Molded case circuit breaker having instantaneous trip mechanism

A molded case circuit breaker comprising:

• a plurality of main circuit units located in a lower compartment of the molded case circuit breaker, wherein each of the plurality of main circuit units is configured to open or close a circuit via a stationary contactor and a movable contactor, wherein the movable contactor is rotatable to make contact with or separate from the stationary contactor;
• a switching mechanism located in an upper compartment of the molded case circuit breaker, the switching mechanism connected to each of the plurality of main circuit units and having:
• an open position in which the switching mechanism drives open a circuit, and
• a closed position in which the switching mechanism drives each of the plurality of main circuit units to close the circuit;
• an instantaneous trip mechanism located in the upper compartment and operated via electromagnetic attraction in response to generation of a fault current in the circuit, wherein the instantaneous trip mechanism causes the switching mechanism to be in the open position;
• and
• an intermediate insulation barrier installed commonly for the plurality of main circuit units between the upper compartment and the lower compartment and configured to provide electrical insulation between the switching mechanism and instantaneous trip mechanism located in the upper compartment and the plurality of main circuit units located in the lower compartment by partitioning the lower compartment and the upper compartment, wherein the intermediate insulation barrier is a portion of and forms a single body with an upper outer casing of the molded case circuit breaker, and
• wherein the intermediate insulation barrier is configured to substantially cover the entire area of the lower compartment.