Modified magne-blast circuit breaker and method of modification

A modified magne-blast vertical racking circuit breaker comprising:

• a main frame including a wheeled chassis adapted to be received in a power switchgear assembly, and having a pair of vertically-extending brackets on a forward end thereof;
• a vacuum breaker operating mechanism having a housing attached to said brackets;
• a plurality of breaker pole units actuated by said operating mechanism and mounted within said main frame, each of said breaker pole units including
• a vertically-oriented vacuum interrupter having an actuating rod extending downwardly therefrom, said actuating rod being operatively connected to said operating mechanism,
• a line stab extending upwardly from said frame and positioned adjacent to said vacuum interrupter, said line stab having a boss extending downwardly therefrom adjacent to a top surface of said vacuum interrupter,
• a top bus bar connected at a midportion thereof to said top surface, at a forward end to said housing by an insulated connection and at a rearward end to said line stab boss, and
• a load stab extending upwardly from said frame and positioned rearward of said line stab, said load stab having a boss extending downwardly therefrom at an elevation below said vacuum envelope,
• a bottom bus bar connected at a midportion thereof to said rod, at a forward end to said housing by an insulated connection, and at a rearward end to said load stab boss;
• mechanism operated cell means, mounted on said main frame above said operating mechanism, for engaging switchgear such that said switchgear activates said operating mechanism;
• and
• interlock operator means, operatively connected to said operating mechanism and including a cam pivotably journaled in said operating mechanism and extending sidewardly therefrom, for engaging a cam slot on said switchgear assembly to prevent said circuit breaker from being in a closed condition during vertical racking thereof.