Intelligent μC programme for hybrid contactor

Hybrid contactor is a switching device, which while making & breaking an electrical circuit do not draw any arc between its cathode & anode electrode. This is achieved since the making & breaking of the load is done by the solid state device and rated current is carried by the electromechanical contactor. The starting current & its duration being very high for any load, it needs special functionalities for healthy operation of the device. The paper reveals about an intelligent μC programme, which provide a delay between the operation of the solid state device & contactor so as to inhibit high starting current to flow through the contactor & avoid arcing. Also it senses the magnetic field and ambient temperature to overcome the magnetostriction effect upon electromagnet and heating of the SCR. The functionality of the programme is evaluated by means of testing a 32 A hybrid contactor. The test result reveals that during making & breaking operation, there is no arc produced and successfully operated the intended sequence & logic, as per the instruction fed to the programme.