Welding inverter AIS 250 circuit. How to repair a welding inverter with your own hands. Welding current is not adjustable

Hi all!!! The other day a welding inverter was brought in for repair; perhaps my note about this repair will be useful to someone.

This is not the first welding machine that had to be made, but in one case the malfunction manifested itself like this: I turned on the inverter to the network... and boom, the circuit breakers in the electrical panel were knocked out. As the autopsy showed, the output transistors were broken in the welder, after replacement everything worked.

But in this case, everything was somewhat different; according to the owner, the device sometimes stopped cooking, although the power indicator was on. These guys opened the case themselves - they tried to determine the malfunction and noticed that the inverter reacted to the bending of the board, i.e. by bending it I could earn it. But when the welding inverter came to me, it no longer turned on at all, even the power indicator did not light up.

Welding inverter does not turn on

“Titan - BIS - 2300” - this is the model of inverter that was sent for repair, the circuitry is the same as a welding machine of similar power “Resanta” and, as I assume, many other inverters. You can view and download the diagram

This welding machine uses a switching power supply to power low-voltage circuits, and it was precisely this that was faulty. The UPS is made on a PWM controller UC 3842BN. Analogues - domestic 1114EU7, imported UC3842AN differs from BN only in lower current consumption, and KA3842BN (AN). The UPS diagram is below. (Click on it to enlarge) The voltages that were produced by the already working UPS are marked in red. Please note that voltages of 25V should not be measured relative to general minus, namely from points V1+,V1- and also V2+,V2- they are not connected to the common bus.

The UPS switch is made on a transistor, field switch 4N90C. In my case, the transistor remained intact, but the microcircuit required replacement. There was also a break in resistor R 010 - 22 Om/1Wt. After this the power supply started working.

However, it was too early to rejoice, having measured the voltage at the output of the welder, it turned out that there was none, but in the mode idle move should be approximately 85 volts. I tried to move the board, remember from the owner’s words it had an effect, but nothing.

Further searches revealed the absence of one of the 25 volt voltages at points V2-, V2+. The reason is a break in the transformer winding 1-2. I had to unsolder the trans, I used a medical needle to release the leads.

In the transformer, one of the ends of the winding was broken from the terminal.

We carefully restore the connection using a suitable wire; it will not be superfluous to fix the restored connection with a drop of glue or sealant. I happened to have some polyurethane glue on hand and used it to check other conclusions and solder them if necessary.

Before installing the transformer, you should prepare the board so that it fits into place without effort. To do this, you need to clean the holes from any remaining solder; this can also be done with a needle from a syringe of a suitable diameter.

After installing the transformer, the welding inverter started working.

How to check the microcircuit

How to check a microcircuit without desoldering it from the board and what else to pay attention to.

You can partially check the microcircuit if you have a voltmeter and an adjustable stabilized constant voltage source. A signal generator and an oscilloscope are required for a complete test.

Let's talk about what is simpler. Before checking, be sure to turn off the inverter from the power supply. Next, from an external regulated power supply we supply a voltage of 16 - 17 volts to pin 7 of the microcircuit, this is the MS startup voltage. In this case, there should be 5 V at pin 8. This is the reference voltage from the internal stabilizer of the chip.

It should remain stable when the voltage on pin 7 changes. If this is not the case, the MS is faulty.

When changing the voltage on the microcircuit, keep in mind that below 10 V the microcircuit turns off and turns on at 15-17 volts. You should not increase the supply voltage of the MS above 34 V. There is a protective zener diode inside the microcircuit, and if the voltage is too high, it will simply break through.

Below is structural scheme UC3842.

Addition to this article: After some time they brought another device. Out of service due to falling on its side. This happened because during operation the screws holding the case became loose, and some were simply lost, so when dropped, the board played and touched the case with the mounting side. As a result of the short circuit, all 4 output transistors K 30N60HS Analogs G30N60A4D, G40N60UFD failed. After the replacement everything worked.

That's all! If you found this article useful, leave your comments and share with friends by clicking on the social network buttons.

Designed for periodic construction and repair work, produces manual arc welding piece electrodes (MMA). Ideal for welding work at the dacha, at home, in the garage. It is possible to weld in an environment of protective inert gas argon (TIG), at direct current with a non-consumable tungsten electrode. The circuit of the power part of the inverter is made on IGBT transistors (K40H603) and diodes 60F30. The control board on the PWM controller and operational amplifier allows you to use the “HOT START”, “ANTI-STICK”, “ARC FORCE” functions. power unit ELITECH IS 200 on the microcircuit and MOSFET transistor provides the necessary voltage for the operation of the inverter electronic circuit.

