Maintenance Following Tripping Of A Molded Case Circuit Breaker - Siemens 3VA1 100 A Manual

5.3

Maintenance following tripping of a molded case circuit breaker

If a 3VA molded case circuit breaker trips on overcurrent (overload, short circuit) or residual
current (ground fault or via residual current device), the cause of the trip must be identified
and rectified before the molded case circuit breaker is switched on again.
In the case of 3VA1 molded case circuit breakers with thermal-magnetic trip units, the cause
of tripping can be determined, for example, with the assistance of the short circuit alarm
switches SAS. With 3VA2 molded case circuit breakers, the cause of tripping can be output
via the EFB300 external function box. With electronic trip units ETU 5-series and 8-series,
the cause of tripping can be indicated on the LCD display and optionally transferred via
communication modules.
An inspection as described in chapter Regular maintenance (Page 419) should be carried
out every time the molded case circuit breaker is tripped by the trip unit. In addition, all black
residues on the molded case circuit breaker must be removed as they might contain
conductive particles. The molded case circuit breaker should then be switched on and off
without load at least five times.
3VA molded case circuit breakers
Manual, 04/2015, A5E03603177010-02
5.3 Maintenance following tripping of a molded case circuit breaker
Service and maintenance
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