1000 point inverter welder maintenance data

1. Causes of inverter welding machine failure

Because inverter welding machine belongs to electronic products, its complex structure and technology, coupled with the instability of some components, will make the welding machine malfunction.

Common reasons for failure are as follows:

a.

Transportation vibration

b.

The operating voltage exceeds the use range.

c.

too many

d.

misemploy

e.

The use environment is harsh, such as high temperature and high humidity.

f.

Poor quality of individual components.

2. Common maintenance methods of inverter welding machine

1.

Resistance method.

Is to use a multimeter to measure the resistance of each device in the circuit. Check the circuit for short circuit or open circuit. Such as whether the resistor is damaged, whether the capacitor is lost, whether the transistor is damaged by breakdown, short circuit or open circuit, etc. This method is the simplest and most commonly used, and is suitable for the initial fault judgment of resistors, capacitors, inductors, transistors, integrated circuits, etc.

2.

Voltage method.

It is to measure whether the working voltage of each working point of the circuit is normal when the circuit is electrified. This method requires familiarity with the circuit. However, the measurement and judgment results will be more accurate.

3.

Replacement method.

It is a method to judge and eliminate faults by replacing some uncertain components in the circuit with good components. This method is generally used in machines that can roughly determine the fault location, and is generally used as a follow-up judgment method of resistance method.

4.

Waveform judgment method.

Under certain conditions, the working waveform of each working point can be observed by means of oscilloscope and other instruments, and the fault parts of the circuit can be separated from the waveform. This is the most intuitive fault analysis method, which is used to analyze some intractable diseases.

3. Common faults and treatment of inverter welding machine

1. Boot protection

There are several reasons for this failure:

A.

The field tube is damaged, which is overcurrent protection.

B.

The secondary rectifier tube is damaged, which is overcurrent protection.

C.

The medium board transformer is damaged, which is overcurrent protection.

D.

The temperature control switch is damaged, which belongs to false protection.

E.

The protection circuit of the control panel is damaged, which belongs to error protection.

When the protection circuit of the welding machine doesn't work, when the welding machine has overcurrent, it will cause the explosion of the machine. Pay special attention to whether the protection circuit is normal during maintenance.

Troubleshooting:

For the damage of field tube and secondary rectifier tube, the resistance of field tube is generally measured by resistance method, and whether there is short circuit or abnormal resistance between field tube and secondary rectifier tube. When judging whether the medium plate transformer is damaged, it is generally to unplug the transformer and see if there is any protection fault in the welding machine. If the medium board transformer is unplugged, there will be no protection fault, and it can be roughly judged whether the medium board transformer is damaged, but the premise of judging this fault is that the secondary rectifier tube is not damaged and the output of the welder is not short-circuited. The content of metalworking WeChat is good and worthy of attention. To judge the fault of the temperature control switch, just unplug the connecting wire of the temperature control switch on the control panel. If the fault disappears, it is caused by the temperature control switch. The fault of the protection circuit, when other faults are eliminated, the fault still does not disappear. When the protection lamp is still on, we can determine that the protection circuit is faulty. In order to eliminate this fault, the resistance method is generally used to measure whether the components of the protection circuit are normal. In order to repair the fault.

2.

No output

Cause analysis:

A.

There is something wrong with the power supply of the backplane (power board), and there is no 300-volt DC output.

B. the auxiliary power supply is damaged.

C.

There is no driving pulse.

D.

There is fault protection.

E.

The connecting wire inside the welding machine has dropped.

Troubleshooting:

The failure of bottom board (power board) is generally caused by the damage of some devices, such as main relay, auxiliary relay and thermistor. Inspection methods generally adopt resistance method and replacement method. If the auxiliary power supply is damaged, the components in the auxiliary power supply can also be measured by resistance method and replacement method. If possible, the working waveform of auxiliary power supply can be observed by waveform method to see if there are hidden faults. After eliminating the above faults, it can be judged whether there is a fault without driving pulse, which involves whether there is protection. In some welding machines, there is also a welding torch switch circuit, and its abnormal operation will also lead to no output pulse. The content of metalworking WeChat is good and worthy of attention. For this problem, it is generally necessary to observe the driving pulse with the help of an oscilloscope. In this kind of fault, we can also check the power supply of each part of the welding machine by voltage method to help eliminate the fault.

3. No high frequency

This fault is aimed at argon arc welding machine and cutting machine.

Fault analysis: a.

No output leads to no high frequency. B.

There is no high frequency circuit damage caused by high frequency. C.

There is no high frequency caused by the falling or loosening of the connecting wire.

Troubleshooting:

For no high frequency caused by no output, high frequency can be output by repairing no output fault. When the high-frequency circuit is damaged, resistance method and replacement method can be generally used to detect the high-frequency circuit, find out the damaged device and repair the fault. If the fault is caused by the falling of the connecting cable, check the connecting cable to ensure that the connecting cable is connected normally before troubleshooting.

