... -circuit,over-voltage,low-voltage,over-heating,etc.5.Easy to check with inverter with consice LED indication that can be upgrade ... commercial inversion state:60/50±0.5Voltage range(Vac)100/110/120/127/220/230+10%(Auto=sensing)Transfer TimeTupical:5ms ... 120% of nomarl value for 30 second,IPS automatically resume work if overload comes back to rated load.BatteryTypeSealed,maintenance-free lead ...