3-8 L90 Line Differential Relay GE Multilin3.2 WIRING 3 HARDWARE33.2.3 CONTROL POWERCONTROL POWER SUPPLIED TO THE RELAY MUST BE CONNECTED TO THE MATCHING POWER SUPPLYRANGE OF THE RELAY. IF THE VOLTAGE IS APPLIED TO THE WRONG TERMINALS, DAMAGE MAYOCCUR!The L90 relay, like almost all electronic relays, contains electrolytic capacitors. These capacitors are wellknown to be subject to deterioration over time if voltage is not applied periodically. Deterioration can beavoided by powering the relays up once a year.The power supply module can be ordered for two possible voltage ranges. Each range has a dedicated input connection forproper operation. The ranges are as shown below (see the Technical Specifications section for additional details):ï LO range: 24 to 48 V (DC only) nominalï HI range: 125 to 250 V nominalThe power supply module provides power to the relay and supplies power for dry contact input connections.The power supply module provides 48 V DC power for dry contact input connections and a critical failure relay (see theTypical Wiring Diagram earlier). The critical failure relay is a Form-C that will be energized once control power is appliedand the relay has successfully booted up with no critical self-test failures. If on-going self-test diagnostic checks detect acritical failure (see the Self-Test Errors table in Chapter 7) or control power is lost, the relay will de-energize.Figure 3ñ9: CONTROL POWER CONNECTION3.2.4 CT/VT MODULESA CT/VT module may have voltage inputs on Channels 1 through 4 inclusive, or Channels 5 through 8 inclusive. Channels1 and 5 are intended for connection to Phase A, and are labeled as such in the relay. Channels 2 and 6 are intended forconnection to Phase B, and are labeled as such in the relay. Channels 3 and 7 are intended for connection to Phase C andare labeled as such in the relay. Channels 4 and 8 are intended for connection to a single phase source. If voltage, thischannel is labelled the auxiliary voltage (VX). If current, this channel is intended for connection to a CT between a systemneutral and ground, and is labelled the ground current (IG).a) CT INPUTSVERIFY THAT THE CONNECTION MADE TO THE RELAY NOMINAL CURRENT OF 1 A OR 5 A MATCHESTHE SECONDARY RATING OF THE CONNECTED CTs. UNMATCHED CTs MAY RESULT IN EQUIPMENTDAMAGE OR INADEQUATE PROTECTION.CAUTIONNOTECAUTION
