74Cc Close-Circuit Supervision; Overview Of Functions; Structure Of The Function - Siemens 7SR51 Device Manual

6.4

74CC Close-Circuit Supervision

Overview of Functions

6.4.1
The Close‑Circuit Supervision function monitors the integrity of the wiring connections between the
protection device and the circuit‑breaker close coil.
An alarm is issued if the circuit is not complete i.e. an open circuit is detected.
6.4.2

Structure of the Function

The device provides 3 close‑circuit supervision function elements. All elements are identical in operation and
independent from each other allowing 3 close‑circuits to be monitored. This allows close‑circuit monitoring of
both circuit‑breakers with phase segregated close coils or circuit‑breakers with a single common close coil.
1 or more binary inputs can be mapped to 74CCS-n. The inputs are connected into the close‑circuit such that
at least 1 input is energized when the close‑circuit wiring is intact. If all mapped inputs become de-energized
due to a break in the close‑circuit wiring or loss of CB close supply an output is given after a time delay.
The use of 1 or 2 binary inputs mapped to the same close‑circuit supervision element (e.g. 74CCS-n) allows
the user to realize several alternative monitoring schemes.
Reyrolle 7SR5, Overcurrent Protection Device, Device Manual
C53000-G7040-C014-1, Edition 11.2019
Supervision Functions
6.4 74CC Close-Circuit Supervision
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