What is the difference between a molded case and an insulated case breaker?

FA109848

28 September 2021

Product Line:
Circuit Breakers

Environment:
Electrical Distribution Equipment

Resolution:
An insulated case circuit breaker is a molded case circuit breaker with an integral 2 step stored-energy mechanism. They have the functionality of an iron frame breaker, or a low voltage power breaker with a molded plastic instead of an iron frame.

Examples:
Masterpact MTZ, NW, NT breakers are molded case breakers, but are considered to be insulated case breakers due to the inclusion of the 2 step stored energy mechanism (charging handle).
Powerpact B, H, J, L, M, P, and R breakers are molded case breakers.