Siemens SENTRON 3VL System Manual page 144

Service and maintenance
11.2 Troubleshooting
Circuit breaker status
Mechanical and
High humidity
electrical functions:
Corrosion
Function of the internal
accessories
144
Causes of faults
The circuit breakers must not be used in environments with high
humidity since this can cause dielectric and insulation problems. In
such environments, appropriate measures need to be taken, such as
placing the circuit breaker in an enclosure.
The circuit breakers are not designed to be used in aggressive
environments.
In such environments, the circuit breaker should be installed in a
housing.
Determine what type of internal accessories are installed. Remove the
circuit breaker cover and determine the type of accessories using the
circuit breaker order number. Then check for correct functioning.
•
Ensure the correct voltage is connected to the undervoltage release
since otherwise, the circuit breaker cannot be tripped.
•
Ensure the voltage is not applied to the shunt release since this can
also prevent the circuit breaker from tripping.
•
The auxiliary and alarm switches do not have any effect on the
functioning of the circuit breaker.
Corrective action
Undervoltage release:
Shunt release:
Auxiliary and alarm switches:
3VL molded-case circuit breakers
System Manual, 03/2009, 110 0110 - 02 DS 01