Breakdowns and repairs of various types of Resanta welding machines. Recommendations for repairing inverter welding machines The overheating light on the inverter welding machine came on

It is well known that the repair of welding machines in the vast majority of cases can be organized and carried out independently. The only exception is the restoration of the electronic inverter, the complexity of the circuitry of which does not allow for a full repair at home.

Just trying to disable the inverter protection can baffle even an electrical specialist. So in this case, it is best to seek help from a specialized workshop.

The main manifestations of problems with electric arc welding machines are:

• the device does not turn on when connected to the mains and started;
• sticking of the electrode with a simultaneous hum in the area of ​​the converter;
• spontaneous shutdown of the welding machine in case of overheating.

Repairs always begin with an inspection of the welding machine and checking the supply voltage. Repairing transformer welding machines is not difficult, and they are not picky about maintenance. With inverter devices, it is more difficult to determine a breakdown, and repairs at home are often impossible.

However, if handled properly, inverters last a long time and do not break down. Must be protected from dust high humidity, frost, store in a dry place. There are the most typical malfunctions of welding machines that you can fix yourself.

The device does not start

In this case, first of all, you need to make sure that there is voltage in the network and the integrity of the fuses installed in the transformer windings. If they are in good working order, you should use a tester to ring the current windings and each of the rectifier diodes, thereby checking their performance.

If one of the current windings breaks, it will need to be rewinded, and if both are faulty, it is easier to replace the entire transformer. The damaged or “suspicious” diode is replaced with a new one. After renovation welding machine turn it on again and check for serviceability.

Sometimes the filter capacitor fails. In this case, the repair will consist of checking it and replacing it with a new part.

If all elements of the circuit are in working order, it is necessary to deal with the mains voltage, which can be greatly underestimated and is simply not enough for the normal functioning of the welding machine.

Electrode sticking (arc interruption)

The cause of electrode sticking and arc interruption may be a decrease in voltage due to short circuit in the transformer windings, faulty diodes or loose connecting contacts. A breakdown of the capacitor filter or a short circuit is also possible. individual parts on the body of the welding machine.

Organizational reasons due to which the device does not cook as it should include excessive length welding wires(more than 30 meters).

If sticking is accompanied by a strong hum from the transformer, this also indicates an overload in the load circuits of the device or a short circuit in the welding wires.

One of the repair options to eliminate these effects could be restoring the insulation of connecting cables, as well as tightening loose contacts and terminal blocks.

Spontaneous shutdown

In some cases, repairs can be carried out independently if the device begins to turn off spontaneously. Most models of welding machines are equipped protective circuit(automatic), triggered in a critical situation, accompanied by deviation from normal operation. One of the options for such protection involves blocking the operation of the device when the ventilation module is turned off.

After spontaneous shutdown of the welding machine, first of all, you should check the state of the protection and try to return this element to working condition.

If the protective unit is triggered again, it is necessary to proceed to troubleshooting using one of the methods described above related to short circuits or malfunctions of individual parts.

In this situation, first of all, you should make sure that the cooling unit of the unit is working normally and that overheating internal spaces excluded.

It also happens that the cooling unit does not cope with its functions due to the fact that the welding machine was under a load for a long time that exceeded the permissible norm. The only correct solution in this case is to let it “rest” for about 30-40 minutes, and then try to turn it on again.

In the absence of internal protection, the safety circuit breaker can be installed in electrical panel. To maintain normal functioning of the welding unit, its settings must correspond to the selected modes.

Thus, some models of such devices (welding inverter, in particular), in accordance with the instructions, must work according to a schedule that requires a break of 3-4 minutes after 7-8 minutes of continuous welding.

Malfunctions of inverter devices

Before repairing an inverter welding machine with your own hands, it is advisable to familiarize yourself with the principle of operation, as well as its electronic circuit. Knowing them will allow you to quickly identify the causes of breakdowns and try to eliminate them in a timely manner.

Electrical diagram

The operation of this device is based on the principle of double conversion of the input voltage and obtaining a constant welding current at the output by rectifying the high-frequency signal.

The use of an intermediate high-frequency signal makes it possible to obtain a compact pulse device that has the ability to effectively regulate the output current.

