The APSX4048SW 4000W APS X Series 48V DC 220/230/240V AC Inverter/Charger is a reliable power source for a wide variety of tools and sensitive electronics at mobile, emergency and remote sites. With no fumes, fuel or excess noise, it's an excellent alternative to generator power. It's operable in single-phase mode or three-phase mode for high-capacity industrial and commercial installations. The DC-to-AC pure sine-wave inverter delivers network-grade power. Its automatic line-to-battery transfer switch and integrated charging system allow the unit to work as an extended-run UPS, standalone AC power source or vehicle inverter. It delivers 4000W of continuous power, 6000W up to one minute or 8000W of peak power up to 10 seconds during equipment startup or cycling. An automatic overload detector, cooling fan and resettable AC circuit breakers protect the unit from damage. Designed for easy installation in RVs, commercial and fleet vehicles and emergency vehicles, the APSX4048SW converts stored power from any 48V battery or automotive DC source to safe, stable, computer-grade AC power for unlimited runtime. When hardwired to an external AC source, the unit keeps the user-supplied batteries charged via a three-stage 1~70A selectable charging system while simultaneously delivering AC power to connected equipment. When used as a UPS, the APSX4048SW responds to blackouts and brownouts with an automatic, instantaneous transfer to battery-derived AC output.