... 2)4 steps AVR, 220v+_10% 3)super wide input frequency range from 40HZ-70HZ Home UPS function :Uninterruptible power supply ... from 40HZ-70HZ,can accept all kinds of great frequency generator,such as diesel engine .etc.4) protections against output short- ... tube-lights, TV sets, air-condition, fans, refrigerators, motors, wind generator, solar system and so on,8) 4 steps AVR, 220v ...