Failures of all welding inverters can be divided into the following types:

• malfunctions associated with errors in choosing the welding mode;
• operational failures caused by failure of the electronic (converter) module or other parts of the device.

The method for identifying inverter faults associated with disturbances in the operation of the circuit involves sequential execution of operations carried out according to the principle “from simple damage to more complex damage.” The nature and cause of breakdowns, as well as repair methods, can be found in more detail in the summary table.

It also provides data on the main welding parameters, ensuring trouble-free (without turning off the inverter) operation of the device.

Features of operation

Maintenance and repair of welding machines inverter type differs in a number of features related to the complexity of the circuitry of these electronic units. Repairing them will require certain knowledge, as well as the ability to handle such measuring instruments, How digital multimeter, oscilloscope and the like.

Under renovation electronic circuit produced first visual inspection boards in order to identify burnt or “suspicious” elements within individual functional modules.

If during the inspection no violations can be detected, the troubleshooting continues by identifying violations in the operation of the electronic circuit (checking voltage levels and the presence of a signal at its control points).

To do this, you will need an oscilloscope and a multimeter, which you should start working with only if you have complete confidence in your abilities. If you have any doubts about your qualifications, the only right decision is to take (take) the device to a specialized workshop.

Complex repair specialists pulse devices They will promptly find and eliminate the malfunction that has arisen, and at the same time carry out maintenance of this unit.

Self-repair procedure

If a decision is made to self-repair fees - we recommend using the following tips experienced specialists.

If burnt wires and parts are discovered during a visual inspection, you should replace them with new ones, and at the same time reconnect all connectors, which will eliminate the possibility of loss of contact in them.

If such repairs do not lead to the desired result, you will have to begin a block-by-block examination of the electronic signal conversion circuits.

To do this, it is necessary to find sources that provide voltage and current diagrams intended for a more complete understanding of the operation of this unit.

Focusing on these diagrams using an oscilloscope, you can sequentially check all electronic chains and identify a node in which the normal signal conversion pattern is disrupted.

One of the most complex components of an inverter welding machine is the electronic key control board, the serviceability of which can be checked using the same oscilloscope.

If you have doubts about the functionality of this board, you can try replacing it with a working one (from another, working inverter) and try to start the welding machine again.

If the outcome is favorable, all that remains is to send your board for repair or replace it with a purchased new one. The same should be done if there are suspicions about the serviceability of all other modules or blocks of the welding machine.

In conclusion, let us recall that the repair of any welding units (and inverters, in particular) is considered a rather complex procedure that requires certain skills and the ability to handle complex measuring equipment.

If you have the slightest doubt about your professionalism, you should use the help of specialists and give them the opportunity to return the faulty device to work.

An inverter welding machine, like any other equipment, can sooner or later malfunction. And if this happens, then the problem can be solved in two ways: take the device to service center, whose specialization is the repair of inverter welding machines, or try to fix the problem yourself.

Before starting repairs welding inverter make sure it is unplugged.

Once you have mastered the necessary information, you will be able to fix some problems yourself, without resorting to the help of specialists. This will, of course, save you cash. However, it can take a lot of time. Let's look at how to repair welding machines with your own hands and what malfunctions occur most often.

Features of welding inverters and their repair

Inverter welding machines make it possible to perform high-quality welding with maximum comfort, while having minimal skills in working with it.

The welding inverter is characterized by more complex, but less reliable design than welding transformers and rectifiers. An inverter, unlike its electrical predecessors, is a rather complex electronic product. If the inverter device stops working, then the first thing that needs to be tested is whether the diodes, stabilizers, transistors and other elements of the electrical circuit are working inverter welding.

To do this, you need to be able to use a voltmeter, multimeter and oscilloscope. Inverter welding has its own characteristics when carrying out repairs. For example, it often happens that it is not possible to immediately identify a non-functioning part and you have to check each element of the device circuit. Therefore, in order to carry out high-quality repairs of the inverter, it is very important to own at least basic knowledge

in electronics and skills in working with electrical circuits. If you do not have this knowledge, then it is better to have the inverter repaired by specialists. Otherwise, you will simply waste time and energy, or even make the situation worse. Each inverter must be accompanied by instructions that list possible malfunctions and recommendations for eliminating them.

