High voltage sharp pulse refers to a voltage with a peak value of 6000V and a duration ranging from one thousandth of a second to one half of a cycle (10ms). This is mainly caused by lightning strikes, arc discharges, static discharges, or switching operations of large electrical equipment.

When the mains power is normal at 380Vac, there is a DC voltage in the DC main circuit, which is supplied to the DC-AC AC inverter and outputs a stable 220V or 380Vac AC voltage. At the same time, the mains power is rectified to charge the battery. When the mains power is under voltage or suddenly loses power, the battery pack feeds power to the DC circuit through an isolation diode switch. There is no switching time from grid power to battery power. When the battery energy is about to run out, the uninterruptible power supply emits an audible and visual alarm, and stops the inverter operation at the lower limit of battery discharge, with a long beep alarm.

The uninterruptible power supply also has an overload protection function. When an overload occurs (150% load), it jumps to the bypass state and automatically returns when the load is normal. When a serious overload occurs (exceeding 200% of the rated load), the uninterruptible power supply immediately stops the inverter output and jumps to the bypass state. At this time, the front input air switch may also trip. After eliminating the fault, as long as the switch is turned on and restarted, the operation will resume.