Add some simple analysis and solving skills.

1. Fault symptom: abnormal voltage indicator light is on.

Cause 1: The switch contacts are out of synchronization due to slow starting action.

Solution: You can close it and then open it again.

Reason 2: The power supply voltage is out of phase or the input voltage is too high or too low (greater than 440V or less than 320V), which is beyond the normal working range of the welder.

Solution: Measure the input voltage with a multimeter. Is AC three-phase 380V normal?

2. Fault symptom: The fan does not turn, and the abnormal voltage indicator light is on.

Cause: The power supply is out of phase.

Solution: Measure the input voltage with a multimeter. Is AC three-phase 380V normal?

3. Fault symptom: The fan does not turn, and the abnormal temperature indicator light is on.

Cause: The fan was damaged, which caused the IGBT module to heat up.

Solution: Open the chassis and replace the fan.

4. Fault symptom: The indicator of abnormal temperature is on.

Reason: If the rated load rate is exceeded and the IGBT temperature exceeds the normal use range, it will automatically give an alarm.

Solution: it can be started with no load, so that the fan can automatically dissipate heat, and the IGBT will return to normal work after cooling down.

In order to avoid the IGBT from overheating, please use it according to the rated load rate indicated in the manual.

5. Fault phenomenon: The indicator light of abnormal current is on.

Reason 1: This phenomenon often occurs in the case of no load or low welding current. It shows that the over-current alarm link is too sensitive.

Solution: Change the circuit board.

Reason 2: Working in high current state for a long time, the abnormal current indicator light will light up. In standby mode, please turn it off immediately and restart it after the temperature drops. If it still can't return to normal after restarting, the IGBT or main transformer in the welding machine has been damaged.

6. Fault phenomenon: The indicated value of no-load voltage of voltmeter is low (less than 65V) after starting.

Cause 1: The indication of voltmeter is biased.

Solution: Measure the voltage between (+) and (-) quick connectors with a multimeter in the DC voltage range, which is between 65V and 75V. It shows that the no-load output of this machine is normal. Replace the display voltmeter head.

Reason 2: AC contactor does not suck.

Solution: Find out the reason and replace the corresponding parts.

Reason 3: IGBT is open.

Solution: Measure the voltage between (+) and (-) quick connectors with a multimeter, which is between 30V and 45V. It shows that an IGBT tube in the full-bridge inverter circuit is turned on, and the damaged module is found and replaced with a new one.

7. Fault phenomenon: The displayed voltage value is 0 when there is no load.

Reason one: the voltmeter lead is broken or the display meter is broken.

Solution: Measure the voltage (+) and (-) between two quick connectors with a multimeter between 65V and 75V. It shows that the no-load output of this machine is normal. After shutdown, use a multimeter to measure the two leads of the voltmeter to the (+) and (-) positions respectively. The two quick connectors are connected, indicating that the leads are not broken. Maybe the voltmeter is broken. Change the meter. The content of metalworking WeChat is good and worthy of attention.

Cause 2: Circuit board components are damaged.

Solution: Find out the damaged circuit board and replace it.

Reason 3: IGBT is damaged.

Solution: Turn off the power supply and remove the IGBT tube to determine whether the IGBT tube is damaged. And replace it.

8. Failure phenomenon; Unstable current or poor welding effect

Reason 1: Some parts of the welding machine have poor contact. (For example: loose lead end of IGBT. The balance resistance at both ends of electrolytic capacitor falls off, etc. )

Solution: Open the chassis, find the fault point and reconnect.

Reason 2: The "Thrust Current" and "Spark Current" knobs on the panel are not properly adjusted.

Solution: During general welding, please adjust the knobs of "Thrust Current" and "Arc Current" to the minimum position.

Reason 3: During manual arc welding, the current of WSM pulsed argon arc welding machine is unstable.

Solution: Please check the "DC" and "pulse" switches on the front panel, and point to "DC" when starting the arc manually. Otherwise, oscillation will occur.

9. Maintenance steps of common electric welding machines (according to different operation modes of different electric welding machines):

First, the IGBT exploded, and the resistance of the main board LM3 17 to the ground became larger, which led to the IGBT explosion after the voltage of 22V increased. The IGBT was replaced, and the resistor116w was changed to 1/8W, which was a design defect, so two sets were repaired and used for five years without breaking down!

Second, when the current has current, sometimes no current adjustment doesn't work! Check the 380V0.56UF explosion of commutating electrodeless capacitor, replace it normally, and repair 3 sets.

Three, welding machine no current or small output other normal, check the panel remote control and machine control switch is bad, repair 4 sets.

4. If there is no output, check whether the IR9630, IR630 and 4 MOS on the main board of the welding machine are broken, and two are replaced and two are repaired.

5. The overheated fan is broken!