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Diagnosis of faults in welding inverters

In the power supply of a welding inverter, capacitors most often fail.

Before you begin repairing inverter welding, you should know what the main types of faults are.

First, a visual inspection of the device is carried out.

If there are places with damaged contacts, the parts need to be disconnected, cleaned and reconnected. To the most vulnerable places of welding inverter device

High current and poor contact lead to heating at the junction of the wires, which can be critical for the device.

There are several groups of all malfunctions of inverter welding machines:

• malfunctions that occur when the welding operating mode is incorrectly selected;
• breakdown or improper operation of the electronic parts of inverter welding.

In both cases, welding work is either difficult or completely impossible. There are several factors that contribute to the occurrence of malfunctions.

They must be diagnosed sequentially, starting with simple operations and ending with complex ones.

When testing the control unit of a welding inverter Special attention It is necessary to pay attention to the induction coils of the voltage regulator.

The causes of electrical circuit malfunction may be:

• moisture getting inside the device (operating the device during precipitation);
• dust accumulated inside the device casing disrupts the normal cooling of electrical circuit elements (usually this occurs during constant operation on construction sites);
• overheating of the inverter as a result correct mode work.

and recommendations for eliminating them.

The main types of breakdowns of welding inverters and their elimination

Basically, breakdowns of welding inverters are a consequence of exposure to any external factors or errors during setup and operation of devices.

Diagram of the main elements of a welding inverter.

The most common malfunctions:

1. Unstable combustion welding arc or excessive spattering of electrode material. The reason is that the current does not match the type and diameter of the electrode and the welding speed. The required current strength can be found from the recommendations of the electrode manufacturer, which are indicated on the packaging. If this information is not indicated, then you can use the formula for calculating the current: 20-40 A per 1 mm of electrode diameter. When the welding speed decreases, the current must also be reduced.
2. Adhesion welding electrode to metal. This may be due to several reasons. In most cases, this happens because the device is connected to a network with insufficient supply voltage. This may also be a consequence of poor contact of the device modules in the panel sockets. This problem can be eliminated by tightening the fasteners and securing the boards well. The voltage at the inverter input may drop when using a power extension cord whose wire cross-section is less than 2.5 mm 2. An excessively long extension cord can also cause a voltage drop (with a wire length of 40 m or more, operation of the device is practically impossible, since large current losses occur in the circuit). The electrode may stick due to oxidation or burning of contacts in the circuit, which can also lead to a voltage drop. This problem can also be encountered if the materials to be welded are not properly prepared (the contact between the electrode and the part deteriorates if there is an oxide film on it).
3. No welding when the inverter is turned on and the indicators are working. The reasons for this in most cases are overheating of the device and spontaneous disconnection or damage to the welding cables.
4. Spontaneous shutdown of the inverter. When the transformer is connected to the network, its protection is triggered and the device turns off. The cause may be a short in the circuit between the wires and the housing. Protection can be activated when there is a short circuit between sheets of magnetic wire or turns of coils and breakdown of capacitors. Remedy: disconnect the transformer from the network, find faulty element and repair it - replace the capacitor, restore the insulation, etc.
5. High current consumption with little or no network load. Possible reason- short circuit of the turns on the coils. The problem is resolved by rewinding or adjusting the insulation layer.
6. The reason for shutdown is welding work mains voltage may become incorrectly selected circuit breaker. It should be designed for a current of up to 25 A.
7. Stopping the inverter during long-term welding. Most likely the cause of this is overheating. If exceeded permissible temperature protection is triggered. Wait 20-30 minutes and continue working.
8. The transformer may make a loud noise, which is accompanied by overheating of the device. One of the reasons is the weakening of the bolts that tighten the sheet elements of the magnetic wire. The reason for this may be a malfunction in the core fastener, an overload of the transformer, or a short circuit between the welding cables. Check and tighten all bolts, eliminate the fault in the core fastening, restore the insulation of the welding cables.

