Uninterruptible power supplies (UPS), prevents the risk of electric shock from any electric current feeding back from the UPS output in the event of a mains supply failure. When mains fails and connected loads are protected by uninterruptible power supplies, a back-feed protection device prevents current from being passed back to the input terminals of the UPS from the inverter output. For more information visit at  eolapower.com/services/ups-all-in-one.