Comparison Edon MIG-315 vs Telwin Artika 220

The type of welding machine determines the features of its design and purpose.

— Transformer. The simplest type of welding machine. The principle of operation in this case is as follows: the input mains voltage is fed directly to the transformer winding, which lowers it to the open circuit voltage (see below). In addition to alternating current, transformers can also cook on direct current — in such models, the simplest rectifier with a stabilizer is usually used; when using alternating current, its frequency remains the same as in the network. The main advantages of transformers are high reliability combined with low cost and simplicity of design. At the same time, the functionality of such devices is rather limited — in particular, of the types of welding, there are rarely any other than manual arc welding (see "Type of welding"); and the quality of work is relatively low due to the instability of the current supplied to the electrode. Yes, and the weight of transformers, compared with inverters, is quite high. In general, this type of welding machine is intended mainly for simple work that does not require high precision.

— Inverter. A type of welding machine designed to overcome some of the major disadvantages of transformers, such as heavy weight and uneven seams. The key difference between inverters is that the current to the winding of the step-down transformer is not supplied direc...tly from the network, but through special control circuits (which, in fact, are an inverter in the narrow sense of the word). When passing through these circuits, the current is first converted to direct, and then back to alternating, but with an increased frequency of the order of tens of kilohertz (for comparison, the frequency of household alternating current is 50 Hz), and this high-frequency current is already supplied to the winding. This made it possible to significantly reduce the dimensions of the transformer coils and thus reduce the weight and dimensions of the entire device — many inverters can be safely carried on a shoulder strap. A high frequency provides a much more stable arc and a quality weld both when welding with alternating current and when using direct current (for both options, see the “Welding Current” paragraph for more details). In addition, this scheme allows the use of almost all modern types of welding (see below). Among the disadvantages of inverter devices, one can note the high cost due to the complexity of the design. However, if you need a device for high-quality professional welding, you cannot do without an inverter.

— Semiautomatic. This term refers to a type of welding transformers (see above), in which the welding process is partially automated. The electrode for a semiautomatic device has the form of a thin wire (usually not thicker than 1.2 mm) wound on a coil; during operation, this wire is fed to the nozzle automatically, as it is consumed. This is much more convenient than with conventional welding — after all, the operator does not have to control the length of the electrode himself and adjust it manually, the electrode itself has to be changed much less often, and semi-automatic welding also has some other advantages (for more details, see "Type of welding"). Otherwise, semiautomatic devices are completely similar to conventional transformers.

— Semi-automatic inverter. As the name implies, this category includes inverter-type machines with an electrode supply system typical for semi-automatic machines. For more details, see the relevant paragraphs above, but here we note that this option can be called the most advanced among modern general-purpose welding units.

Among the main types of welding can be called manual arc (MMA), semi-automatic (MIG / MAG), argon-arc (TIG), spot (SPOT), spot (STUD) and plasma cutting (PLASMA) welding.

— MMA. Welding using an electric arc and a consumable electrode with a special coating. The electrode is fed and moved manually by the welder. Shielding gas supply is not provided; protection of the weld pool from air can be carried out due to the combustion of the coating deposited on the electrode. This welding technology allows the use of the simplest equipment, it is undemanding to the quality of the current and the design of the welding machine. On the other hand, the quality of the resulting weld is highly dependent on the skills of the welder, the productivity of the process is relatively low, and this technology is poorly suited for non-ferrous metals — its main purpose is the welding of steel and cast iron.

— MIG/MAG. Partially automated welding in an inert (MIG) or active (MAG) gas environment. The gas enters directly to the place of welding through the burner and, when the arc burns, forms a protective sheath that covers the weld pool from exposure to air. And the term "semi-automatic" means that filler material in the form of a thin wire is also automatically supplied to t...he place of work (but you need to move the burner manually). The choice between inert and active gas is made depending on the materials being welded — for example, the first option is usually used with non-ferrous metals, the second with steel. Such welding provides a much better quality of the seam than manual welding, and also increases the convenience and speed of work — in particular.

— TIG. Manual welding with a non-consumable electrode in an inert gas environment. With such welding, the electric arc melts only the edges of the parts to be joined, and the final seam is formed from them, without using the electrode material (in some cases, additives in the form of pieces of metal of the appropriate shape can be used). To protect the seam from exposure to air, a protective gas, usually argon, is supplied to the heating point. TIG welding is well suited for stainless steel as well as copper and aluminium alloys. It allows you to create a more accurate seam than the same MMA, and more precisely control the process. On the other hand, this technology is quite demanding on the skills of the welder, and the speed of work is relatively low.

