5
Auto-reclose relay
module SPCT 5D54
The auto-reclose relay module SPCT 5D54 is
capable of performing from one to five auto-
reclose shots and tripping the circuit breaker
finally. The auto-reclose shots are freely pro-
grammable to be initiated by short circuit, over-
current, earth fault or via an external control
input. When required, the initiation of an auto-
reclose sequence can be blocked by a short
circuit.
An auto-reclose shot can be initiated by start or
trip of the protection. When started by a start
signal of one of the protection modules, the
auto-reclose module opens the circuit breaker,
and when the dead time set for the concerned
AR shot elapses, it closes the circuit breaker.
Should the fault still persist when the auto-
reclosure has been carried out, the protection
relay module operates again initiating the next
shot until the whole AR sequence has been
completed. Then, if the fault proves permanent,
definite tripping will follow. Definite trip can be
carried out either by a protection relay module
or by the auto-reclose module (final trip func-
tion). At definite tripping the red DEF TRIP
indicator on the auto-reclose module is lit and
information about which of the protection func-
tions that initiated the unsuccessful AR se-
quence is available via the output signals.
The auto-reclose module is provided with a
maintenance monitor that records the opera-
tions of the circuit breaker. Each CB opening
decrements the value of the monitor according
to the stress factors. The alarm signal of the
maintenance monitor can be used to block auto-
reclose operations. The maintenance monitor
also allows a pre-alarm level to be set.
Different types of information, e.g., informa-
tion about auto-reclosure in progress, alarm on
definite tripping, and circuit breaker failure
alarm, can also be received as contact informa-
tion from the auto-reclose module.
The external control inputs of the auto-reclose
module can be used to initiate an auto-reclose
sequence, to prevent or interrupt an auto-reclos-
ure and to prevent CB closing.
Circuit-breaker
failure protection
The circuit-breaker failure protection integrated
into the relay modules SPCJ 4D28 and SPCJ
4D28/E351 enables a secured circuit breaker
trip system. The breaker fail function is linked
to the output relay TS1 so that in the event of the
local circuit breaker failing to trip, the trip signal
can be rerouted directly to the upstream circuit
breaker.
Summary of Contents for SPAA 341 C /E351
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