Abstract: Disclosed is a magnetic circuit breaker having improved delay characteristics and particularly improved pulse tolerance. The trip coil of the breaker is spaced from the magnetic pole piece of a delay tube by a non-conductive, non-magnetic gap and the delay core is elongated. An inertia wheel is mechanically coupled to the trip armature to further increase pulse tolerance so as to reduce nuisance tripping in the presence of high but very short term overcurrents. The circuit breaker provides a significantly improved motor protection characteristic.

Abstract: Disclosed is a molded case type magnetic circuit breaker having improved performance and an increased current rating. A corrosion and temperature resistant stainless steel wire screen having specific wire and mesh opening sizes overlies a novel exhaust gas baffle arrangement to cool and disperse arc chamber gases venting from the breaker. Flashover during high current switching, due to conduction through the exhaust gas plasma, is eliminated. Also disclosed is a novel arc chamber construction for the circuit breaker and a marine baffle for adapting the breaker to use in potentially explosive atmospheres.

Abstract: Disclosed is a magnetic circuit breaker having improved delay characteristics and particularly improved pulse tolerance. The trip coil of the breaker is spaced from the magnetic pole piece of a delay tube by a non-conductive, non-magnetic gap and the delay core is elongated to extend in its normal biased position through the electrical center of the coil. An inertia wheel is mechanically coupled to the trip armature to further increase pulse tolerance so as to reduce nuisance tripping in the presence of high but very short term overcurrents.