A motor is located 100 feet from the motor control center that houses the motor branch-circuit disconnect. An instantaneous-trip circuit breaker can be used for the 'within-sight' motor disconnect. This would entail the instantaneous-trip circuit breaker being installed alone in a separate enclosure.

A motor is located 100 feet from the motor control center that houses the motor branch-circuit disconnect. An instantaneous-trip circuit breaker can be used for the 'within-sight' motor disconnect. This would entail the instantaneous-trip circuit breaker being installed alone in a separate enclosure.

• A. True
• B. False
• C. Only if inside a listed enclosure
• D. It must be a fused disconnect

Answer: (B)

Motor disconnects that must be within sight of the motor need to be a listed disconnecting means, and when you choose a circuit breaker as that disconnect, it has to be part of a listed motor controller arrangement. Using an instantaneous-trip circuit breaker installed alone in a separate enclosure does not meet that requirement because it isn’t provided as a listed, integrated motor protection/disconnect assembly. In practice, the disconnect and the protective coordination must come from a listed device or a listed combination starter that includes both the disconnecting means and the overload protection. So, placing a standalone instantaneous-trip breaker in its own enclosure as the within-sight disconnect isn’t compliant.

Motor disconnects that must be within sight of the motor need to be a listed disconnecting means, and when you choose a circuit breaker as that disconnect, it has to be part of a listed motor controller arrangement. Using an instantaneous-trip circuit breaker installed alone in a separate enclosure does not meet that requirement because it isn’t provided as a listed, integrated motor protection/disconnect assembly. In practice, the disconnect and the protective coordination must come from a listed device or a listed combination starter that includes both the disconnecting means and the overload protection. So, placing a standalone instantaneous-trip breaker in its own enclosure as the within-sight disconnect isn’t compliant.