Bank-in-Service caps are applied to closed bank CBs as blocking devices; what term describes this function?

• A. Blocking caps
• B. Shunting caps
• C. Grounding caps
• D. Interlocking caps

Answer: (A)

Blocking caps are used to enforce safe switching sequences in a bank of circuit breakers. When a bank is in service and one or more breakers are closed, these capacitors are placed on the closed bank CBs to block the operation of other breakers in the same bank from closing. They essentially block the closing path in the control circuit, preventing accidental or unwanted re-closure into a live bus and helping to maintain proper isolation and sequence. This is why the term blocking caps fits: their job is to block certain closing actions to keep the system safe and correctly staged. The other options describe different functions (shunting, grounding, or interlock-related terms) that do not perform the explicit blocking role described here.