Detailed explanation of UPS uninterruptible power supply common faults and solutions

Autore: Iflowpower – Fornitore di stazioni di alimentazione portatili

Question 1: When there is a city time, the UPS output is normal, and the buzzer is long when there is no market, no output. Fault Analysis: From the phenomenon, it is determined that the battery and the inverter partial fault can be inspected: circuit failure. ----.

---- If the inverter drive circuit is not working properly, check that the waveform has a circuit without the PWM control signal output. If there is a control signal output, the fault is in the inverter drive circuit. ---- If the waveform has no PWM control signal output, check whether its output is blocked due to the protection circuit, if there is a protection reason; ---- If the protection circuit does not work, the operating voltage is normal, and the waveform There is no PWM waveform output of the circuit, indicating that the waveform is corrupted ---- The order of the above tribute is also possible, sometimes it can be discovered faster.

Question 2: The battery voltage is low, but the boot charging is more than ten hours, the battery voltage is still can't be filled. Fault analysis: Judging from the phenomenon as a battery or charging circuit failure, it can be checked as follows: - Check if the input and output voltage of the charging circuit is normal; - If the charging circuit is input is normal, the output is not normal, disconnect the battery and then measure, if still It is not normal to charge the charging circuit;. Question 3: Inverter power level pair of power amplifier transistors, after replacing the same model transistor, the reason for running for a period of time and burning is too large, and the cause of excessive current is: - overcurrent protection failure.

When the inverter outputs an overcurrent, the overcurrent protection circuit is not used; - pulse width modulation (PWM) component fault, the output two complementary waveforms are asymmetrical, one is on time, while another on time Short, make the two arms unbalanced, even the two arms are turned on simultaneously, causing two tube damage; - The power tube parameter is large, even if the symmetrical waveform is input, the output will be asymmetric, the waveform is output transformer, resulting Gas magnetic, magnetic flux is unbalanced, accumulating the transformer to be saturated, the current increases, burns bad power tube, and one burning, the other also burns bad problems 4: UPS is turned on, there is no display on the panel UPS does not work. Fault Analysis: Judging from the fault phenomenon, its fault is in the mains input, battery and market electrical testing circuit: - Check if the city's electric input fuse is burned; - If the market is intact, check whether the battery insurance is inspected Burning, because some UPS will close all the output and display of the UPS when the battery is self-test; The circuit work is not working properly and the UPS does not have a market-free function, and the UPS will also turn off all outputs and display. - If the city test circuit is working properly, check whether the battery voltage detecting circuit is normal.

Problem 5: In the case of accessing the mains, each time the UPS is opened, he will hear the repeated action sound of the relay, the UPS panel battery voltage is too low, the light is bright and the buzzer is long. According to the above fault phenomenon, it can be judged that the fault is that the battery voltage is too low, resulting in unsuccessful UPS startup. Remove the battery, advance, balance charging (all batteries are connected in parallel), if it is still unsuccessful, only replaceable batteries.

Question Six: A backup UPS is working properly, no market is output, but the output voltage is low, and the transformer has a large noise. Fault Analysis: Inverter Output Description The end-level driving circuit is basically normal, and the transformer has noise indicates that the two arm of the push-pull circuit is asymmetric. The test steps are as follows: - Check whether the power is normal; - Normal power, then check the pulse Wide output circuit output signal is normal; - If the pulse wide output circuit outputs normally, check whether the output of the drive circuit is normal.

Question 7: Open the UPS when the power supply is normal, the inverter work indicator flashes, the buzzer makes an intermittent scream, and the UPS can only work in the inverter, and cannot be converted to the main state of the city. Fault Analysis: Inverter power supply to the market, indicating that the inverter power supply has failed to the market power supply conversion section, and it is necessary to test whether the motor input fuse is damaged; - If the main input fuse is intact, Check that the output of the city electricity stream filter circuit is normal; Is it normal?. Question 8: When the backup UPS is close to the full load, the main power supply is normal, and the battery fuse is blown when the battery is powered.

Fault Analysis: Battery fuse blows, indicating that the battery supply current is too large, the detection step is as follows: - The inverter breaks down; - whether the battery voltage is too low; - If the battery voltage is too low, it will detect whether the battery charging circuit is normal. If the battery charging circuit is normal, the operation of the battery voltage detection circuit is normal. Question Nine: UPS can only be powered by the main electricity and cannot be converted to inverter power.

Fault Analysis: Cannot perform the market-electrical inverter power supply conversion, indicating that the city's electricity inverter power supply conversion section has failed, and it is necessary to test whether the battery voltage is too low, whether the battery fuse is intact; - If the battery is normal, check Whether the battery voltage detecting circuit is normal; if the battery voltage detecting circuit is normal, then check whether the market-oriented inverter power conversion control output is normal.