I have several definite-purpose circuit breakers type SPS2-145-50-1 associated with a 115 kV bus system. There are also three 50 MVA capacitor banks connected to the same bus as these breakers. The breakers in question do not switch in the cap banks but hang off of the same bus. My concern is...
I have several vacuum switches used for cap banks that have recently been found to be over-dutied. The momentary for the switches is 15kA, and currently there is roughly 25kA of fault duty available.
The switches are protected by SMU-20 fuses, which initally was thought to protect the...