| 摘要 |
A motor starter includes a contactor and an overload relay. The overload relay includes a power supply having a voltage, a processor powered by the power supply voltage and being structured to control the contactor, and an overvoltage circuit. The overvoltage circuit includes a voltage reference having a voltage, a comparator, a load and a switch. The comparator includes a first input for the power supply voltage, the first input cooperating with the voltage of the voltage reference to determine a threshold voltage, a second input for voltage reference voltage, and an output. The switch is controlled by the comparator output and is structured to electrically connect the power supply voltage to ground through the load whenever the power supply voltage exceeds the threshold voltage.
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