Appliances such as fridges, all IT equipment, emergency lights, etc. which are supplied by the public grid and cannot afford any power cut, are electrically secured. An inverter/charger with fast transfer relay or a combination of an inverter and a charger guarantees that the battery is well maintained and that an uninterrupted power supply to strategic appliances is sustained. CET offers solutions from 200 VA up to 150 kVA with a one of a kind product choice that remains unchallenged on the market.