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1MRS 755310
Feeder Protection Relay
Technical Reference Manual
for the operation of the circuit breakers of the incoming and outgoing feeders.
Consequently, the REF 610 relays in the station can, for instance, be set to trip the
circuit breaker of either the incoming or the outgoing feeder depending on the fault
location in the switchgear. For maximum safety, the REF 610 relays can be set to
always trip both the circuit breaker of the incoming feeder and that of the outgoing
feeder.
The arc protection consists of:
• optional arc light detection hardware with automatic backlight compensation for
two lens sensors
• a light signal output for routing the locally detected light signal to another relay
• the protection stage ARC with phase- and earth-fault current measurement.
The light from an arc is detected either locally or via a remote light signal. Locally,
the light is detected by lens sensors connected to inputs Light sensor 1 and Light
sensor 2 on the serial communication module of the relay. The lens sensors can be
placed, for instance, in the busbar compartment and the cable compartment of the
metal-clad cubicle.
The light detected by the lens sensors is compared to an automatically adjusted
reference level. Inputs Light sensor 1 and Light sensor 2 have their own reference
levels. When the reference level of either or both inputs is exceeded, an arc has been
detected locally.
When light has been detected locally or remotely and one or several phase currents
exceed the set current limit ArcI>, or the earth-fault current the set current limit
ArcI
>, the arc protection stage (ARC) will generate a trip signal in less than 15 ms.
0
The stage will be reset in 30 ms after all three phase currents and the earth-fault
current have fallen below the set current limits.
The light signal output, L>, can be configured to be activated either immediately
upon detection of light in all situations, or only when the arc has not been
extinguished by the time the trip signal is generated. The selection is made in SGF4.
By routing the light signal output to an output contact connected to a digital input of
another REF 610 relay, a station-wide arc protection is realized.
Stage ARC and the light signal output can be set out of operation in SGF3.
Note!
Inputs not in use should be covered with dust caps.
Note!
The warning signal generated in case of continuous light on the light sensor inputs
can be routed to SO2 by setting switch SGF1/8 to 1.
REF 610
27
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