Here we will consider the repair of the TELWIN Force 165 welding inverter. For those who are not familiar with the design and circuitry of the welding inverter, we suggest that you first familiarize yourself with the materials on this topic, namely:

In these two articles, using the example of a real TELWIN Force 165 machine and a circuit diagram of TELWIN Tecnica 144-164 welding inverters, the electronic filling and purpose of each circuit element are described in detail.

But let's return to our faulty device - the TELWIN Force 165 welding inverter. According to the owner, the device was working properly, but suddenly, after a short break in work, it completely refused to perform its duties. When trying to start work, a spark did not appear, and an unnatural sound was heard from inside the case. regular work"hum" and "squeak".

According to the owner, it was also known that the device seemed to be working - the noise of the blower fan was heard, and the normal operation indicator turned on. This indicates that the inverter transistors are working properly.

One got the impression that the welding inverter “goes into protection” - the internal protective circuits that are part of any pulsed unit, especially such a powerful one, are triggered.

I started troubleshooting the welding inverter in an unconventional way. I did not turn on the device.

I had never encountered such devices before, and they were new to me. Therefore, the first thing I did was open the case and began to check all the details hitherto known to me with a multimeter.

On printed circuit board welding inverter found familiar elements: a fan, a powerful diode bridge (a radiator is installed on it), high-voltage electrolytic filter capacitors, an EMC filter, key powerful inverter transistors (installed on a radiator), a pulse transformer, an electromagnetic relay ...

An unpleasant surprise was that the surface of the printed circuit board was filled with some kind of varnish, which made it difficult to read the markings of SMD elements and microcircuits.

Security elements were also discovered. One of them is a 90 0 C thermal fuse. It is glued to the radiator of the diode bridge.

As far as I know, such thermal fuses operate permanently, that is, if they heat up above their operating temperature, they open forever. Similar thermal fuses can be found in power transformers. There they are included in the circuit of the primary winding and glued to it. Protect the transformer from overheating. Sometimes you can falsely judge that the primary winding of the transformer is broken, although as soon as you remove (or short-circuit) this same thermal fuse, it turns out that the transformer is working.

Therefore, the first thing I did was check the integrity of the thermal fuse at 90 0 C. It turned out to be working.

In addition, on one of the radiators, to which the powerful key transistors of the inverter are attached, there is also temperature sensor. Externally, it is very similar to the KSD series thermal switch, which are used in thermopots, water heaters and other household electrical equipment.

The peculiarity of these thermal switches is that their contacts close again if the temperature drops below a certain value. It is clear that this temperature sensor monitors the heating of powerful key transistors and, if there is overheating, temporarily turns off the operation of the welding inverter. As soon as the radiators, and, consequently, the transistors, cool down, the device will start up again and operate in normal mode.

When checking the thermal switch, it turned out that it was also working. Well, let's look for the problem further.

After some searching, it was decided to test powerful rectifier diodes. On the printed circuit board they are arranged in a row and securely screwed to the radiator with screws. The pages of the site have already talked about how to check the diode.

Labeled as 60CPH03. These are ultra-fast dual diodes VS-60CPH03.

After checking, it turned out that all three dual diodes were approximately faulty. But this is just an assumption, since the diodes are soldered into the circuit, and it is impossible to say 100% that they are faulty. Despite this, it became clear in which direction we needed to “dig” further.

It would have been possible to understand the problem without the diagram, but with it it was more interesting, especially since I had at hand a repair manual for TELWIN Tecnica 144-164 welding inverters, which, frankly speaking, are not much different in their composition and circuitry from the TELWIN Force 165. If you look at schematic diagram, then you can notice that even if one of the dual 60CPH03 diodes breaks down, all other diodes during testing will also be “faulty” unless they are removed from the board and each one is checked separately. Here is a piece of the circuit - the output rectifier.

As it turned out, desoldering these same diodes is not so easy. Firstly, the soldering is very decent and high quality. And how could it be different, because huge currents flow in the power part of the welding machine, up to 130 amperes! The slightest lack of solder and the contact point will heat up, and this will subsequently lead to a malfunction. Therefore, the Italians do not spare solder and reliably flavor the contact area with it.