Supply voltage - 220V
Open circuit voltage – 85V
Welding current range - 10-180A
Load duration at current 180A - 60%
Load duration at current 100A - 100%
The diameters of the electrodes used are 1.6-5mm

Repairs, despite their complexity, in most cases can be done independently. And if you have a good understanding of the design of such devices and have an idea of what is most likely to fail in them, you can successfully optimize the costs of professional service.

Purpose of the equipment and features of its design

The main purpose of any inverter is to generate direct welding current, which is obtained by rectifying high-frequency alternating current. The use of high frequency alternating current, converted by means of a special inverter module from a rectified network one, due to the fact that the strength of such current can be effectively increased to the required value using a compact transformer. It is this principle put into operation that allows such equipment to have compact dimensions with high efficiency.

Welding inverter circuit that defines it specifications, includes the following main elements:

a primary rectifier unit, the basis of which is a diode bridge (the task of such a unit is to rectify alternating current coming from a standard electrical network);
inverter block, the main element of which is a transistor assembly (it is with the help of this block D.C., arriving at its input is converted into an alternating variable, the frequency of which is 50–100 kHz);
a high-frequency step-down transformer, on which, by lowering the input voltage, the output current significantly increases (thanks to the principle of high-frequency transformation, a current of up to 200–250 A can be generated at the output of such a device);
output rectifier assembled on the basis of power diodes (the task of this inverter block is to rectify alternating high-frequency current, which is necessary for welding work).

The welding inverter circuit also contains a number of other elements that improve its operation and functionality, but the main ones are those listed above.

Features of maintenance and repair of inverter devices

Repairing an inverter-type welding machine has a number of features, which is explained by the complexity of the design of such a device. Any inverter, unlike other types of welding machines, is electronic, which requires specialists involved in its maintenance and repair to have at least basic radio engineering knowledge, as well as skills in handling various measuring instruments– voltmeter, digital multimeter, oscilloscope, etc.

In progress Maintenance and repair, the elements of which it consists are checked. This includes transistors, diodes, resistors, zener diodes, transformer and choke devices. The peculiarity of the inverter design is that very often during its repair it is impossible or very difficult to determine which element failure caused the malfunction.

In such situations, all details are checked sequentially. To successfully solve such a problem, you must not only be able to use measuring instruments, but also have a fairly good understanding of electronic circuits Oh. If you do not have such skills and knowledge, at least at an initial level, then repairing a welding inverter with your own hands can lead to even more serious damage.

Realistically assessing your strengths, knowledge and experience and deciding to take on do-it-yourself repair inverter-type equipment, it is important not only to watch a training video on this topic, but also to carefully study the instructions in which manufacturers list the most typical faults welding inverters, as well as ways to eliminate them.

Factors leading to failure of the welding inverter

Situations that can cause the inverter to fail or lead to disruptions in its operation can be divided into two main types:

associated with incorrect choice of welding mode;
caused by failure of device parts or their incorrect operation.

The method for identifying an inverter malfunction for subsequent repair comes down to sequential execution technological operations, from the simplest to the most complex. The modes in which such checks are performed and what their essence is are usually specified in the equipment instructions.

If the recommended actions do not lead to the desired results and the operation of the device is not restored, most often this means that the cause of the malfunction should be sought in the electronic circuit. The reasons for the failure of its blocks and individual elements may be different. Let's list the most common ones.

In inner part moisture has penetrated the device, which can happen if the device body is exposed to precipitation.
Dust has accumulated on the elements of the electronic circuit, which leads to a disruption in their proper cooling. The maximum amount of dust enters the inverters in cases where they are operated in very dusty rooms or on construction sites. To avoid this condition, the inside of the equipment must be cleaned regularly.
Failure to comply with the on-time (ON) can lead to overheating of the electronic circuit elements of the inverter and, as a consequence, to their failure. This parameter, which must be strictly observed, is indicated in technical passport equipment.

Common faults

The most common faults encountered when operating inverters are the following.