— SPOT. Electric welding, carried out due to the point impact of high currents. It is used for connecting thin sheets of metal (mainly up to 3 mm), as well as for attaching pins and studs to a flat base. When connecting sheets of metal, two electrodes with a relatively small diameter tightly press the workpieces against one another, after which a current is passed through them with a force of the order of several kiloamperes; the metal at the point of contact is heated to the melting point, which ensures the connection. When attaching pins and studs, the role of one of the electrodes is played by the pin itself, the role of the second is played by a flat base. SPOT type welding is very popular in car manufacturing and car service: it is in this way that some elements of car bodies are connected, and it can also be useful for straightening. There are unilateral and bilateral. The first uses a single electrode, which is pressed against the workpiece with force. The main advantage of this option is the ability to work with surfaces that are accessible only from one side — for example, car doors. Actually, one of the main areas of application for one-sided SPOT welding is a car service, in particular, straightening car bodies and other car surfaces. The second welding (two-sided) involves the use of a pair of electrodes that compress the junction from both sides, like a vice. This variant is better suited for work with thick parts or where a high reliability of the connection is required — due to the compression described, it is easier to achieve the desired depth of the weld pool. On the other hand, its use requires access to both sides of the workpiece. Note that some models of welding machines are able to work according to one and the other scheme; this makes the device very versatile, but may come at a cost.

— STUD. Spot welding technology using a lifting (pulling) arc. Mainly used for flat base plus stud connections. The welding process itself takes place in the following way: the stud is pressed against the base; the current is switched on; the pin rises; an arc ignites between it and the base, which melts the surface of the base; the hairpin is lowered into the melt; the current is turned off, the metal freezes. STUD welding involves the use of mechanized welding torches with a spring or hydraulic system that raises and lowers the stud, and an inert gas or flux is used to protect the joint from atmospheric air.

– PLASMA. Cutting metal using a stream of heated plasma — a highly ionized gas. To do this, gas (inert or active) is supplied to the place of work, which, due to the influence of an electric arc, is ionized, heated and accelerated. The plasma temperature can exceed 10,000 °C, and the speed is 1,000 m/s, which makes it possible to work with almost any metals and alloys, including refractory ones. At the same time, cutting is carried out quickly, the cut is clean and neat, and the cutting depth can reach 200 mm. The main disadvantage of plasma cutting is the high cost of equipment.

The type of current used by the machine directly in the welding process.

— Variable. A kind of current that is familiar to many primarily from ordinary household sockets: it has an interchangeable polarity, the “plus” and “minus” on the contacts change places with a high frequency. For example, in a household network, the frequency is 50 Hz, and at the output of inverter devices (see "Type") it can rise to several tens of kilohertz. The main advantage of alternating current is that the concept of “polarity” does not apply to it and it is impossible in principle to confuse it when connected. At the same time, the constant reversal of the current direction increases the amount of welding spatter and reduces the quality of the weld. This shortcoming is partially eliminated in the mentioned inverters, due to high frequency currents, however, the quality of welding with alternating current is still somewhat lower than when using direct current. As a result, this option is most widely used in manual arc welding (see "Type of welding") of ferrous metals, in other cases it is rare or not used at all.

— Permanent. A current that has a constant direction — from one pole to another, without changing them (similar to how this happens, for example, when using batteries). Such a current, due to its uniformity, creates much less spatter than alternating current, and provides a better quality of the seam....It is also better suited for stainless steel, non-ferrous metals and some specific applications (eg semi-automatic welding, see Welding type). However, as for batteries, the concept of polarity is relevant for direct current devices: “minus” can be connected both to the electrode (so-called direct polarity) and to the material being welded (respectively, reverse). Each of the options is used for certain materials and types of work, so when using direct current, you also have to pay attention to the correct connection. In addition, the direct current devices themselves are more complicated and expensive due to the need to use rectifiers.

— Variable/constant. Devices capable of using both of the above types of current in operation. They are the most versatile, however, and cost accordingly.

The voltage of the power source to which the welding machine is designed to be connected. Note that the most common options today differ not only in voltage as such, but also in the features of the connection itself:

— 1 phase(230 V). The voltage used in normal household sockets. Welding machines for 230 V are by far the most widespread: such power is enough to operate models of both low and medium power, and finding an outlet is usually not a problem. The only limitation on their use is that the power consumption is usually quite high, which increases the load on the power grid accordingly. Therefore, high-quality electrical wiring is required for connection, and for models with more than 5 kW, it may also be necessary to connect directly to the shield. The term "single phase" means that one pair of contacts "zero" — "phase" is used when connecting.

