Abstract: A circuit breaker having an external trip indicator, having a circuit breaker housing, a trip mechanism within the housing, sensing a trip condition and being responsive thereto to mechanically break an electrical circuit, an indicator, having a selectively operable retaining mechanism and being biased outward from the circuit breaker housing, and a linkage, sensing a trip condition of the trip mechanism and selectively releasing the selectively operable retaining mechanism to allow the indicator to move outwardly from the housing. The external trip indicator is operated by sensing an overcurrent condition with the trip mechanism, breaking the electric circuit in response to the overcurrent, sensing a mechanical movement of the trip mechanism, and thereby releasing a positional restraint on the mechanical indicator; and allowing the mechanical indicator to protrude from the housing.

Abstract: A parallel pole magnetohydraulic circuit breaker, having a single trip element and a pair of trip mechanisms, achieving an increased current carrying capacity with reduced nuisance trips. The trip mechanisms are contained within separate housings, with electrical connections and multipole trip mechanism communicating through apertures in the common wall. Preferably, the armature of the trip element acts on a single trip mechanism, which multiplies the available force to trigger a trip of the other trip mechanism.