SVP-912M SINOTIMER brand automatic over-voltage and under-voltage protector is suitable for single-phase AC 230V, 50/60Hz, rated working current 40A. It is mainly used for residential household box entry or over-voltage, under-voltage of distribution lines for single-phase electrical equipment. Its main feature is when the circuit has over-voltage or under-voltage problems, the product can cut off the power supply instantaneously to protect the electrical equipment from being damaged, besides,the protector can automatically turn on the power supply when the circuit voltage returns to the normal.