Huabao Golden Warrior UPS Power 2020-06-18

What are the common faults of UPS uninterruptible power supply? How to solve these faults?

Problem 1: UPS output is normal when there is mains power, but the buzzer beeps long and no output when there is no mains power. Failure analysis: Judging from the phenomenon that the battery and inverter are partially faulty, you can check according to the following procedures: ----Check the battery voltage to see if the battery is under-charged, if the battery is under-charged, check whether the battery itself is faulty or charging circuit failure. -----If the operating voltage of the battery is normal, Chifeng Yuasa Battery Factory checks whether the inverter drive circuit works normally. If the output of the drive circuit is normal, the inverter is damaged. ----If the inverter drive circuit is not working properly, check whether the waveform generating circuit has PWM control signal output. If there is a control signal output, it means that the fault lies in the inverter drive circuit. ----If the waveform generating circuit has no PWM control signal output, check whether its output is blocked due to the work of the protection circuit, if so, find out the cause of protection; ----If the protection circuit is not working and the working voltage is normal, and the waveform No PWM waveform output of the generating circuit means that the waveform generating circuit is damaged-the above troubleshooting sequence can also be reversed, sometimes the fault can be found faster.

Problem 2: The battery voltage is low, but the battery voltage still cannot be charged after charging for more than ten hours. Fault analysis: Judging from the phenomenon that the battery or the charging circuit is faulty, you can check according to the following steps: --Check whether the input and output voltage of the charging circuit is normal; --If the input and output voltage of the charging circuit is normal, disconnect the battery and test again. Abnormality means that the charging circuit is faulty;-if the input and output of the charging circuit are normal after the battery is disconnected, it means that the battery has been damaged due to long-term uncharged, over-discharged, or expired life.

Problem 3: A pair of power amplifier transistors of the inverter power stage are damaged. After replacing the transistors of the same model, the reason is that the current is too large. The reasons for the excessive current are:-the overcurrent protection fails. When the inverter output over-current, the over-current protection circuit does not work;-the pulse width modulation (PWM) component fails, the two complementary waveforms of the output are asymmetrical, one has a long conduction time, and the other conduction time Short, make the two arms work unbalanced, or even conduct the two arms at the same time, causing damage to the two tubes;-The power tube parameters are quite different. At this time, even if a symmetrical waveform is input, the output will be asymmetrical. This waveform is caused by the output transformer. Bias magnetism, that is, unbalanced magnetic flux. Accumulation will cause the transformer to saturate and the current will increase sharply.

Question 4: After the UPS is turned on, there is no display on the panel, and the UPS does not work. Fault analysis: Judging from the fault phenomenon, the fault is in the mains input, battery and mains detection part and the battery voltage detection circuit: - check whether the mains input fuse is burned; - if the mains input fuse is intact, check whether the battery insurance Burned out, because some UPS will turn off all the output and display of the UPS when the battery voltage is not detected by itself;--If the battery insurance is intact, Chifeng Tangqian Battery Factory will check whether the mains detection circuit is working properly, if the mains detection When the circuit is not working properly and the UPS does not have the function of starting without mains, the UPS will also turn off all outputs and displays. --If the city detection circuit works normally, check whether the battery voltage detection circuit is normal.

Question 5: When the UPS is connected to the mains, every time the UPS is turned on, the relay repeats the sound, the battery voltage low indicator on the UPS panel is on and the buzzer beeps for a long time. According to the above failure phenomenon, it can be judged that the failure is caused by the battery voltage being too low, which causes the UPS to start unsuccessfully. Remove the battery, first perform equalizing charge (all batteries are charged in parallel), if it is still unsuccessful, only replace the battery.

Problem 6: A backup UPS works normally when there is mains power. When there is no mains power, the inverter has output, but the output voltage is low, and the transformer makes louder noise. Fault analysis: The inverter has output indicating that the final drive circuit is basically normal, and the noise of the transformer indicates that the two arms of the push-pull circuit are asymmetrical. The detection steps are as follows: --check whether the power is normal; --if the power is normal, check the pulse Whether the output signal of the wide output circuit is normal;-If the output of the pulse width output circuit is normal, check whether the output of the drive circuit is normal.

Problem 7: Turn on the UPS when the mains power supply is normal, the inverter working indicator flashes, and the buzzer emits intermittent beeps. The UPS can only work in the inverter state and cannot be converted to the mains working state. Failure analysis: the conversion of inverter power supply to mains power supply cannot be performed, indicating that the conversion part of inverter power supply to mains power supply has failed, and the key inspections are:-whether the mains input fuse is damaged;-if the mains input fuse is intact, Check whether the output of the mains rectifier and filter circuit is normal; --If the output of the mains rectifier and filter circuit is normal, check whether the mains detection circuit is normal; --If the mains detection circuit is normal, then check the control output of the inverter power supply to the mains power supply conversion Is it normal?

Question 8: When the load of the backup UPS is close to full load, the mains power supply is normal, and the battery fuse is blown when the battery is supplying power. Fault analysis: the battery fuse is blown, indicating that the battery supply current is too large. The detection steps are as follows: --whether the inverter has broken down; --whether the battery voltage is too low; --if the battery voltage is too low, check whether the battery charging circuit is normal ;--If the battery charging circuit is normal, check whether the battery voltage detection circuit works normally.

Question 9: UPS can only be powered by city power and cannot be converted to inverter power. Failure analysis: the conversion from mains to inverter power supply cannot be carried out, indicating that there is a failure in the conversion part of mains to inverter power supply. The key inspections are:-whether the battery voltage is too low and whether the battery fuse is intact;-if the battery part is normal, check Whether the battery voltage detection circuit is normal; if the battery voltage detection circuit is normal, check whether the control output from the mains to the inverter power supply is normal.