Unstable burning of the welding arc or active spattering of metal

This situation may indicate that the current strength for welding is incorrectly selected. As is known, this parameter is selected depending on the type and diameter of the electrode, as well as on the speed of welding work. If the packaging of the electrodes you are using does not contain recommendations on the optimal current value, you can calculate it using a simple formula: per 1 mm of electrode diameter there should be 20–40 A of welding current. It should also be taken into account that the lower the welding speed, the lower the current should be.

Electrode sticking to the surface of the parts being connected

This problem can be due to a number of reasons, most of which are due to low supply voltage. Modern models inverter devices operate at reduced voltage, but when its value drops below the minimum value for which the equipment is designed, the electrode begins to stick. A drop in voltage at the equipment output can occur if the device blocks are in poor contact with the panel sockets.

This reason can be eliminated very simply: by cleaning the contact sockets and more tightly fixing the electronic boards in them. If the wire with which the inverter is connected to the electrical network has a cross-section of less than 2.5 mm2, this can also lead to a voltage drop at the input of the device. This is guaranteed to happen even if such a wire is too long.

If the length of the supply wire exceeds 40 meters, it is almost impossible to use an inverter for welding, which will be connected with its help. The voltage in the supply circuit may also drop if its contacts are burnt or oxidized. Common cause electrode sticking is no longer enough quality training surfaces of the parts being welded, which must be thoroughly cleaned not only of existing contaminants, but also of oxide film.

Inability to start the welding process when the machine is turned on

This situation often occurs when the inverter device overheats. The control indicator on the device panel should light up. If the glow of the latter is barely noticeable, and the inverter does not have a sound warning function, then the welder may simply not be aware of overheating. This state of the welding inverter is also typical when the welding wires break or spontaneously disconnect.

Spontaneous shutdown of the inverter when welding

Most often, this situation occurs when the supply voltage is turned off. circuit breakers, whose operating parameters are incorrectly selected. When working with an inverter device, circuit breakers rated for a current of at least 25 A must be installed in the electrical panel.

Inability to turn on the inverter when turning the toggle switch

Most likely, this situation indicates that the voltage in the supply network is too low.

Automatic inverter shutdown during prolonged welding

Most modern inverter devices are equipped with temperature sensors that automatically turn off the equipment when the temperature in its internal part rises to a critical level. There is only one way out of this situation: give the welding machine a rest for 20–30 minutes, during which it cools down.

How to repair an inverter device yourself

If after testing it becomes clear that the cause of malfunctions in the operation of the inverter apparatus lies in its internal part, you should disassemble the housing and begin inspection electronic filling. It is quite possible that the reason lies in poor-quality soldering of the device parts or poorly connected wires.

A careful examination of electronic circuits will reveal faulty parts, which may be darkened, cracked, with a swollen body, or have burnt contacts.

During repairs, such parts must be desoldered from the boards (it is advisable to use a soldering iron with suction for this), and then replaced with similar ones. If the markings on faulty elements are not readable, then special tables can be used to select them. After replacing faulty parts, it is advisable to test the electronic boards using a tester. This is especially necessary if the inspection did not reveal elements that need to be repaired.

Visual inspection of the electronic circuits of the inverter and their analysis using a tester should begin with power block with transistors, since it is he who is the most vulnerable. If the transistors are faulty, then most likely the circuit that drives them (driver) has also failed. The elements that make up such a circuit also need to be checked first.

After checking the transistor block, all other blocks are checked, for which a tester is also used. Surface printed circuit boards It is necessary to carefully inspect them to determine the presence of burnt areas and breaks. If any are found, then you should thoroughly clean such places and solder jumpers on them.

If burnt or torn wires are found in the inverter filling, then during repairs they must be replaced with similar cross-sections. Although the diode bridges of the inverter rectifiers are quite reliable elements, they should also be tested using a tester.

The most complex element of the inverter is the key control board, the serviceability of which determines the performance of the entire device. Such a board is checked using an oscilloscope for the presence of control signals that are supplied to the gate buses of the key block. The final stage Testing and repairing electronic circuits of an inverter device should involve checking the contacts of all available connectors and cleaning them using a regular eraser.

Self-repair of such electronic device, as an inverter, is quite complex. It is almost impossible to learn how to repair this equipment simply by watching a training video; for this you need to have certain knowledge and skills. If you have such knowledge and skills, then watching such a video will give you the opportunity to make up for your lack of experience.

An inverter welder differs from a conventional welding machine in an easier and better welding process. However, malfunctions of the welding inverter, due to its more complex design, can be more serious and complex.

