Inverter welding does not weld, the light bulb interferes with overheating. Breakdowns and repairs of various types of Resanta welding machines. Diagnosis of faults in welding inverters
Malfunctions of welding inverters are most often caused by either illiterate or careless operation, since these are quite reliable devices and there is simply nothing to break. However, it can also be the fault of the manufacturer who installed a low-quality part or performed a poor installation.
Let's try to generalize a little typical faults welding inverters and ways to eliminate them.
1. Unstable arc combustion or strong spattering of metal during the welding process.
This may be the result of an incorrectly selected . The manufacturer indicates recommendations for selection on the pack of electrodes. If such information is not available, it is worth using simplest formula: for 1 mm of thickness of a piece electrode it is necessary to apply from 20 to 40 Amperes of current.
2. Electrode sticking even with the anti-stick function.
Most often this is caused by too low voltage in the supply network, and in the case of a welding machine with a reduced voltage - the latter drops below the minimum when the load is connected.
Another cause of sticking is poor contact in the panel sockets. To fix it, just tighten the fasteners or fix the inserts.
The voltage drop may be due to the use of a power extension cord with a wire cross-section of less than 2.5 mm, which again leads to a decrease in the effective supply voltage of the welding machine. In addition, the reason may lie in the extension wire being too long. It is worth noting that if the wire length is over 40 meters effective work impossible - too big losses.
The cause of sticking may also be burnt contacts in the connections of the supply circuit, which again leads to a significant “drain” of voltage.
3. There is no welding, although all indicators work.
The first cause of malfunction is overheating welding inverter. In the presence of warning lamp or indicator, their glow may not be noticeable if the welding inverter does not have an audible overheat signal.
A transistor in a welding inverter damaged due to overheating
Working transistor in a welding inverter
The second reason is a break in the welding cables, or spontaneous disconnection.
Third, failure of control parts. To eliminate the cause, you will have to open the case and first visually inspect the filling for damaged parts. Sometimes the reason lies in poor-quality soldering - it is enough to re-solder the parts.
4. Turn off the voltage when welding.
Most often caused by a malfunction of the switch itself or its inadequacy rated current. The switch must withstand current up to 25 A.
5. The overheat indicator lights up.
Excessive load, especially when thick layer dust inside the case. If the cooling fan malfunctions, the welding inverter usually does not turn on, although this may depend on the specific model.
Of course, it is impossible to describe in detail all the reasons and possible malfunctions welding machines. However, careful attention to the welding inverter used can prolong its “life” for a long time, and bring joy to the owner from work.
Welder running in after repair. Thermal control:
Radical repair of malfunctions of the welding inverter GYS 3200:
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 such measuring instruments, like 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” units of the device 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 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, 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, 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.
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 to repair the welding inverter, make sure that it is disconnected from the power supply.
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 faults 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 carried out visual inspection
device.
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
refers to the terminal block. The welding cable is connected to it.
There are several groups of all malfunctions of inverter welding machines:
- malfunctions that occur during wrong choice welding operating mode;
- 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 of incorrect operating mode.
Each inverter must be accompanied by instructions that list possible faults and recommendations for eliminating them.
The main types of breakdowns of welding inverters and their elimination
Basically, breakdowns of welding inverters are the result of exposure to any external factors or errors during setup and operation of the devices.
Diagram of the main elements of a welding inverter.
The most common malfunctions:
- 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.
- 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).
- 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.
- 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. The 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.
- 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.
- 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.
- 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.
- 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.
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 device, may 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 repairs may require special equipment: 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 did not lead to success, it is better to entrust the repair of the inverter apparatus to the specialists at the 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.
Each inverter must be accompanied by instructions that list possible faults and recommendations for eliminating them.
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 body of the device is opened and a visual inspection of its contents is carried out.
- 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 strength must correspond to the type and diameter of the electrode and the speed of the 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 electrical circuit can also reduce tension.
- 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.
During prolonged operation, 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 fault 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 the breakdown of the winding high voltage, short circuit between the wires or poor connection with 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.
Each inverter must be accompanied by instructions that list possible faults and recommendations for eliminating them.
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.
What is overheating of a welding inverter, how does it manifest itself, when does it happen and what to do in this case?Answer:
Overheating can happen with almost any equipment, especially where work is carried out high currents or temperatures. Therefore, overheating of a welding inverter is a common thing, quite natural, and there is no need to rush to be afraid of it. Moreover, almost all welding machines today are equipped with overheating protection, which is designed to prevent equipment breakdown due to such situations.
Overheating of the welding inverter occurs when the machine is working long time without a break. In this case, the time period for each specific model will be individual. However, for household welding inverters it ranges from thirty minutes to one and a half hours (depending on the quality of components and assembly of the device), for semi-professional models this period increases and ranges from an hour to two hours, and professional welding inverters can often work for a very long time.
It should be taken into account that the operating time interval also strongly depends on the temperature in environment. On a hot sunny day, overheating can occur much faster than during cooler hours in the off-season. By the way, each device has a built-in ventilation system, otherwise it would not be able to work for even a few minutes. But making it very large, efficient, but at the same time cumbersome is impractical. Therefore, than smaller device, the less often is his period of work without rest.
How to determine that the welding inverter is overheated? It will turn off and refuse to turn on for a while. This will mean that the protection has worked. However, we do not recommend letting things go to such a semi-emergency shutdown. Determine the approximate working time period for your tool and give the device a rest in advance so that it does not wear out too quickly.
By the way, it is believed that among household welding inverters, and have a long operating time. That is why these devices are purchased with such pleasure by summer residents, who usually use them during hot summers. vacation days. From semi-professional and professional equipment Germans have proven themselves well in this regard