GE Multilin
750/760 Feeder Management Relay
5-27
5 SETPOINTS
5.5 S4 OUTPUT RELAYS
5
5.5S4 OUTPUT RELAYS
5.5.1 RELAY OPERATION
a) DESCRIPTION
The 750/760 relay is equipped with eight electromechanical output relays: three special purpose (Trip Relay 1, Close Relay
2, and Self-test Warning Relay 8) and five general purpose (Auxiliary Relays 3 to 7). The special purpose relays have fixed
operating characteristics and the general purpose relays can be configured by the user. Logic diagrams for each output
relay are provided for detailed explanation of their operation.
b) TRIP AND CLOSE RELAYS
Operation of these breaker-control relays is designed to be controlled by the state of the circuit breaker as monitored by a
52a or 52b contact. Once a feature has energized one of these relays it will remain operated until the requested change of
breaker state is confirmed by a breaker auxiliary contact and the initiating condition has reset. If the initiating feature resets
but the breaker does not change state, the output relay will be reset after either the delay programmed in the Breaker Oper-
ation feature or a default interval of 2 seconds expires. If neither of the breaker auxiliary contacts 52a nor 52b is pro-
grammed to a logic input, the Trip Relay is de-energized after either the delay programmed in the Breaker Failure feature or
a default interval of 100 ms after the initiating input resets and the Close Relay is de-energized after 200 ms. If a delay is
programmed for the Trip or Close contact seal in time, then this delay is added to the reset time. Note that the default set-
ting for the seal in time is 40 ms.
c) AUXILIARY RELAYS 3 TO 7
Operation of these relays is programmed by the user. Each relay can be selected to become either energized or de-ener-
gized when operated, and to operate as latched, self-resetting or pulsed.
Table 5–2: BREAKER AUXILIARY CONTACTS AND RELAY OPERATION
52A CONTACT
INSTALLED?
52B CONTACT
INSTALLED?
RELAY OPERATION
Yes
Yes
Trip Relay remains operating until 52b indicates an open breaker.
Close Relay remains operating until 52a indicates a closed breaker.
Yes
No
Trip Relay remains operating until 52a indicates an open breaker.
Close Relay remains operating until 52a indicates a closed breaker.
No
Yes
Trip Relay remains operating until 52b indicates an open breaker.
Close Relay remains operating until 52b indicates a closed breaker.
No
No
Trip Relay operates until either the Breaker Failure delay expires (if the
Breaker Failure element is enabled) or 100 ms after the feature causing
the trip resets.
Close Relay operates for 200 ms.
Table 5–3: AUXILIARY RELAY OPERATION
OUTPUT TYPE
DESCRIPTION
Latched
Upon being operated by any programmed feature, the relay output contacts change state and remain in the new
state. The relay can be returned to the non-operated state only by the RESET key, the reset logic input, or a
computer reset command. This mode is used for alarms which must be acknowledged, or to provide a lockout
function.
Self-resetting
Upon being operated by any programmed feature, the relay output contacts change state and remain in the new
state until all features which operate the relay are no longer signaling it to operate. For a relay operated by a
single feature, the output contacts follow the state of the feature.
Pulsed
Upon being operated by any programmed feature, the relay output contacts change state and remain in the new
state for a programmed time interval called the
PULSED OUTPUT DWELL TIME
. The dwell timer is started when
the first feature causes operation of the output relay.
