How to connect welding correctly

How to connect the welding machine to the network?

Reading time: ≈5 minutes

So, you have purchased your first inverter welding machine. You will probably find an instruction manual included with it. Having carefully studied it, you will find that only a few general phrases are said about the correct inclusion. Is it really that simple? Plug the plug into the outlet and that's it? Alas, no.

An inverter-type welding machine is a complex device with its own nuances and features. By thoughtlessly plugging it into a household outlet, you risk losing the device itself or the wiring in the house. So how to connect a welding inverter correctly?

In this article we will briefly describe how to connect a welding machine to a 220 Volt home network and what should be taken into account.


Before you learn how to properly wire a welder, you need to make sure that the wiring in your home can handle the welding job.

Inspect the sockets, how old are they? If the outlets have not been replaced for more than 25 years, most likely all the wiring in the house is also old. This is not critical if it can withstand high current values. But often old wiring brings nothing but problems.

You are unlikely to be able to use modern welding wires with the machine if the power supply in the house is far from ideal.

You don't need to be an electrician to understand what will happen if you connect a powerful modern welder to old sockets. At best, you will be left without electricity. In the worst case, all your neighbors will be left without electricity, and your electrical appliances will simply fail.

In a word, check first whether your wiring can withstand the load. If you find that it can't, don't despair. This problem can be solved. We'll talk about this later. In the meantime, below is a diagram of connecting the welding machine.

Application of a current generator

So, you checked your wiring and it turned out that connecting a 220V welding machine is simply impossible. What to do in this situation? You can use a third-party current generator.

And at this moment, many immediately begin to remember that they keep an old gasoline generator in their dacha, which more than once saved them from sudden power outages. On the surface, the use of such generators seems like a pretty good idea, but in practice everything is different. Often, all gasoline generators are low-power and are not capable of providing a voltage of more than 5 kW for a long time.

As you understand, connecting a welding inverter to a low-power gas generator is simply pointless. To find out how much power you need, simply multiply the amperage you'll be cooking with by the voltage.

Let's take the most popular situation: you are welding with a 3 mm electrode with a current of 120 Amps and a voltage of about 40V. We multiply 120 by 40, we get 4.8 kW. This is the minimum power that a gas generator must provide. But in the calculations we did not take into account the efficiency of the welding machine, which is less than 100%. To ensure uninterrupted operation of the inverter you need at least 6 kW.

In general, a gas generator is a choice for those who no longer have any opportunity to obtain an additional power source. Ideally, before purchasing an inverter, you should check all the wiring and, if it is unsuitable, buy a welder with a built-in generator. Yes, these models are expensive and very bulky. But this is the most convenient solution to the problem.

If this solution is inconvenient for you, then you can buy a special current stabilizer for the welding machine. It connects directly to the welding inverter. This solution is suitable for a more or less stable power grid.

Use of extension cords

The topic of extension cords does not relate to connecting a welding machine, but these two issues are related. The fact is that if you select the wrong extension cables, the voltage may drop and the efficiency of the welding machine may decrease.

Why are extension cords needed? After all, the kit already contains quite long wires, usually up to 2.5 meters. At first this may be enough, but over time you will want more freedom for your actions. Especially if the device is heavy, and you need to move around the entire summer cottage or cook at height.

Therefore, we decided at the same time to tell you about connecting extension cables. First of all, remember that they cannot be used thoughtlessly. You need to accurately calculate what cross-section the extension wire should have. The maximum power that the wire can withstand will depend on this.

Let's give a simple example, using the same numbers from the previous example. Let's say we need a welding current of 120A. Wire cross-section 2.5 sq. mm. gives us 16A. Accordingly, for welding with a current of 120A, we need a wire with a cross-section of at least 12 sq. mm. We recommend choosing extension wires with a spare cross-section. Also remember to untangle them before welding so that it cools better. And don't forget about grounding. This is the simplest safety rule.

Also, do not buy several short extension cords and connect them together. It’s better to decide in advance on the required length and buy one wire. This way you will reduce the likelihood of a decrease in the efficiency of the welding machine. In addition, the contact connections of the extension cord will last you much longer.

Instead of a conclusion

Connecting the inverter to the grid is a simple process. You just need to learn everything once and then follow the rules. In addition, these rules also apply when you need to connect a 380V welding machine. If you have a transformer or semi-automatic in your arsenal, the algorithm of actions will not change either. We wish you good luck in your work!


Connecting a welding inverter


Each welding machine is equipped with a standard set of cables. Without them it is simply impossible to carry out any work. Therefore, the correct connection of the welding inverter is of great importance.

All such devices are equipped not only with two working cables, but also with another one through which power is supplied. Some difficulties may arise with the cables for connecting the electrode and the clamp that provides connection to ground. There are separate connectors with plus and minus for them.

Connection options may vary depending on the material used and the work conditions.

Preparation for work and connection

Once protective clothing, shoes, a welding mask and electrodes have been prepared, you can proceed to connecting the device. Due to the increased power of the equipment, it is necessary to become familiar with the characteristics and capabilities of the network used as a power source. As a rule, there are no special problems, since all household inverters are designed for 220 volts.

The only requirement related to safety is the installation of a machine with the necessary parameters. This will avoid negative consequences in the event of short circuits and other unforeseen situations.

Next, the welding inverter is placed at the workplace in compliance with certain rules and technical standards:

  • The minimum distance from walls and large objects is 2 meters.
  • Protective grounding is mandatory.
  • There should be no flammable or explosive objects or substances nearby.
  • For welding work, you should use a metal table or just a free platform.

Having prepared the workplace, you can connect the welding inverter. Each cable and wire is inserted into the desired inverter socket. An electrode is fixed in the holder, and a ground clamp is connected to the metal workpiece. Not only a household network of 220 V can be used as a current source, but also an industrial network of 380 V. In the absence of stationary networks, the use of a gasoline or diesel generator is allowed.

