Add-on trip module for multi-pole circuit breaker

A multiple-pole circuit breaker comprising

• a basic mechanical structure that includes, for each pole,
• a power input terminal and a power output terminal,
• a pair of contacts each of which is connected to a different one of said terminals and at least one of which is movable,
• a trip mechanism coupled to said movable contact for opening said contacts by disengaging said movable contact from the other contact in said pair, and
• a manually operable actuator coupled to said movable contact for operating and resetting said trip mechanism, and
• an add-on module adapted to be attached to said basic mechanical structure and including
• multiple extended terminal plates each of which is adapted to replace one of said terminal plates for one of said phase lines,
• multiple electromechanical transducers each of which is coupled to one of said extended terminal plates for producing a mechanical movement in response to a predetermined magnitude of electrical current in the extended terminal plate to which that transducer is coupled,
• a mechanical actuator coupled to said electromechanical transducers and to said movable contacts for operating said trip mechanism in response to a predetermined movement of any of said transducers, and
• a calibration element for adjusting mechanical movement of at least one of said multiple electromechanical transducers so as to control an aspect of trip actuation.