Don't forget that modern electronics are made using lead-free solders, and their melting point is usually higher than that of conventional tin-lead.

Before soldering the diodes, it is necessary to dismantle the radiator. The screws that secure the diodes to the radiator are non-standard, but you can unscrew them with pliers.

For desoldering, it is better to use a more powerful soldering iron. It is better to take a regular soldering iron with a power of 50 watts, otherwise desoldering will turn into torture. You can, of course, use a 40-watt soldering iron, but this will require skill and a lot of patience. You need to have time to thoroughly warm up all 3 leads of the diode at the same time.

When dismantling, you can try using copper braid or a desolder to remove solder. True, if the soldering iron is low-power (for example, 40 watts), then they will be of little use. The solder will harden instantly.

Despite the difficulties caused by the low power of the soldering iron (I have a 40-watt one) and the burnt copper tip, I still managed to desolder the dual diodes. Unfortunately, not without its “jambs”.

I tore out by the roots the through metallization of the copper tracks. Oh, okay, no problem. Let's clean it up and build it up.

It turned out that one of the diodes was broken - the rest were intact. It is worth noting that both diodes, which are part of one dual diode, turned out to be broken. Now this is not a diode - but a “sieve” - an ordinary conductor in a beautiful case.

If you look at the diagram, the diode indicated by the red circle has “flyed out”.

Let me remind you that a piece of the circuit is taken from the manual for TELWIN Tecnica 144-164. And I was repairing TELWIN Force 165. Telvin Force 165 does not have an L1 inductor on the board (inductor) and, apparently, should not have it, since seat there is no one for it on the board. So don't pay any attention to her. In reality, this coil is made of copper wire large cross-section to withstand currents up to 140 amperes.

It was decided to leave the device alone and start looking for a replacement for the faulty VS-60CPH03 diode. Finding a replacement for the 60CPH03 diode was not so easy. It was not possible to buy this radio component on the Internet. For some reason, such a detail is rare in online stores (perhaps everything has already changed). I had to go to the radio market and buy there.

An analog diode with markings was purchased STTH6003CW. His price turned out to be decent, and finding the right one was not easy.

The parameters of the STTH6003CW are the same as those of the VS-60CPH03, namely:

Frame - TO-247;

Maximum current in direct connection I F(AV)– 30A for 1 element (60A for both diodes);

Allowable reverse voltage V RRM– 300V;

Recovery time (or speed) t rr (max)– 50 ns (50 nanoseconds).

The STTH6003CW dual diode belongs to the so-called high-speed diodes. The bourgeoisie call such diodes names Ultra-fast, Hyperfast, Super-fast, Stealth diode, High frequency secondary rectifier and so on. In general, as soon as they don’t try to emphasize their coolness.

The main feature of a high-speed diode is its ability to open quickly (pass current) and also close quickly (not pass current). This means that it can operate at high frequencies. This is what is required for operation in the rectifier of a welding inverter, since it is necessary to rectify high frequency current - tens of kilohertz.

Therefore, such diodes should only be replaced with high-speed ones!

To replace the diode VS-60CPH03 will fit STTH6003CW, FFH30US30DN. All these diodes are analogues and are excellent for replacing each other. They are actively used in welding machines. Also suitable STTH6003 TV , but he has a different body ( ISOTOP), although if there is no other, then, if desired, you can contrive and screw it somewhere.

When installing diodes on a radiator, it is necessary to use thermal conductive paste (for example, KPT-8).

You shouldn’t be greedy, but you shouldn’t overly spread the paste on the area of ​​thermal contact. Apply a small, even layer of paste to the contact area of ​​the diode body and aluminum radiator. Then securely screw the diode housing to the radiator with a screw.

Installing diodes on a radiator should be taken seriously. During operation, the diodes get very hot and the slightest difficulty with cooling will cause them to overheat and fail.

When installing diodes, it is necessary to solder the connection points of the leads and contacts of the copper tracks as best as possible. This is very important, since the currents are simply huge and if you cheat, nothing good will come of it.

If during dismantling the copper coins and copper tracks were “torn off”, then they can be built up with tinned copper wire and soldered with high quality. Purely electrical contact not enough - soldering must be reliable.

