Method, system and apparatus for employing neutral poles in multipole circuit breakers

A neutral pole for a multipole circuit breaker, the circuit breaker having a housing, a plurality of contact arms for opening and closing an electrical circuit and an operating mechanism for driving the contact arms, the neutral pole comprising:

• a neutral housing;
• a conduction path within said neutral housing leaving a neutral arm arranged to open and close said conduction path;
• a bias spring configured to exert a first bias moment on said neutral arm when said conduction path is closed;
• a spring support configured to support said bias spring, said spring support being fixedly arranged at said neutral housing;
• a rotor pivotally arranged within said neutral housing and configured to displace said neutral arm and open said conduction path;
• and
• a drive pin configured to couple said rotor to the multipole circuit breaker, said rotor being responsive to the opening and closing action of the opening mechanism of the multipole circuit breaker;
• wherein said rotor is in a first orientation when said conduction path is closed, a second orientation when said rotor makes contact with said neutral arm when opening, said conduction path, and a third orientation when said conduction path is open, said bias spring exerting a bias force on said neutral arm that is not transmitted to said rotor when said rotor is between said first and second orientations, and said bias spring exerting a bias force on said neutral arm that is transmitted to said rotor when said rotor is between said second and third orientations.

A multipole circuit breaker, comprising:

• a main housing;
• a main conduction path having a plurality of contact arms configured to open and close an electrical circuit;
• an operating mechanism configured to drive said contact arms;
• and
• a neutral pole, comprising:
• a neutral housing in fixed arrangement with said main housing;
• a neutral conduction path within said neutral housing having a neutral arm arranged to open and close said neutral conduction path;
• a bias spring configured to exert a first bias force on said neutral arm when said neutral conduction path is closed;
• a spring support configured to support said bias spring, said spring support being fixedly coupled to said neutral housing;
• a rotor pivotally arranged within said neutral housing and arranged to displace said neutral arm and to open said neutral conduction path;
• and
• a drive pin configured to couple said rotor to said operating mechanism, said rotor being responsive to the opening and closing action of said operating mechanism;
• wherein said neutral arm opens subsequent to the opening of said plurality of contact arms and closes prior to the closing of said plurality of contact arms during an opening and closing action, respectively.