Pure Sine Wave Online UPS system 1K-20Kva Key features 1: True on-line double conversion technology with advanced microprocessor control 2: Wide input voltage range 3: Zero transfer time 4: Protection against all type of power problems, Like: power sags, high voltage spikes, switching transients, power surges, noise, frequency variation, brownout. Overload, Short Circuit, Overcurrent, Unbalanced Loads, Overvoltage 5: Self test while start of the UPS 6: Site wiring fault warning 7: On-battery power-on function 8: Smart RS232 and USB communication interface 9: Intelligent SNMP Card slot available 10: Built-in Sealed lead acid, maintenance free battery 11: Pure sine wave output 12: Single Phase In/Out for UPS 1-10Kva, Three Phase In and Single Phase out for UPS10-20Kva 13: Large LCD Display Large blue back light LCD for detailed real-time UPS status display 14: Microprocessor control guarantees high reliability 15: Comprehensive self-protection design 16: Audible alarm mute 17: Cold start function 18: Auto self-testing system while turning on UPS 19: Maintenance bypass switch for 6k to 20K 20: N + X parallel redundancy and capacity expansion for 6k to 20K