IP^2 Breaker Replacement Program

Challenge: Older infrastructure had a history of poor reliability and the potential to cause issues in the near future
Solution: Replace the oil circuit breakers with more reliable vacuum and gas circuit breakers
Result: New, more reliable breakers reduce the amount of maintenance needed and the power load at each substation

The IP^2 breaker replacement program includes the replacement of 12kV and 34kV breakers based on
existing conditions and operational performance.

Milhouse has been essential, providing engineering design services for some of the breakers in the program.

The initial steps include:
» Upgrading the 12kV breakers with new vacuum circuit breakers (VCBs) and SF6 gas circuit breakers (GCBs)
» Upgrading the transformer relaying to a dual SEL-387 package and an SEL-311C for a transformer differential and breaker protection scheme
» Replace disconnect switches with new hook stick disconnect switches
» As needed, installed new cable trays and cable troughs at substations
» Remove hard-wired legacy SCADA points from the substation
» Install new adapter plates with new VCBs and replace the foundations for new GCBs