These specifications are intended as a reference for purchasers and users of circuit breakers in the preparation of requests for quotations and as a reference for manufacturers and vendors in submitting bids. These specifications apply to all types of alternating-current power circuit breakers (indoor and outdoor) having an interrupting rating of 50 mva or higher and a voltage rating above 1500 volts. Individual clauses apply to all types except where otherwise indicated. These requirements of necessity include some elements of construction and materials, but are not intended to preclude ingenuity of design or improvement.

These specifications are intended as a reference for purchasers and users of circuit breakers in the preparation of requests for quotations and as a reference for manufacturers and vendors in submitting bids. 12-1.2 These specifications apply to all types of alternating- current power circuit breakers (indoor and outdoor) having an interrupting rating of 50 mva or higher and a voltage rating above 1500 volts. Individual clauses apply to all types except where otherwise indicated. 12-1.3 These requirements of necessity include some elements of construction and materials, but are not intended to preclude ingenuity of design or improvement.