摘要 |
A circuit for detecting whether, or not, a three-phase load is correctly connected to a three-phase supply employs an inductance, capacitor and resistor connected in the three branches of the load circuit so as to generate a single phase output signal when connected to the supply, to voltage of the signal depending upon the connection to the supply. The circuit requires only three wires and not connected to a ground, or neutral. The output signal controls a reversing switch to ensure that the load is always automatically connected correctly; in a preferred form only one of the voltages is sufficient to light a source of radiant energy to activate a sensor to energize the reversing switch.
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