1. Power on protection.
The causes of this failure are as follows:
A. Field tube damage, for the overcurrent protection.
B. Secondary rectifier tube damage, for overcurrent protection.
C. Transformer damage in the board, for overcurrent protection.
D. Temperature control switch damage, for the error protection.
E. The control board protection circuit is damaged, for the error protection.
When the welder protection circuit is not working, the welder can cause an explosion when there is overcurrent. Pay special attention to whether the protection circuit is normal when maintaining the machine.
Troubleshooting:
For damage to the site piping and secondary rectifier piping, the resistance of the site piping is usually measured using the resistance method to see if there is a short circuit or if the resistance of the site piping and secondary rectifier piping is abnormal. In determining whether the intermediate board transformer is damaged, the transformer is usually unplugged to see if the welder still has a protection fault. If the intermediate plate transformer is unplugged, there will be no protection fault, so it can be generally determined whether the intermediate plate transformer is damaged.
However, the prerequisite for determining the fault is that the secondary rectifier tube is not damaged and the output of the welder is not short-circuited. The content of the metal processing micro letter is good and worthy of attention. In order to determine the fault of the temperature control switch, simply unplug the connecting wire of the temperature control switch on the control board. If the fault disappears, the fault is caused by the temperature control switch. Fault in the protection circuit. When eliminating other faults, the fault still does not disappear. When the protection light is still on, we can be sure that the protection circuit is faulty. Eliminating this fault usually uses the resistance method to measure whether the components of the protection circuit are normal. To fix the fault.
2. No output.
The causes of this failure are as follows:
A. The bottom board (power supply board) does not have 300 volts DC output.
B. Auxiliary power supply is damaged.
C. No drive pulse.
D. Failure to protect.
E. The internal connecting wire of the welder is off.
Troubleshooting:
Base board (power board) failure is generally caused by damage to certain devices, such as the main relay, auxiliary relay, thermistor, etc.. The inspection method generally uses the resistance method and the replacement method. If the auxiliary power supply is damaged, you can also use the resistance method and the replacement method to measure whether the components in the auxiliary power supply are damaged. If possible, you can use the waveform method to observe the operating waveform of the auxiliary power supply to see if there are hidden faults. After eliminating the above faults, you can determine if there is no drive pulse fault, which involves the presence or absence of protection. In some welding machines, there are gun switch circuits, and their abnormal operation can also occur without output pulses. The content of the metal handling microscope is good and worthy of attention.
For this problem, an oscilloscope is usually used to observe the drive pulse. In this fault, we can also use the voltage method to check the power supply to the various parts of the welder to help eliminate the fault.
3. No high frequency.
Failure of tig welding and cutting machine.
The causes of this failure are as follows:
A. No output leads to no high frequency.
B. No high frequency due to damage to the high frequency circuit.
C. Connection wire off or loose lead to no high frequency.
Troubleshooting:
For no high frequency caused by no output, you can output high frequency by repairing no output fault. When the high frequency circuit is damaged, the resistance method and replacement method can be used to test the high frequency circuit, and the damaged equipment can be found to repair the fault. If the connection line is off to cause the fault, check the connection line to ensure that the connection line is connected properly and the fault is eliminated.
