... useful life of electrical appliancesEliminates the need to switch off appliances every time the electricity failsSafeguards valuable ... cutsSags (under-voltage dip or brownout)Surges (swell or over-voltage)Power-back surges impulses (spike, surge) Automatic ... Low -voltage, Surges/ Spikes, Power back surge, Lightning, Over Current Max.30AWait time30 seconds or 3 minutesApplicationAir-conditioner, large ...