To determine the cause of a device failure, you need to diagnose it: check transistors, resistors, diodes, stabilizers, contacts, etc. Each device is supplied with detailed instructions with a description of the most common faults that you can fix yourself. However, very often, special equipment may be required to carry out repairs: ohmmeter, voltmeter, multimeter, oscilloscope. And you need to know how to use them. And in special cases, knowledge of electronics and the ability to work with electrical circuits are required. Therefore, if self-checking and eliminating simple faults described below does not lead to success, it is better to entrust the repair of the inverter apparatus to specialists in service center.

What are the types of inverter malfunctions?

There are several groups of breakdowns of welding inverters:

malfunctions arising due to non-compliance with the welding workflow standards specified in the instructions;
malfunctions arising as a result of incorrect operation or failure of device elements;
damage resulting from moisture, dust and foreign objects entering the device.

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Common faults that you can fix yourself

Let's look at some of the most common malfunctions of welding inverters:

To identify and eliminate the cause of the malfunction, the device body is opened and visual inspection its contents.

The welding arc burns unsteadily or the electrode spatters material heavily. The reason for this may lie in the wrong choice of current. The current must be appropriate for the type and diameter of the electrode and the speed welding process. If the current strength is not indicated on the electrode packaging, then you can start supplying current from 20-40 A for each millimeter of electrode diameter. When the welding speed is reduced, the current must also be reduced.
The electrode sticks to the material. This often happens due to low voltage in the network, the value of which is less than the minimum permissible when working with an inverter. The cause of electrode sticking can also be poor contact in the panel sockets, which can be eliminated by fixing the boards more tightly. Using an extension cord with a wire size smaller than 2.5 mm2 or with a wire that is too long (more than 40 m) may reduce the voltage. Burnt or oxidized contacts in an electrical circuit can also reduce voltage.
There is no welding process, while the device is connected to the network. In this case, you need to check the presence of mass on the part being welded. Also check the inverter cable for damage.
The device turns off spontaneously. The device is switched off when the transformer is connected to the network, after which its protection is triggered. The reason for this may be a short circuit in the voltage circuit. The protection can be activated not only when the wires are shorted to each other or to the housing, but also when there is a short circuit between the turns of the coils or a breakdown of the capacitors. To repair a hollow part, you first need to disconnect the transformer and find the fault, and then insulate or replace the damaged element.

If there is no welding when the machine is turned on, check the connection of the electrode holder cable.

In progress long work the device turned off. Most likely, this is not a breakdown, but an overheating of the inverter. You need to wait 20-30 minutes and then resume work. You should adhere to the rules for operating the device: do not overheat it, that is, take breaks in operation, connect the appropriate current values to it, do not use electrodes of too large diameters.

The transformer makes a loud noise and overheats. Perhaps the reason for this was an overload of the transformer, loosening of the bolts that tighten the sheets of the magnetic core, or a breakdown of the core fastening. Due to a short circuit between the magnetic core sheets or cables, the device can also make a loud noise. Tighten all fastening elements and restore cable insulation.

Welding current is poorly regulated. The reason for this may be a breakdown in the current regulation mechanism: a malfunction in the current regulation screw, a short circuit between the regulator mounts, a short circuit in the inductor, poor mobility of the secondary coils as a result of clogging, etc. Remove the casing from the inverter and examine the current regulation mechanism to identify the breakdown.

The welding arc breaks off abruptly, and it is impossible to ignite it; only sparks appear. Perhaps the problem lies in a breakdown of the high voltage winding, a short circuit between the wires, or a poor connection to the inverter terminals.

High current consumption at no load. The reason may be short circuit of the turns on the coil. It can be eliminated either by restoring the insulation or by completely rewinding the coil.

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If excessive spattering of the electrode metal occurs during welding, the cause may be an incorrectly selected value of the welding current.

If a burning smell and smoke appear from the device body, this may indicate a serious breakdown. IN in this case You may need qualified repairs at a service center.

To identify the malfunction, first disassemble the housing. Carry out a visual inspection of parts for damage, cracks, burnt contacts and swelling of capacitors. They also check the soldering points of parts and contacts on the inverter boards. Often the causes of malfunctions lie precisely in poor-quality soldering; they can be easily eliminated by re-soldering the parts.

All faulty parts should be removed and replaced with new ones corresponding to the given model of the device.

