The Compressor Defender™ is the only all-in-one under voltage and surge power protection device on the HVAC Market, providing protection for central A/C and heat pump condensing units and their associated motors, controls and components-both electronic and mechanical. It can be installed inside the condensing unit or externally on the outdoor A/C disconnect. Autosense voltage technology protects at any voltage from 120-240 VAC, making it an Ideal solution for residential or light commercial installations. Trusted, state-of-the-art TPMOV® (Thermally Protected Metal Oxide Varistor) surge protection technology eliminates the potentially hazardous failure modes that are associated with standard MOV technology. The device is also designed with integrated, 3-minute short cycle time delay protection.