Electrical connection

When connecting a welding inverter to a home network, technical problems often arise. Therefore, this procedure must be performed correctly and extremely carefully, taking into account the peculiarities of local electrical wiring. The possible uninterrupted operation of the device should also be taken into account, with precise time intervals allocated for welding and technical breaks.

First of all, it is necessary to study the characteristics and type of outlet where the inverter is connected. Typically, when operating at maximum current, the inverter is capable of outputting 140 A. With such indicators, a 16 A socket is quite sufficient. Older houses still have 10-amp products and associated wiring, which may not withstand increased loads. You should check the presence and condition of safety plugs and automatic devices.

If so-called bugs are installed as protection, then as the load increases, their presence can cause serious consequences - short circuit, melted wiring, fire, etc. It may be necessary to install a new circuit breaker, taking into account the load that the converter adds.

In some cases, a so-called network sag may occur, when the voltage drops to 150 V or lower. This is the first sign of insufficient cross-section of network wires. If the voltage drops below the minimum permissible limit, then welding equipment cannot be connected to such a network.

When using an extension cord, the coiled wire must be unwinded to its full length. Otherwise, inductive resistance may occur in places where the twists are twisted, which, in turn, will lead to overheating of the insulation, even to the point of melting.

If winding cannot be avoided, it should not be too tight to ensure natural ventilation.

Power supply for inverter welding from a generator

If the facility is not equipped with a stationary electrical network, but welding is still required, you can use a gasoline or diesel generator. The most important thing is to correctly calculate the load so that both devices are optimally combined with each other.

It must be taken into account that any inverter contains coils, capacitors, electronic circuits and other elements that are considered reactive consumers with a power factor of about 0.7. When calculating the total power of the device, it is necessary to divide the active power by the power factor.

After preliminary calculations, hardware compatibility will look like this:

  • With a welding current of 160 A, you can only work with electrodes with a largest diameter of 4 mm. The active power of such an inverter is 3.8 kW, and the total, taking into account the coefficient of 0.7, will be approximately 5-5.5 kW. Taking into account the 20% power reserve, a generator of at least 6 kW will be required.
  • Welding current of 180 A allows work with 5 mm electrodes. Active and apparent power will be 4.8 and 7.5 kW, respectively. Therefore, the generator power should be no lower than 8-8.5 kW.
  • If the welding current reaches 200 A, then such equipment needs a three-phase network. The diameter of the electrode increases to 6 mm. The total power of the inverter will be 11.5 kW, and the power of the three-phase generator will be no less than 15 kW.

Sometimes the question arises about the possibility of using a powerful welding device not to its full potential. Can a circuit for connecting an inverter to a generator with a lower power be used? Experts do not recommend making such a decision on your own; only a professional electromechanic can give a final conclusion.

It is also necessary to take into account the presence of additional options in specific equipment that require a short-term increase in power at the time of their use.

Selecting extension cord parameters

Often the power cable included with the inverter is too short and does not provide a welding connection so that it is located near the structures being connected. Therefore, welders are forced to use extension cables or carriers. They differ from similar household devices only in the increased power of the conductors.

From a technical point of view, an extension cord is nothing more than an additional section of the circuit from the inverter apparatus to the current source. Therefore, the well-known Ohm's law is quite suitable for calculations. With the same power of different connected consumers, the cross-section of the conductor directly depends on the length of the portable cable. The material should be metals with minimal resistivity.

Therefore, all modern conductors are made of copper. The insulation does not affect the electrical properties of the cable in any way, but during operation it is subjected to various mechanical loads. Its thickness should be as high as possible, in this case the cable will last much longer.

The choice of cross-section is made depending on the value of the welding current. The cable length and voltage are taken as the initial data for calculations. You should take into account the possible voltage drop in this area, which can cause overloads in the home network. It is mandatory to create a power reserve of at least 10%, eliminating the possibility of overheating of the conductors.

It is recommended to create extension cords of different lengths, divisible by 10 m, in the kit for the welding machine. It is better not to use short carrying cables. With optimal carrying sizes, it does not have a noticeable effect on the general condition of the circuit and the magnitude of its voltage. The cross-section of the cable used in the extension cord and the cross-section of the home wiring should be approximately the same. The use of household carriers to connect welding equipment is strictly prohibited.

How to connect an inverter in different polarity modes

Power cables have special terminals, designated plus and minus. Many novice users do not think about how to connect a welding inverter and connect the wires without taking into account the polarity and actual operating conditions.

Meanwhile, the difference is still present and it depends on the laws of physics, in accordance with which the movement of electrons occurs.

Having a negative charge, they move from minus to plus under any conditions, including when an inverter is included in this chain. The welding machine will work regardless of the terminal to which the electrode is connected.

However, the movement of electrons in each case will occur in different directions, and this will directly affect the workflow itself and the final result.

The direct polarity scheme involves connecting the plus to the workpiece (ground), and the minus to the electrode. An arc is formed between them, through which the welding current passes. With this connection, the anode is the part, and the cathode is the electrode. The weld seam will heat up more, about 700-1000 degrees more than the electrode.

With reverse polarity, on the contrary, the electrodes are connected to the positive terminal, and the part being welded is connected to the negative terminal. In this case, the electrode will heat up more.

The main factor in choosing polarity is the thickness of the workpieces being joined. A more massive metal requires stronger heating at the junction for better mutual penetration of molten particles. Thin materials, on the contrary, cannot be heated too much to avoid burn-through and an uneven weld.


How to connect a welding machine

Before welding, at a minimum, you need to understand how the welding machine is connected to the existing network, as well as what conditions must be observed.

To quickly and efficiently connect the welding machine, you should follow the current operating instructions for devices of this class.

Of greatest interest from the point of view of the features of this process is the connection of a welding inverter, most often used at home.

Safety regulations

The connection diagram for an inverter welding machine is quite simple and allows the device to operate in a cyclic (intermittent) mode, which allows for maximum welding efficiency. Before plugging into a socket, you still need to read the connection instructions, check the network parameters, completeness of the equipment and the external integrity of all its parts .

