Emerson drive voltage is too low to repair fault
A textile mill SP2403 driver, there is a time when there is a fault OV, which means that the input voltage is overvoltage.
Emerson SP Series busbar inspection is rarely problematic. Bus detection should also be treated separately:
When the power is on, the bus overvoltage will be reported;
2.Bus overvoltage is reported during operation.
If you power on, you can report the bus overvoltage, you can look at 0505 first, this real-time voltage must exceed 780 before the overvoltage alarm. The bus voltage in the field, showing 562, is normal. In order to further determine, change the power supply to auxiliary power supply, online power supply, bus detection normal, and then disconnect the power supply, use a multimeter to directly detect whether the bus disappear voltage and monitor the voltage is consistent,—— the data of comparison is very accurate, it seems that the fault point is not in the bus detection circuit.
After reorganizing my thinking, I felt that the fault point should still be on the power supply circuit. When the power supply voltage of the motherboard was measured, it was found that the voltage was 28V, which was a bit high. However, the general motherboard power supply range is relatively wide, and it can work normally between 20 and 30V (such as KEB). Check the capacitance first, the capacity deviation is not large, then check the resistance, find that the impedance is not right, try to jump the power supply voltage, use external DC power supply, the fault disappears immediately. It seems that the problem has been found, continue to push backwards, and finally a voltage regulator IC has failed, resulting in the power supply cannot be stabilized, resulting in an input OV fault alarm. Replace the IC of the same model and repair the whole machine.