Ge 489 User Manual download pdf (Page 70)

4-20 489 Generator Management Relay GE Multilin

4.5 S4 OUTPUT RELAYS 4 SETPOINTS

4.5S4 OUTPUT RELAYS 4.5.1 DESCRIPTION

Five of the six output relays are always non-failsafe, R6 Service is always failsafe. As failsafe, R6 relay will be energized

normally and de-energize when called upon to operate. It will also de-energize when control power to the 489 is lost and

therefore, be in its operated state. All other relays, being non-failsafe, will be de-energized normally and energize when

called upon to operate. Obviously, when control power is lost to the 489, the output relays must be de-energized and there-

fore, they will be in their non-operated state. Shorting bars in the drawout case ensure that when the 489 is drawn out, no

trip or alarm occurs. The R6 Service output will however indicate that the 489 has been drawn out.

4.5.2 RELAY RESET MODE

PATH: SETPOINTS ÖØ S4 OUTPUT RELAYS Ö RELAY RESET MODE

Unlatched trips and alarms will reset automatically once the condition is no longer present. Latched trip and alarm features

may be reset at any time, providing that the condition that caused the trip or alarm is no longer present and any lockout time

has expired. If any condition may be reset, the Reset Possible LED will be lit. The relays may be programmed to All Resets

which allows reset from the front keypad or the remote reset digital input or the communications port. Optionally, they may

be programmed to reset by the Remote Reset Only (by the remote reset digital input or the communications port).

For example, selected trips such as Instantaneous Overcurrent and Ground Fault may be assigned to R2 so that they may

only be reset via. the Remote Reset digital input or the Communication Port. The Remote Reset terminals would be con-

nected to a keyswitch so that only authorized personnel could reset such a critical trip.

• Assign only Short Circuit and Ground Fault to R2

• Program R2 to Remote Reset Only

 RELAY RESET MODE

 [ENTER] for more

R1 TRIP:

All Resets