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Options for connecting the inverter to the network

The instructions should clearly describe how to properly connect the welding machine, and also stipulate the procedure for its safe connection to the current electrical network. The need to check plugs and circuit breakers installed in the power supply circuit is specifically stated.

The fact that in old houses aluminum wiring does not allow working with currents above 10 Amperes should also be taken into account. Therefore, before connecting converters to the network, it is necessary to find out their rated power and current consumption.

When assessing the power taken from the network, one should not forget that when the device is turned on, there is a sharp surge in the starting current, the value of which can exceed the rated value several times.

Before connecting the device and welding work, the operator must fulfill the following requirements of the operating instructions:

  1. remove foreign electrical devices (computers, transmitters, measuring instruments) from the device body;
  2. when working with inverter equipment, the workplace must be cleared of all other interfering objects;
  3. The rooms in which the welding unit is located must be equipped with a forced ventilation system.

To avoid emergency situations, before connecting the welding machine for the first time, it is recommended to test it in various welding modes.

Turning on the device (operating instructions)

When considering the operating conditions of a welding inverter, first of all, you need to pay attention to the following points:

  • the normal duration of the current load should not exceed 5 minutes;
  • in practice, the so-called “three-minute cycle” is usually used, which is two-thirds of the full load;
  • If strong heating of the case is detected, the device must be turned off until the causes of the overload are determined.

Welding using an inverter machine requires careful preparation, since dangerous situations are possible when working with equipment of this class. Before starting welding work, the operator must fulfill all the requirements of the operating instructions, including choosing the appropriate current mode and electrode type .

Connecting the inverter to the network and putting it into operation is allowed only after meeting safety conditions, including the use of sockets and plugs of the appropriate standard.

When operating a welding machine, you should use special coated electrodes (MMA type).

The thickness of MMA electrodes is selected based on the mode and type of metal to be worked with. Typically, the thicker the metal, the greater the current required and, accordingly, the diameter. The most common ones used at home are 2 and 3 mm electrodes.

Before starting welding, make sure that the electrodes are dry. The wire going to the torch is connected to the minus terminal, after which the gas hose is connected to the reducer located on the cylinder if welding is performed in a protective environment.

When connecting via an extension cord, you need to pay attention to the cross-sectional diameter of its cable. The cross-section must be at least 1.5 square meters. mm for working with current up to 16 A. The wire must be completely untwisted so that there is no inductance, which, after connecting the welding machine, will create additional resistance.

Launch Mode Features

The inverter is put into operation by pressing the “Start” button, which leads to a state of complete readiness for welding procedures. To start welding in a protective gas environment after connection, just slightly unscrew the torch valve, install the desired electrode and “strike” it on the workpiece to be welded.

When considering starting an inverter, the following must also be considered. The fact is that any inverter device is equipped with a soft start device that prevents the failure of the electronic elements of the circuit from a surge of current.

Despite such protection, current surges when turned on can reach values ​​of the order of 40 Amperes, which are dangerous not only for the outlet, but also for the existing electrical network due to the strong “sag” of voltage.

During current surges within the above limits, the mains voltage may decrease (“sag”) from 220 to 130-140 Volts.

It is recommended to connect the power supply circuit of the device to the terminal contacts located directly on the distribution panel, where the grounding bus is also supplied separately. For a machine installed in an input device, such voltage drops are less dangerous.

The situation with inrush currents is significantly simplified when linear rather than phase voltages are used to power the inverter. However, this option can be implemented only for devices designed for 380 Volts and provided that the house is connected to a three-phase network (generator).

When considering the features of putting an inverter device into operation, one should not forget the features of adjusting its load current, which is carried out automatically (using a special control unit). Setting elements that set the control limits are located on the front panel of the device.

Compliance with the instructions for connecting pulse converters is mandatory for all models of welding devices without exception. Only if the starting conditions for inverters are met is it possible to maintain their functionality and guarantee high efficiency of the welding process.


How is the welding machine connected?

In order for welding work to proceed without unnecessary problems, you need to figure out how to connect the welding machine. Before connecting the unit for welding, it must be placed in a suitable location.

It is very important that nothing obstructs the air flow to the openings on the equipment body. Cooling is often intentionally increased. To do this, when connecting the welding machine, install a fan behind it.

It is very important to ensure that the unit does not come into contact with dust, as well as wet and aggressive vapors.

Homemade welding machine for DC welding.

Basic recommendations and safety precautions

Before you are going to connect the welding machine, be sure to make sure that the frequency and voltage indicated on the equipment case match that of the network. Connecting such equipment requires making the correct connections. For this, the following wires are used: a phase or 2 phases in combination with a neutral and a grounding wire, which is usually green or yellow.

Electrode position during welding.

If the welding machine model you have chosen allows you to set the voltage yourself, you should fix the switch in a position that would correspond to the voltage in your network. The position is fixed using a locking screw.

A plug is used to connect the welding machine. It is very important that it meets established thermal throughput standards. This plug must have a grounding lug. It is to this that the corresponding cable will be connected. This plug cannot be plugged into a regular household outlet. A fused socket is suitable for connection. An auto switch is also suitable.

You will need to connect the return ground cable to the appropriate terminal. You need to connect at the shortest possible distance from the future seam. A specially designed clamp is used to attach the cable holder to the protruding fragment of the electrode.

Before connecting the welding unit directly to the network, be sure to check how securely the plugs are secured.

Due to poor contact, the device will not work at full capacity and will quickly fail.

Figure 1. Connection diagram of the welding machine: 1-welding station; 2—three-core hose cable; 3 - transformer; 4-regulator; 5-grounding clamps of the unit body; 6 - single-core hose cable; 7-electric holder; 8 - ground wires.

There are quite a lot of schemes according to which the welding unit is connected. The most common connection diagram is shown in Fig. 1.

  • Position 1 is a welding station;
  • number 2 indicates a three-core hose cable;
  • 3 - transformer;
  • 4th position - regulator;
  • number 5 - grounding clamps of the unit body;
  • 6 - single-core hose cable;
  • 7th position - electric holder;
  • number 8 - ground wires.

