Bank-in-Service caps are __________ devices that are applied to the control handles of closed bank CBs.

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

Answer: (A)

Bank-in-Service caps are blocking devices that physically obstruct the control handles of closed bank circuit breakers. When a bank is in service, these caps are placed on the handles to prevent any movement into other positions, so no closing (or opening) actions can be made accidentally. They act as a simple, tangible safeguard—until authorized personnel remove the cap as part of a lockout or maintenance procedure, the bank remains effectively protected from unintended operation. The other ideas don’t fit because shunting would bypass circuits, grounding would create a fault path, and interlocking involves more complex gating than a simple physical cap on a handle.