The device is designed to detect and prevent the refrigerator, freezer and other electrical equipment. Appliances to prevent damage from a power failure (The power up or The power surges), helping to extend the useful life of the appliance when the power pressure out of range +15% of the nominal. The relay will automatically break the circuit to prevent device damage when the pressure returned to normal, The delay circuit will start counting time until as set relay to work automatic (Energize) which purpose of the delay circuit to prevent air compressor damage)