Remember and follow all these rules when connecting the welding machine to avoid injuries and other unpleasant consequences. Failure to comply with the safety system of the welding machine may result in fire or electric shock.

If any of the power cables break, they must be replaced immediately. It is best to entrust this work to professionals.

Any repair and maintenance work can be performed only after the welding machine is disconnected from the network.

When connecting the welding machine, be sure to check the quality of the permanently laid and flexible wires. Check their grounding, continuity and insulation to ensure compliance with established standards. Don't skimp too much on grounding.

It is best to use flexible copper wire for it. If twists, cracks or other defects are detected, the wire must be replaced. The use of damaged wires leads to overheating and may cause damage to the welding machine. An important fact is the need to unwind the wires.

If this requirement is neglected, inductance will occur and resistance will decrease.

The voltage for welding machines is not standardized, so pay attention to the characteristics of the particular model you will be working with. When assembling such equipment, it is given a certain voltage level. The resistance value is not taken into account.

Step-by-step instructions for connecting a welding machine

Figure 2. Sequence diagram for connecting the welding machine.

After you have checked the integrity of the unit and all related components, and also established the voltage compliance, you can proceed directly to connecting your welding machine. For this you will need:

  • the unit itself;
  • extension;
  • adapter for extension cord.

When connecting the device, you can refer to the diagram in Fig. 2.

The connection is made in a certain sequence, namely:

  1. First, a plug is prepared with the appropriate thermal throughput parameters.
  2. Select a socket with a circuit breaker or fuse.
  3. The return cable is connected to the terminal.
  4. The holder cable is connected to the electrode fragment using a clamp.

After you have done all this, the welding machine can be connected to the network. Most models have fairly short wires, so connecting them often requires the use of an extension cord. The extension cord must have a wire of sufficient cross-section. The reliability and safety of operation depends on the number of intermediate connections. The fewer there are, the better.

Connection features depending on the type of device

Figure 3. A transformer-type welding machine can operate in a wide range of welding current. It is recommended to connect it to the shield.

The procedure for connecting the welding machine largely depends on the features of its device. So, if a two-phase model is used, the wires will be connected in an individual sequence.

The first wire will need to be connected to the phase, the second to the neutral output, and the third wire to be connected to the protection. If you work with a three-phase welding machine, then you don’t have to follow a special sequence.

The main thing is that the first 2 wires are connected to any phases, and the third wire is connected to the protection.

It is very important to know the basic features of connecting a transformer-type device. A typical representative is shown in Fig. 3. If such equipment is used, the connection is made in accordance with a number of special rules.

Transformers can operate over a wide range of welding currents. When some of them are plugged into an outlet, a fairly powerful surge of current is generated, which can burn the outlet and turn off the circuit breaker. Therefore, it is recommended to connect such a welding machine to the shield.

A detailed connection diagram for the welding transformer is shown in Fig. 4.

Be sure to follow these rules while working. If they are not followed, you risk injury that could easily be avoided. As a result of incorrect connection of the welding machine, you may receive an electric shock, a decrease in the quality of welding, fire, etc.

Possible problems after connection

Figure 4. Connection diagram for welding transformer.

After connecting the welding machine, various problems may arise, for which you need to be prepared and know how to get rid of them. If there is strong heating of the windings and humming, then the reason lies in a turn short circuit in the primary windings. In this case, you will have to completely or partially rewind the windings.

Welding transformers may produce too much current due to a short circuit in the regulator winding or in the secondary winding. To eliminate the malfunction, you need to eliminate the short circuit in the windings or rewind.

If, when exposed to the regulator, the welding current does not decrease, then the reason, as a rule, is a short circuit between the terminals of the regulator.

While working with the device, you may hear an uncharacteristic hum. It usually appears due to weakening of the spring tension or due to a broken wire.

The cause of excessively hot contacts in connections is usually faulty electrical contact. You can get rid of this malfunction by rebuilding overheating connections. The contact surfaces are cleaned and fit tightly. The clamps are tightened until they fail. Good luck!


How to connect welding correctly

In a private home and country house there is always a need to cook something. In order not to contact professionals for small details (and not to pay them), you can buy an inexpensive welding machine and learn it yourself.

To acquire these skills, it is recommended to purchase DC welding machines, and in particular, welding inverters. They have small dimensions, weigh little, and with their help you can get a high-quality seam even without much experience.

What is equally important, in this category there are good devices at a low price (5-10 thousand rubles). Therefore, welding with an inverter for beginners is the best that the market can offer today.

What is a welding inverter and how does it work

This device was called an inverter because it converts alternating current of a 220 V network with a frequency of 50 Hz into high-frequency oscillations, and then into direct current. At the same time, the device has a high efficiency: about 85-90%, and even under fairly heavy loads the counter “winds” a little. In any case, you won’t have to pay crazy bills. The consumption will be slightly higher than without welding, but not by much.

This small box is an inverter welding machine

Most inverter welding machines operate from a 220 V household network (there are also devices from 380 V). And this is one of their advantages. Moreover, they have practically no effect on it, i.e. do not reduce tension. Rest assured about your neighbors: they won’t even know that you are welding.

The second important advantage is that they can work more or less normally at reduced voltage. Of course, you need to look at the specifications, but at 170 V, most of them still allow you to work with a 3 mm electrode.

This is very important especially for rural areas, where low voltage is the norm rather than the exception.

What’s also good for beginners is that it’s easier to get and hold an arc when using inverter welding. And in general, according to many, it cooks “softer” and has a “lighter” arc. So if you want to learn how to cook, try inverter welding first.

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Inverter Welding Basics

First, let's look at the design of the welding inverter. We won’t look at the “stuffing”; we’ll look at what’s on top and what we’ll have to use.

What does an inverter welding machine consist of? (To enlarge the picture size, right-click on it)

This device is a small metal box, which, depending on the power, weighs from 3 kg to 6-7 kg. The case is usually metal; some manufacturers make ventilation holes in it for better cooling of the “filling” (mostly the transformer). There is a belt for carrying, and sometimes there is also a handle: the belt is put on the shoulder if the work requires movement.

