuous high voltage. Disconnect the filter ground terminal G11 during testingof control power and trip coil supervision. The CT inputs, VT inputs, and outputrelays do not require any special precautions. Low voltage inputs (less than 30 V),RTDs, analog inputs, analog outputs, digital inputs, and RS485 communication portsare not to be tested for dielectric strength under any circumstance (see below).
