MSV/FSV medium-voltage replacement circuit breaker safety advisory

The FSV and MSV breakers are roll-in replacement circuit breakers designed to replace original Siemens/Allis-Chalmers F and D gear. While the circuit breakers have a reliable track record in service, those manufactured prior to May 2002 have interlock system linkages which may be damaged from application of excessive forces to the trip free linkage or from use of excessive force while moving the circuit breaker between the DISCONNECT and TEST or CONNECT positions.

Does your circuit breaker require an update?

For Siemens type MSV circuit breaker:

 

Review the images below to determine if your circuit breaker needs to be updated.

External inspection: MSV circuit breaker - racking release handle

Internal inspection: MSV circuit breaker - behind operator mechanism upper cover

For Siemens type FSV circuit breaker:

 

Review the images below to determine if your circuit breaker needs to be updated.

 

External inspection: if the tilt-panel tabs are installed as shown in the photographs below, you have th latest interlock system and no further action is required. If possible, you should also confirm the construction by internal inspection as described below. If the tilt-panel tabs are not present, the interlock system must be updated. There may or may not be hardware associated with the installation of the tilt panel tabs.

External inspection: rebuilt FSV Circuit Breaker, tilt-panel tabs

Internal inspection: FSV circuit breaker - behind operator mechanism upper cover

How to identify a 3AH or 3AF operator:

If your circuit breakers require updating, please contact Siemens immediately.