You can select parts in accordance with the markings indicated on the device body or in a special reference book.

You need to solder the parts using a soldering iron that has a suction, which will make the work convenient and fast.

Inverter welding machines are becoming increasingly popular among welders due to their compact size, low weight and reasonable prices. Like any other equipment, these devices can fail due to improper operation or due to design flaws. In some cases, you can repair inverter welding machines yourself by studying the design of the inverter, but there are breakdowns that can only be repaired in a service center.

Depending on the model, welding inverters operate both from a household electrical network (220 V) and from three-phase (380 V). The only thing that needs to be taken into account when connecting the device to a household network is its power consumption. If it exceeds the capabilities of the electrical wiring, then the unit will not operate if the network is drained.

So, the inverter welding machine includes the following main modules.

Primary rectifier block. This block, consisting of a diode bridge, is located at the input of the entire electrical circuit of the device. It is this that is supplied with alternating voltage from the mains. To reduce the heating of the rectifier, a heat sink is attached to it. The latter is cooled by a fan (supply fan) installed inside the unit housing. The diode bridge also has overheating protection. It is implemented using a temperature sensor, which breaks the circuit when the diodes reach a temperature of 90°.
Capacitor filter. It is connected in parallel to the diode bridge to smooth out alternating current ripples and contains 2 capacitors. Each electrolyte has a voltage reserve of at least 400 V, and a capacity of 470 μF for each capacitor.
Interference filter. During current conversion processes, electromagnetic interference occurs in the inverter, which can disrupt the operation of other devices connected to this electrical network. To remove interference, a filter is installed in front of the rectifier.
Inverter. Responsible for converting AC voltage to DC. Converters operating in inverters can be of two types: push-pull half-bridge and full bridge. Below is a diagram of a half-bridge converter with 2 transistor switches, based on devices of the MOSFET or IGBT series, which can most often be seen on inverter devices middle price category.
The circuit of a full bridge converter is more complex and already includes 4 transistors. These types of converters are installed on the most powerful welding machines and, accordingly, on the most expensive ones.
Just like diodes, transistors are installed on radiators for better heat removal from them. To protect the transistor unit from voltage surges, an RC filter is installed in front of it.
High frequency transformer. It is installed after the inverter and reduces the high-frequency voltage to 60-70 V. Thanks to the inclusion of a ferrite magnetic core in the design of this module, it is possible to reduce the weight and dimensions of the transformer, as well as reduce power losses and increase the efficiency of the equipment as a whole. For example, the weight of a transformer that has an iron magnetic core and is capable of providing a current of 160 A will be about 18 kg. But a transformer with a ferrite magnetic core with the same current characteristics will have a mass of about 0.3 kg.
Secondary output rectifier. It consists of a bridge that contains special diodes that respond to high-frequency current at high speed (opening, closing and recovery takes about 50 nanoseconds), which conventional diodes are not capable of. The bridge is equipped with radiators that prevent it from overheating. The rectifier also has protection against voltage surges, implemented in the form of an RC filter. At the output of the module there are two copper terminals, which ensure reliable connection of the power cable and ground cable to them.
Control board. All operations of the inverter are controlled by a microprocessor, which receives information and controls the operation of the device using various sensors located in almost all components of the unit. Thanks to microprocessor control, ideal current parameters are selected for welding various types of metals. Also electronic control allows you to save energy by supplying precisely calculated and dosed loads.
Soft start relay. To prevent the rectifier diodes from burning out from the high current of charged capacitors during startup of the inverter, a soft start relay is used.

How does an inverter work?

Below is a diagram that clearly shows the principle of operation of a welding inverter.

So, the operating principle of this welding machine module is as follows. The primary rectifier of the inverter receives voltage from the household electrical network or from generators, gasoline or diesel. The incoming current is alternating, but as it passes through the diode block, becomes permanent. The rectified current is supplied to the inverter, where it is converted back into alternating current, but with changed frequency characteristics, that is, it becomes high-frequency. Next, the high-frequency voltage is lowered by a transformer to 60-70 V with a simultaneous increase in current. At the next stage, the current again enters the rectifier, where it is converted into direct current, after which it is supplied to the output terminals of the unit. All current conversions controlled by a microprocessor control unit.

