Some people may think that UPS power failures are usually due to internal issues and blindly search for problems with various components of the UPS itself. In fact, during the operation of the UPS power supply, the connected mains power can also cause UPS failures. Due to the connected mains power, it is generally a system that not only supplies power to UPS, but also to other large equipment. Of course, some human or natural disasters can also cause UPS failures. There are many reasons for the occurrence of faults, which can be analyzed from the following points:
1.When large equipment is shut down, the mains system may experience a sudden disappearance of high voltage, causing the output voltage to exceed the UPS rated value for one or several cycles, which can easily lead to UPS failure.
2. Due to arc discharge or natural disasters (lightning), the peak voltage of the mains system can reach a very high level, making it difficult for the UPS power supply to respond. In this case, it is difficult to repair the UPS failure within one ten thousandth of a second or relatively longer.
3. The sudden start of a large electric motor causes the effective voltage of the mains system to be lower than about 80% of the rated value of the UPS, making it difficult for the UPS power supply to operate in this low voltage state.
4. Due to the unstable operation of the generator, the frequency of the mains system will also constantly change, sometimes even exceeding tens of thousands of hertz. It can be imagined that this is not suitable for the normal operation of UPS.
5. Some special equipment such as relays, microwave radiation, etc. may have interference similar to radio frequency, electromagnetic, or other high frequencies, which can cause UPS to malfunction.
6. The most important point is that interruption of the mains power is absolutely allowed for a long time. Sometimes, when the UPS malfunctions, it may be due to a problem with the battery part. However, circuit breakers tripping on the line and faults in the mains power system can affect the UPS to varying degrees. Scientifically identifying the cause of UPS problems can facilitate diagnosis by maintenance personnel and fundamentally solve the problem.