Functions
148
7SS52 V4 Manual
C53000-G1176-C182-1
5.5.1.10 Supervisory of Circuit Breaker
Interrogation of the feeder circuit breaker is required for the end fault protection func-
tion (Chapter 5.4, page 132) and for low-current circuit breaker failure protection mode
(Chapter 5.3.5.2, page 118).
Three circuit breaker signals can be recognized:
• CB in CLOSED position (CB CLOSED)
• CB in OPEN position (CB OPEN)
• Circuit breaker CLOSE control command (CB CLOSE command)
The circuit breaker status is recognized by marshalling it to binary inputs of the bay
unit. For safety reasons, we recommend an external logic link for phase-selective cir-
cuit breaker auxiliary contacts. The final position of the circuit breaker is only recog-
nized (Bild 5-38, page 148) if all three auxiliary contacts are closed.
If the CLOSED and OPEN position is continuously implausible for a longer period than
set in the parameter CB SUP TIME (6315/CU), this leads to a fault annunciation
(Tabelle 5-3, page 149).
The setting of the runtime monitoring of the circuit breaker with the parameter
CB SUP TIME (6315/CU) serves for a better adaptation of the sequences to the
switching operations (e.g. single-pole AR).
The duration of the CLOSE command is separately monitored because false informa-
tion at the binary input would cause a deterioration of the end fault protection (Chapter
5.4.1, page 132) and/or of the function ”Protection in the dead zone of the bus coupler”
(Chapter 5.4.2, page 134).
Bild 5-38 Interrogation of circuit breaker