One of the panels has a power button or toggle switch. The front part contains power and overheat indicators. There are also knobs for setting voltage and welding current. Also on the front panel there are two outputs - “+” and “-” to which working cables are connected. One cable ends with a clothespin clip, which is attached to the part, the second - with an electrode holder. The power cable connector is usually located at the back. That's all, actually.

When purchasing an inverter, make sure that the cables are long enough and flexible: this makes it easier to work with. It is the insufficiently long and rigid working cables that have the most complaints from users of the popular brand of inverter welding machines “Resanta”.

The general principles of working with an inverter welding machine are described in this video.

Welding with an inverter for beginners

As with any electric welding, the melting of the metal occurs due to the heat of the electric arc. It occurs between the welding electrode and the metal being welded. To create an arc, they are connected to opposite poles: “+” is applied to one, “-” to the second.

When connecting the electrode to the “minus” and the part to the “plus”, the connection is called “direct”. If “plus” is applied to the electrode, the connection is reversed. Both options are used when welding, but only for metals of different thicknesses: reverse - for welding thin metals; straight - for welding thick metals (more than 3 mm thick). But this is not an immutable rule; sometimes they do the opposite.

Direct and reverse polarity of connection on the welding inverter

What causes this division in practice? Physics of the process. When an arc occurs, the electrodes move from minus to plus. And at the same time they transfer their energy to the positively charged surface, increasing its temperature. Therefore, the element that is connected to the positive output heats up more.

When welding metals of sufficient thickness, they need to be heated well so that they melt and the weld is of high quality. That’s why they give “+” to them. Thin metal, on the contrary, can burn out due to overheating and a “minus” is attached to it, warming up the electrode more, from which more molten metal flows into the seam.

You can weld metal correctly with an inverter only if you have good control over the electrode. To do this, you need to take the holder correctly. How to do this, watch the video.

How a seam is formed during welding

To make the basics of welding with an inverter clearer, let’s look at what happens when a seam is formed. To begin with, let us clarify that a welding electrode for welding metals consists of a metal core and a coating - a special coating that protects the welding area from contact with oxygen contained in the air. Read more about electrodes for inverters here.


How to connect welding leads to a welding inverter

The inverter welding machine has gained wide popularity among home craftsmen and small repair shops. To obtain a strong and durable seam, a powerful and serviceable machine is not enough. High-quality wires for the welding inverter of suitable cross-section, type and length are also required.


Of the available metals, copper serves as the best conductor . Combined with its flexibility, this makes it an ideal material for making the base of welding wire - conductors.

The structure consists of the following main parts:

  • copper core, twisted from a large number of copper wires with a diameter of up to 0.5 mm;
  • separating layer - a thin shell that prevents the core and the insulation layer from sticking together, can be supplemented with talc or other powder;
  • an insulating coating consisting of rubber, rubber or other polymer.

The ends are provided with contacts to connect to the inverter and holder. They are crimped and soldered to ensure the best contact.


The most important characteristic required for a wire is its cross-section . It determines the maximum current passing through the cable. No less important is the resistance, which causes electricity losses on the way from the device to the electrode. Mechanical parameters are of great importance:

  • strength: ability to withstand loads;
  • elasticity: the ability to return to its original shape after deformation
  • temperature resistance: the ability to maintain working properties when temperature changes;
  • ability to withstand sunlight and humidity;
  • resistance to fungus and mold;


With household and semi-professional class inverters, the most common in home workshops, single-core wires of the KG brand are mainly used.

Depending on their purpose and characteristics, they are:

  • KG-HL , insulation is made of frost-resistant rubber, they work in the cold;
  • KG-T , insulation impregnated with substances that prevent the growth of fungus and mold, used in humid climates
  • KOG , highly flexible wires, for welding in hard-to-reach places, for example, in shipbuilding.

According to the number of cores they are divided into:


Most of the inverter wires are single-core.

One wire connects the device terminals to the electrode holder, the other to the ground clamp on the workpiece.


Used for high frequency welding and alternating current operation . Two cores have their own insulation; the outside is covered with another insulating layer. Alloys of copper and other non-ferrous metals are used as materials.


Such wires are used to connect automatic welding systems connecting pipelines and large containers.

Each core also has its own insulation.

Section selection

The correctly selected welding cable cross-section for the inverter will allow you to work safely and with the expected performance. If the wire cross-section is insufficient, the resistance of the wire will cause loss of current due to its heating; as a result, the machine will not be able to develop the required welding current and the quality of the seam will deteriorate sharply. In this case, the indicator on the inverter will blink , indicating an overload.

In order to connect low-power portable inverters operating from a 220V network, light and flexible wires with a cross-section of up to 16 mm2 are used.

For more productive devices, a cross-section of up to 50 mm2 will be required.

Correct connection

Proper connection ensures the welder productive and safe work.

Connecting wires to a welding machine requires compliance with a number of rules:

  • there must be a terminal at the end, crimped or soldered;
  • The wire cross-section must correspond to the maximum operating current of the device plus a margin of 20%
  • You should carefully monitor the polarity of the connection and observe it;
  • The cable must lie freely in the work area, without tension or loops.

How to connect a welding machine if there is not enough wire to the welding zone? You can increase its length.

Is it possible to extend the welding cable on the inverter?

When increasing the length, you need to understand that the longer the cable for connecting the welding inverter, the greater the losses and the lower the resulting current strength.

If it is necessary to weld at a great distance from the machine, wires of a larger cross-section should be connected to compensate for losses.

When splicing 380V cables equipped with terminals with a hole into a single circuit, they should be cleaned and securely connected with a bolt and nut, not forgetting to install large diameter washers. The connection point must be carefully insulated, taking into account the fact that the wire will be repeatedly pulled through metal and concrete.