After replacing the faulty diode, the device started working.

An archive with diagrams for welding machines TELWIN Tecnica 141-161, TELWIN Tecnica 144-164 and TELWIN Tecnica 150, 152, 170, 168GE can be downloaded. File size - 4.4 Mb.

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 use 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.

Welding inverters, depending on the model, work like household ones electrical network(220 V) and 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.

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 microprocessor unit management.

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 electronic board control, therefore only a qualified specialist can diagnose and fix a malfunction 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 of external factors on the “vital” units of the device. 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 incorrect setting current strength 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 not regulated welding current, the reason 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, it is again necessary to adhere to the correct duty cycle (ST). 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, various breakdowns and there can be quite a lot of reasons that cause them, and it is 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.

Welding inverter is modern equipment, the use of which in the welding process makes it possible to achieve very High Quality work and provides the welder with the opportunity to work in comfortable conditions. But at the same time, the welding inverter also has a more complex design, compared to previous models of welding equipment, which increases the chance of a malfunction occurring during its operation.

As a rule, all malfunctions of the welding inverter can be divided into two groups:

• malfunctions associated with improper operation of the electronic “stuffing” of the device

• malfunctions associated with wrong choice operating mode.

The second type of malfunction occurs most often, therefore, before contacting a specialized workshop or starting to disassemble the device yourself in order to identify a breakdown, you need to check whether all operating mode settings are set correctly, and in addition, you should read the operating instructions for this device again, to determine if you are making any mistakes while working. Most manufacturers, when drawing up instructions, indicate the causes of welding inverter malfunctions that may occur during operation, and also describe how these malfunctions can be eliminated independently.

Causes of breakdowns of welding inverters and options for eliminating them.

There are a number typical faults, which arise when we're talking about about welding inverters:

• instability of the welding arc and strong spattering of metal;
• welding electrode sticking;
• lack of welding process when the machine is turned on;
• lack of response from the device when it is turned on.

Let us consider in more detail why this or that situation may arise, and what can be done in the event of any malfunction of welding inverters.

• Instability of the welding arc and strong spattering of metal.

This malfunction can occur if you select the wrong current when welding. As a rule, the welding current is selected in accordance with the type and size of the electrode used for welding. But here it is necessary to remember one more thing important rule: the selected current must correspond to the speed at which welding is carried out. If the welding speed decreases during operation, then the welding current must be reduced.

• Welding electrode sticking.

In fact, there may be several reasons for this type of malfunction. It is quite possible that during welding the voltage in the network suddenly decreased, which led to severe sticking of the welding electrode. It can also “stick” if the inverter is connected to the network with a cable with too small a cross-section. Another reason for this “behavior” of the electrode may be poor contact of the electrode with the surface to be welded due to the fact that the surface has undergone oxidation due to exposure to atmospheric oxygen. In this case, welding must be stopped and the surface of the part must be cleaned of film.

• Lack of welding process when the machine is turned on.

In the vast majority of cases, this behavior of the welding inverter can be explained by the lack of mass on the surface of the part being welded. In addition, it would be useful to check the condition of the welding cable - it may be damaged. This situation occurs quite often if the part being welded is heavy, as a result of which the part falling onto the wire can damage its integrity.

• The device does not respond when turned on.

If nothing happens when you turn on the welding inverter, then the cause of such a malfunction should be sought, in many cases, not in the inverter itself, but in the electrical network to which it is connected. It is possible that the mains voltage is too low and therefore the device cannot operate. Another reason that the device does not turn on may be an incorrectly selected circuit breaker installed in the panel. A weak switch can turn off when the inverter is turned on. In addition, turning off the device can lead to a loss of electricity throughout the house.

In addition to the indicated malfunctions, there are also interruptions in the operation of the welding inverter, which are not related to the breakdown of the device, but are a consequence of the fairly high-quality and timely operation of the protection systems with which the inverter is equipped. So, for example, with long-term continuous operation The inverter may turn off spontaneously. This happens if the device overheats and the temperature protection trips. In this case, you should stop the welding process for about 20-30 minutes, allow the device to cool, after which work can be continued.