Causes of inverter failures

Modern inverters, especially those made on the basis of an IGBT module, are quite demanding in terms of operating rules. This is explained by the fact that when the unit is operating, its internal modules generate a lot of heat. Although radiators and a fan are used to remove heat from power components and electronic boards, these measures are sometimes not enough, especially in inexpensive units. Therefore, you need to strictly follow the rules that are indicated in the instructions for the device, which imply periodically turning off the unit to cool down.

This rule is usually called “On Duration” (DS), which is measured as a percentage. Without observing the PV, the main components of the device overheat and fail. If this happens to a new unit, then this breakdown is not subject to warranty repair.

Also, if the inverter welding machine is working in dusty rooms, dust settles on its radiators and interferes with normal heat transfer, which inevitably leads to overheating and breakdown of electrical components. If the presence of dust in the air cannot be eliminated, it is necessary to open the inverter housing more often and clean all components of the device from accumulated contaminants.

But most often inverters fail when they work at low temperatures. Breakdowns occur due to the appearance of condensation on the heated control board, resulting in a short circuit between the parts of this electronic module.

Repair features

A distinctive feature of inverters is the presence of an electronic control board, so only a qualified specialist can diagnose and repair faults in this unit. In addition, diode bridges, transistor units, transformers and other parts may fail electrical diagram apparatus. To carry out diagnostics yourself, you need to have certain knowledge and skills in working with measuring instruments such as an oscilloscope and a multimeter.

From the above, it becomes clear that, without the necessary skills and knowledge, it is not recommended to start repairing the device, especially electronics. Otherwise, it can be completely damaged, and repairing the welding inverter will cost half the cost of a new unit.

Main malfunctions of the unit and their diagnostics

As already mentioned, inverters fail due to the impact on the “vital” important blocks apparatus of external factors. Also, malfunctions of the welding inverter can occur due to improper operation of the equipment or errors in its settings. The most common malfunctions or interruptions in the operation of inverters are:

The device does not turn on

Very often this breakdown is caused malfunction network cable apparatus. Therefore, you first need to remove the casing from the unit and ring each cable wire with a tester. But if everything is in order with the cable, then more serious diagnostics of the inverter will be required. Perhaps the problem lies in the standby power supply of the device. The method of repairing the “duty room” using the example of a Resanta brand inverter is shown in this video.

Welding arc instability or metal spattering

This malfunction may be caused by incorrect current setting for a certain electrode diameter.

Advice! If there are no recommended current values on the packaging for the electrodes, then it can be calculated using the following formula: for each millimeter of equipment there should be a welding current in the range of 20-40 A.

It should also be taken into account welding speed. The smaller it is, the lower the current value must be set on the control panel of the unit. In addition, to ensure that the current strength corresponds to the diameter of the additive, you can use the table below.

Welding current is not adjustable

If the welding current is not regulated, the cause may be regulator failure or a violation of the contacts of the wires connected to it. It is necessary to remove the unit casing and check the reliability of the conductor connections, and, if necessary, test the regulator with a multimeter. If everything is in order with it, then this breakdown can be caused by a short circuit in the inductor or a malfunction of the secondary transformer, which will need to be checked with a multimeter. If a malfunction is detected in these modules, they must be replaced or rewound by a specialist.

High power consumption

Excessive power consumption, even if the device is without load, most often causes turn-to-turn short circuit in one of the transformers. In this case, you will not be able to repair them yourself. You need to take the transformer to a mechanic to rewind it.

The electrode sticks to the metal

This happens if the network voltage drops. To get rid of the electrode sticking to the parts being welded, you will need to correctly select and configure the welding mode (according to the instructions for the device). Also, the voltage in the network may sags if the device is connected to an extension cord with a small wire cross-section (less than 2.5 mm 2).

Often, a drop in voltage causing electrode sticking occurs when using a power extension cord that is too long. In this case, the problem is solved by connecting the inverter to the generator.

Overheat light on

If the indicator is on, this indicates overheating of the main modules of the unit. Also, the device may turn off spontaneously, which indicates when thermal protection is triggered. To prevent these interruptions in the operation of the unit from occurring in the future, you again need to adhere to correct mode ON duration (DS). For example, if duty cycle = 70%, then the device should operate in the following mode: after 7 minutes of operation, the unit will be given 3 minutes to cool down.

In fact, there can be quite a lot of different breakdowns and the reasons that cause them, and it’s difficult to list them all. Therefore, it is better to immediately understand what algorithm is used to diagnose a welding inverter in search of faults. You can find out how the device is diagnosed by watching the following tutorial.