How to connect an inverter if there is no crimped terminal on the cable? Wires are spliced ​​by repeatedly interweaving the wires that make up the core . Then the connection point should be soldered and crimped.

There are also special extension cables that have crimped and insulated connectors. Their type must match the connector of your device.

Manufacturers do not specify any restrictions on cable length. In each case, the welder himself decides what is better - to lengthen or drag the inverter and gas generator more often .

Marking of welding cables

The welding wire marking consists of several groups of letters and numbers. From it you can understand which model is in front of us.

First there are several letters indicating the type of cable.

After the type, a dash may indicate the climate class of the wire:

Next comes a number indicating the number of cores - 1, 2 or more. The designation is completed by the cable cross-section in mm2.

Safety requirements

When welding work, the following requirements must be observed:

  • Do not work with wires with damaged insulation or insufficient cross-section;
  • the wire in the working area should be placed freely, without clinging to the welder’s hands or feet;
  • there must be enough light in the working area for the welder to move confidently;
  • When connecting to the device, polarity must be observed.

Correctly selected wires for a welding inverter are the key to safe and productive work . You need to pay attention to the cross-section, length and climate class of the cable. Cable extension can be carried out in strict accordance with the requirements of the regulations.


How to properly connect a welding machine to the network?

Let's start with the fact that after purchasing his first inverter welding machine, a responsible consumer wants to study how it actually works.

The unit always comes with instructions, in which you can find, in fact, only a meager description of its operation in a few standard phrases, but you should understand that plugging in the plug into the network is not all the manipulations that should be done in order to get started welding work. And then the question arises - “ How to connect a welding machine ?”

An inverter-type welding unit is quite a complex piece of equipment, which has its own characteristics and operational nuances. Simply by connecting the inverter to an outlet, you can damage the device itself and lose wiring in the house.

This article will help you understand how to properly connect a welding machine to a 220 V network and what factors should be taken into account.


The main factor that should not be neglected is the integrity of the wiring and sockets in the house. It is also worth considering how long ago such wiring was laid, and what its service life is, the same applies to sockets. In most cases, if the wiring is more than 25 years old, there is a chance that it simply will not withstand a large amount of current, which will lead to irreversible consequences, and the use of a modern inverter with wires will become impossible.  

This means that before connecting the welding machine and starting work, you need to check whether the wiring in the house can withstand such loads. If the guarantees of this factor are not impressive, then we will tell you how to solve this problem.

Application of a current generator

Now let's look at solving the problem when connecting an inverter welding machine is impossible in your home due to questionable wiring. In this situation, it is worth using a third-party current generator.

Regarding this issue, many people remember that they already have such a device as, for example, a gasoline power generator, which is located somewhere in a garage or shed. Yes, an excellent solution in case of a sudden blackout, but it is not relevant for using a welding unit, since such a generator has insufficient power to provide a voltage of more than 5 kW for a long time.

And here again is the problem: using a gas generator to an inverter is impractical, and to make sure of this, it is worth finding out the power of the device required for welding work. To do this, you need to multiply the voltage value by the current that must be used for welding.

Let's consider the most common situation in welding - a 3 mm electrode, a current of 120 Amperes, a voltage of 40 V. When we multiply 120 by 40, we get a power of 4.8 kW. At the same time, taking into account the efficiency of the inverter, the required minimum power of the gas generator must be at least 6 kW. Thus, we come to the conclusion that such a solution is not optimal, but can be an alternative in cases where other options are not possible.

The ideal solution to this problem would be to purchase an electric welding machine with a built-in generator. Yes, such a unit has considerable dimensions and is much more expensive, but in a situation where the wiring needs to be better, the gas generator is of insufficient power or is completely unavailable, this option will be the most suitable solution.

There is also another way out to solve the voltage problem. In this case, you need to purchase a current stabilizer for the inverter, which can be connected directly to the device itself. This will be an ideal option for stabilizing the power grid.

Use of extension cords

Extension cords, strictly speaking, have nothing to do with the issue of connecting the welding machine, but this factor has a direct impact on the efficiency of the inverter, so it is worth discussing this topic in more detail. Incorrectly selected extension cables can lead to a decrease in voltage, and, as a result, to a decrease in the efficiency of the welding unit itself.

Why are extension cords needed for an inverter at all? The welding equipment includes sufficiently long cables (up to 2.5 m) and they are quite enough to carry out welding work, but what to do if there is a need to weld at height or you need to move around a fairly large area and carry the device, especially if it is quite large? dimensions, don’t you want? In this case, longer cables will help solve this problem without wasting time and effort.

Connecting wires to welding machines is not such a simple matter. It is necessary to accurately calculate the cross-section of the wire, on which its maximum power that it can withstand will directly depend.

Let's consider this situation using an example with such indicators as a welding current of 120 Amps, a wire cross-section of 2.5 sq. mm. produces 16 Amperes. Thus, in order to carry out welding work with a current of 120 amperes, a wire with a cross-section of at least 12 square meters is required. mm. According to the recommendations of experts, you need to use wires with a reserve cross-section.

It is also worth noting that when working with extension wires, it is imperative to untangle them before starting work - this way they cool down better and faster, and, of course, do not forget about grounding, which concerns basic and simple safety precautions when working with inverters.

An important point is that connecting several extension wires connected together is not the best solution, which can lead to a decrease in the efficiency of the inverter welding machine. It is better to determine in advance the required length of wire for optimal operation, which will also extend their service life, because the contact connections of the extension cord are more durable.


In order to use the welding machine correctly, you need to study the rules for preparing it for work and connecting it. By following all the recommendations, the welding process will become very simple and will bring not only benefits, but also pleasure. All basic rules also apply when connecting the inverter to a 380 V network and when using a transformer or semi-automatic device.

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We wish you good luck in welding and success in your achievements. Also, check out the rating of inexpensive welding inverters for work in the country or at home.


How to properly connect an inverter welding machine

Reading time: ≈5 minutes

So, you have purchased your first inverter welding machine. You will probably find an instruction manual included with it. Having carefully studied it, you will find that only a few general phrases are said about the correct inclusion. Is it really that simple? Plug the plug into the outlet and that's it? Alas, no.