— 3 phases(400 V). This voltage is used in specialized production facilities: workshops, workshops, etc.; outside of such premises it is very rare. The 400 V network provides more power than 230 V, however, such power is not needed very often — usually for the largest jobs with complex and/or thick materials. Three-phase devices are not compatible with ordinary household sockets, not only because of the low voltage in the network, but also by the connection method — this requires three pairs of “zero” — “phase” contacts (hence the name). A...s a result, pure 400V models are not widely used — mostly industrial grade devices for which high power is critical.

— 1 phase (230 V) / 3 phases (400 V). Universal devices capable of working with both of the above input voltage options. To date, most models with the ability to work from three phases belong to this particular variety. Note that this can include both high-power devices, where single-phase power can be called a “backup option in case of emergency”, and portable low-power units — in them, respectively, three phases are already an additional option for maximum versatility.

The maximum power consumed by the welding machine during operation, expressed in kilowatts (kW), that is, thousands of watts. In addition, the designation in kilovolt-amperes (kVA) can be used, see below for it.

The higher the power consumption, the more powerful the current the device is capable of delivering and the better it is suitable for working with thick parts. For different materials of different thicknesses, there are recommendations for current strength, they can be clarified in specialized sources. Knowing these recommendations and the open circuit voltage (see below) for the selected type of welding, it is possible to calculate the minimum required power of the welding machine using special formulas. It is also worth considering that high power creates corresponding loads on the wiring and may require connection directly to the shield.

As for the difference between watts and volt-amperes, the physical meaning of both units is the same — current times voltage. However, they represent different parameters. In volt-amperes, the total power consumption is indicated — both active (going to do work and heat individual parts) and reactive (going to losses in coils and capacitors). This value is more convenient to use to calculate the load on the power grid. In watts, only active power is recorded; according to these numbers, it is convenient to calculate the practical capabilities of the welding machine.

The voltage supplied by the welding machine to the electrodes. As the name suggests, it is measured without load — i.e. when the electrodes are disconnected and no current flows between them. This is due to the fact that at a high current strength characteristic of electric welding, the actual voltage on the electrodes drops sharply, and this does not make it possible to adequately assess the characteristics of the welding machine.

Depending on the characteristics of the machine (see "Type") and the type of work (see "Type of welding"), different open circuit voltages are used. For example, for welding transformers, this parameter is about 45 – 55 V (although there are higher voltage models), for inverters it can reach 90 V, and for semi-automatic MIG / MAG welding, voltages above 40 V are usually not required. Also, the optimal values \u200b\u200bdepend on type of electrodes used. You can find more detailed information in special sources; here we note that the higher the open-circuit voltage, the easier it is usually to strike the arc and the more stable the discharge itself.

Also note that for devices with the VRD function (see "Advanced"), this parameter indicates the standard voltage, without reduction through VRD.

The highest current that the welding machine is capable of delivering through the electrodes during operation. In general, the higher this indicator, the thicker the electrodes the device can use and the greater the thickness of the parts with which it can work. Of course, it does not always make sense to chase high currents — they are more likely to damage thin parts. However, if you have to deal with large-scale work and a large thickness of the materials to be welded, you simply cannot do without a device with the appropriate characteristics. Optimum welding currents depending on materials, type of work (see "Type of welding"), type of electrodes, etc. can be specified in special tables. As for specific values, in the most “weak” models, the maximum current does not even reach 100 A, in the most powerful ones it can exceed 225 A and even 250 A.

The duty cycle allowed for the welding machine.

Almost all modern welding machines require breaks in operation — for cooling and general "recovery". The frequency of inclusion indicates what percentage of the time of the total work cycle can be used directly for work. In this case, 10 minutes is usually taken as a standard cycle. Thus, for example, a device with a duty cycle of 30% will be able to work continuously for less than 3 minutes, after which it will need at least 7 minutes of interruption. However, for some models, a cycle of 5 minutes is used; these nuances should be clarified according to the instructions.

In general, high frequency is required mainly for high-volume professional work; with a relatively simple application, this parameter does not play a decisive role, especially since you have to take breaks during work. As for specific values, the mentioned 30% is a very limited figure, typical mainly for entry-level devices. A value of 30 – 50% is also low; in the range of 50 – 70% is the majority of modern devices, and the most "hardy" models provide a frequency of more than 70%.

The largest diameter of the electrode that can be installed in the welding machine. Depending on the thickness of the parts, the material from which they are made, the type of welding (see above), etc. the optimal electrode diameter will be different; there are special tables that allow you to determine this value. Large diameter may be required for thick materials. Accordingly, before purchasing, you should make sure that the selected model will be able to work with all the necessary electrode diameters.

In modern welding machines, an electrode diameter of 1 mm or less is considered very small, 2 mm — small, 3 mm and 4 mm — medium, and powerful performant models use electrodes of 5 mm or more.