UPS uninterruptible power supply troubleshooting methods

Source: 2020 - 03 - 25 11:30 hits: 1 time UPS uninterruptible power supply troubleshooting methods. UPS power supply output normal, buzzer is longer, no power supply output. Failure analysis: look from the phenomenon, this is part of the battery and inverter fault, can follow the steps below to check: check the battery voltage, to see if the battery owes to charge, if the battery owes to charge, to check the battery itself is a fault or charging circuit malfunction. If the battery voltage is normal, check whether the inverter drive circuit is working properly, if the output driver circuit is normal, the damage of inverter. If the operation of the inverter drive circuit check if there is a PWM control signal output waveform generating circuit. If there is a control signal output, then the fault in the inverter driving circuit. If no PWM control signal output waveform generating circuit, check whether the output due to the protection circuit block, if yes, identify the reasons for protection; Don't work if the protection circuit and voltage is normal, no PWM waveform output circuit and waveform, the waveform generating circuit damage. The above troubleshooting sequence can also be reversed, and sometimes can find fault more quickly. 2, the battery voltage is low, but the boot charging more than 10 hours, the battery voltage is not charging. Failure analysis: judging from phenomenon, battery or charging circuit fault inspection according to the following steps: check whether the charging circuit input and output voltage is normal; If the normal charging circuit input, the output is unusual, the battery is disconnected for retest, if still is abnormal, the charging circuit fault; After the battery disconnect, charging circuit input and output is normal, indicating the battery is not charging for a long time, discharge or has reached the service life. 3, inverter power level of a pair of amplifier transistor is damaged, replacement of the same type transistor, burn out after running for a period of time. The reason is that current is too large, an electrical current for the following reasons: overcurrent protection failure. When the inverter output produced flow, over-current protection circuit does not work. Pulse width modulation ( 脉宽调制) Component failure, the output waveform of two complementary asymmetry, a long lead time, another short lead time, the balance of two arms didn't work, even lead at the same time, two arms two pipe damage; Power tube parameters vary widely, even if the input symmetric waveform, the output will be asymmetric waveform through the output transformer, magnetic bias, the flux imbalance, the accumulation of saturated transformer and current shock, burning out the power tube, and a burnt out, the other is burnt out. 4. UPS after start-up, panel did not show, UPS is not working. Failure analysis: from the point of failure phenomenon, failure is in the test section of the power input, battery and power supply and battery voltage detection circuit: check whether the power input the fuse is burnt out; If the main power input fuse in good condition, please check whether the battery insurance burn out, because when the battery voltage cannot be self-checking, some UPS will be shut down all of the output and the display of the UPS. If the battery is in good condition insurance, check whether the power detection circuit is working properly. If the mains detection circuit work is not normal, UPS no mains start function, UPS will be shut down all of the output and display. If the utility test circuit works well, check the battery voltage test circuit is normal. 5. In the case of connected to the mains, each open UPS, relay will hear repeated movements, the battery voltage is too low, UPS panel will have bright lights, buzzer will always bright. According to the above failure phenomenon, can determine fault is due to the battery voltage is too low, the UPS start to fail. Take out the battery, first of all to balance charge ( All the batteries in parallel charging) , if still not success, only change the battery. 6. Have a power supply spare UPS work, without the power inverter output, but the low output voltage, large transformer noise. Failure analysis: basic normal inverter output indicates that the final drive circuit, transformer noise show that push-pull circuit work asymmetric two arms.