An inverter-type welding machine is a complex device with its own nuances and features. By thoughtlessly plugging it into a household outlet, you risk losing the device itself or the wiring in the house. So how to connect a welding inverter correctly?

In this article we will briefly describe how to connect a welding machine to a 220 Volt home network and what should be taken into account.

How to connect welding cables to each other, connect to an inverter, clamp in a holder, extend, etc.

Quite often, welders have problems connecting cables . This question may arise for several reasons: the wire that comes with the welding machine is not long enough, or the cord was broken or damaged during work. Therefore, it is important for performers to know how to properly connect welding cables and extend them.

How to connect

It should be remembered that the safety of the performer and the quality of the work performed depend on the reliability of the contact connections of the conductors. The connections are subject to high technical requirements . But first of all, they must be resistant to shocks, tears and other mechanical influences. Therefore, it is very important to know how to connect two welding cables to each other.

The following are the most popular methods of connecting welding cables, each of which has its own advantages and disadvantages.

Let's look at the connection of welding cables in more detail.

1. The simplest way is to use additional accessories - welding connectors for connecting cables . They make work simple, fast and convenient. In addition, the use of connectors has a positive effect on equipment mobility.

There is a wide variety of these accessories on the market, differing in technical characteristics. Connection of welding cables: “male-female” - is a classification based on differences in the design of the connectors. You can find out how to choose the right detachable connections for welding cables and what you should pay attention to here.

2. The “twist” connection is the first and oldest method, characterized by fairly simple execution, quality and reliability.

Main disadvantages : this method is prohibited by a group of regulatory documents PUE (“Rules for the construction of electrical installations”); is an intermediate step before welding or soldering.

The prohibition of the PUE method does not prevent homemade workers from successfully using it, as shown in the video below.

“Twisting” can be done in several ways, which are presented in the pictures below. Regardless of the chosen method, the insulation of the cores should be removed by at least 3-4 cm. Then the sections of the cores must be treated with acetone or white spirit, cleaned with sandpaper and you can begin twisting.


There are also ways to connect welding cables if you have a certain set of equipment and additional accessories.

3. Soldering is a method of connecting cables by covering the heated ends of the wires with molten solder, which hardens and provides strength and high electrical conductivity of the connection. This method is used for small cross-section conductors.

Advantages: does not require special skills and specialized equipment compared to welding.

However, it is worth highlighting the disadvantages: a large number of preparatory operations, therefore, high labor intensity.

Before soldering, the conductors are cleaned of insulation and oxide film, then they are tinned, twisted and pressed with pliers. To avoid oxidation of the cleaned surface, fluxes should be applied to the treated areas.

Soldering of small copper wires is carried out using solder tubes filled with rosin or a solution of rosin and alcohol. These solutions are applied to the joint before soldering.

Then you can begin the soldering process: the joint is heated with a soldering iron or torch. Rosin or flux begins to boil, take a little solder onto the soldering iron tip and add it to the soldering zone by pressing the tip against the conductors. The solder spreads and fills the gaps between the wires, thereby creating a connection. If a torch is used, the solder is added to the torch.

After the soldering process is completed and the workplace has cooled, the flux residues must be washed off, the joint dried, coated with a special varnish, and insulated with tape or heat-shrinkable tubing.

4. Crimping is the process of connecting wires using copper or aluminum sleeves. It is necessary to select a sleeve depending on the size of the “twist” and the cable material (copper or aluminum).

The wires must be cleaned to a metallic shine, bundled/twisted, and then a sleeve is put on them and clamped with special pliers. In this case, the walls of the sleeve are pressed into the conductor conductors and a reliable electrical contact is formed.

Advantages : high reliability; no high demands are placed on the performer regarding his qualifications; independence from the availability of electricity.

Disadvantages: rigid sleeve leads to wire rupture near the sleeve; it is necessary to have a supply of sleeves of various sizes; if the connection is larger than the diameter of the cord, the cable will touch surrounding objects.

How to connect to an inverter

The question of how to properly connect cables to a welding inverter arises when deciding on polarity when welding with direct current: forward or reverse.

The “plus” sign is connected to the electrode holder, the “minus” sign is connected to ground - welding is performed with reverse polarity . In this case, the current moves from the electrode to the workpiece, the metal heats up more than the electrode.

The “minus” sign is connected to the electrode, the “plus” sign is connected to ground, therefore, the polarity is straight. The current flows from the workpiece to the electrode, creating stronger heating of the electrode.

Which polarity should be used depends on several factors: the type of metal; workpiece thickness; electrode type.

More detailed information on how to connect cables to a welding inverter depending on the selected polarity is presented in the corresponding article.

You should also pay special attention to the basic rules for connecting welding cables to inverter-type equipment. These nuances will guarantee a safe and comfortable work process.

Reading this information will help you learn how to connect welding cables to a specific type of equipment.

How to hold it in a holder

The method of fixing the welding cable depends on the type of electrode holder : homemade or purchased (produced by companies of the corresponding profile).

Types of homemade holders and methods of assembling them, their main advantages and disadvantages are discussed in the article “Electrode holder for a welding machine.” This article also presents a method for correctly and securely connecting the cable to the electrode holder.

You should also pay attention to the recommendations of the master , who will help you make a professional, competent holder yourself. For clarity, a video of the assembly of the holder is presented.

To understand how to connect welding cables to the purchased holder , we recommend that you watch the video below. The performer can clearly see that the cable, together with a metal gasket (plate), is inserted into the corresponding hole and securely fixed with a key by tightening the screws.

How to extend the cable on an inverter

Typically, the inverter is equipped with a wire no more than two meters long. Working with such a cable is quite problematic and inconvenient. Therefore, performers often have a question: how to extend the cable on a welding machine ?

Previously, we considered that connecting welding cables should be done in several ways, each of which is used depending on the skills of the performer, the presence or absence of specialized equipment and additional accessories.

Advice! In most cases, the owner of the welder connects the welding cables for the holder and the ground into one longer wire and uses it to connect to the ground . And for the electrode holder, the welder buys a part of the cable of the required length .

It is important to know how to extend a welding cable. The connection of welding cables during extension can be performed using the following methods: welding; soldering; crimping.

It is also worth noting the opinion of some professionals who are against lengthening the conductors . Cables that are too long may adversely affect the performance of the device. In addition, the longer the wire, the greater the current loss, which can negatively affect the quality of welding.

How to choose a welding cable

Equipment of any type will serve its owner for a long time if the wire is selected correctly. When choosing a conductor, you need to pay attention to the following points :

  • the cable must meet the technical requirements for it: resistance to impacts, breaks, bends, aggressive chemical environments, temperature changes, ultraviolet radiation, mold formations;
  • The cord must withstand the maximum current that the welder’s unit produces.

More detailed information is presented in the articles on KG, KOG cables, as well as in the publication on conductors for the inverter.

How to find out the cross section

The main technical characteristics of conductors: cross-section, diameter and other important properties are indicated in catalogs or corresponding descriptions. However, if the contractor does not have the opportunity to familiarize himself with this data, and the question of how to determine the cross-section of the welding cable needs to be answered, then you should remember some recommendations.

There are several ways to determine the cross-section of a conductor. They all boil down to the fact that first you need to calculate the diameter of the core. This can be done using a micrometer or caliper. However, the simplest method, which does not require special accessories, is to use the following method.

The contractor will need to remove the insulation from the conductive core. Then you need to wind the core around a cylindrical object (screwdriver) and use a ruler to measure the total length of the turns, the number of which for accurate calculations should exceed 10. In conclusion: the total length in mm. must be divided by the number of turns. The resulting value will be the diameter of the wire, from which the cross-sectional value can be found.

The contractor can find complete information about the cross-sections of cables of various brands in articles devoted to this topic:

  • “Welding cable KG”;
  • “Welding cable KOG.”


Connecting the welding machine to the electrical network: rules and algorithm, safety precautions

Surely, after purchasing an inverter welding machine, in the box you will find instructions for operating the device. After reading it, you will most likely notice that proper connection to the network will be mentioned in passing.

And in vain, because the matter is not limited to simply inserting a plug into a socket.

It is dangerous to carelessly connect such complex equipment to your home network without taking into account its properties and nuances. As a result, you can easily destroy the welding inverter itself or the wiring in the building. What do you need to know about properly connecting a welding machine?

Below we briefly summarize the main points that you should pay attention to when connecting a welding inverter to a 220V household outlet.

Preparing to connect

Before connecting the welding inverter, you should make sure that the wiring in the building is suitable for welding work. First of all, inspect the outlets.

If they were installed more than a quarter of a century ago, then there is a good chance that the wiring has not changed since then. It’s good if it can withstand high voltage, but this is rather an exception to the rule.

Usually such wiring only adds difficulties to the work. In this case, you will not be able to work with a modern inverter machine, even using the latest welding cables.

You don't have to have an engineering degree to imagine the consequences of connecting a powerful inverter to an old outlet.

You risk cutting off power not only to your workspace, but also to neighboring buildings, and electrical appliances may become unusable.

Before starting work and connecting the inverter, it is necessary to check the condition of the wiring. Don't give up if you find out that your wiring may not be able to handle the load.

You can get out of this situation by using a current generator. How to do this is described below. Now we suggest considering options for connecting an inverter welding machine to the network.

Using Generators

If the wiring test result is unsatisfactory, connecting the inverter is unacceptable. But there is always a way out. Electric generators can be used.

Many people have gas generators that can help out in the absence of electricity. In theory, their use may seem like a great idea.

In fact, it turns out that such generators have low power, and supplying a voltage of more than 5KW is an impossible task for them.

Obviously, there is no point in connecting an inverter device to a generator with low power. The minimum required power value can be found by multiplying the cooking current by the voltage value.

Let's consider a standard connection diagram. When welding with a 3 mm electrode and a current of 120A and a voltage of 40V, you need to multiply 120 by 40. This means the required power value is at least 4.8 kW.

Considering that the efficiency of the inverter is less than 100%, for stable operation of the welding machine you will need at least 6 kW.

So, a gasoline generator can be used when no other power source is available. It is more logical to check the wiring at the planning stage of purchasing an inverter device.

If it does not meet the requirements, there is a solution to purchase a device with an already built-in generator. The only disadvantages of these models are the price and large dimensions. But sometimes there is no other way to solve the problem.

If this option is not relevant for you, pay attention to the current stabilizer for the welding inverter. You can connect the device to it in a relatively stable network.

Selecting extension cords

Particular attention should be paid to the use of extension cords when connecting inverters to the network. If the extension cord is incorrectly selected, the efficiency of the welding inverter decreases and the voltage drops.

The configuration of welding machines usually includes a cable about 2.5 m long. For simple work, this length is enough, but in case of frequent movement or welding at height, it will not be enough.

Therefore, it will not be superfluous to learn about connecting extension cables. Under no circumstances connect them at random! You will need to calculate the exact cross-sectional size of the extension cable.

This value is directly related to the maximum power that the wire can withstand.

Using the above diagram, let's give an example. The current we need when welding is 120A. We get 16A when using a cable with a cross section of 2.5 sq. mm.

Proportionally, for a welding current of 120A, the cross-section of the extension cable must exceed 12 sq. mm. Do not forget about safety precautions, remember about grounding and untangle the cables before starting welding, for faster cooling.

It is much more efficient to buy one cable of the required length than to connect several short ones to each other. This way, the contact connections of the extension cord will be more durable, and the possibility of losing the efficiency of the welding inverter will be reduced.


The described technology for connecting an inverter welding machine to the network is simple.

It is worth understanding the importance of these rules, remembering them and successfully applying them in practice in the future.

When connecting a transformer, semi-automatic device or 380V device, the sequence of actions is the same. Successful work!


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