Minimum input voltage
The minimum actual input voltage at which the welding machine remains operational.
Such information is useful primarily for working in unstable networks, where the voltage tends to “sag” a lot, as well as from autonomous power sources (for example, generators), which can also produce voltage below the nominal one.
Power consumption
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.
Open circuit voltage
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.
Min. welding current
The smallest current that the device is able to supply through the electrodes during operation. For different materials, different thicknesses of the parts to be welded and different types of welding itself, the optimal welding current will be different; there are special tables that allow you to determine this value. The general rule is that a high current is far from always useful: it gives a rougher seam; when working with thin materials, it is possible to melt through the junction instead of connecting the parts, not to mention excessive energy consumption. Therefore, if you have to work with parts of small thickness (2-3 mm), before choosing a welding machine, it makes sense to make sure that it is capable of delivering the desired current without “busting”.
Duty cycle
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%.
Protection class (IP)
The protection class to which the housing of the welding machine corresponds.
This parameter is traditionally denoted by the IP standard with two digits. It characterizes how well the case protects the hardware from foreign objects and dust (first digit), as well as from moisture (second digit). It is worth noting that in welding machines the degree of such protection is usually small — this is due to the fact that the case must be made ventilated. Here are the levels of protection against solid objects / dust that are relevant for modern models:
1 — protection against objects larger than 50 mm (comparable to the size of a human fist or elbow);
2 — from objects larger than 12.5 mm (we can talk about protection from fingers);
3 — from objects larger than 2.5 mm (the probability of accidental hit by most standard tools is excluded);
As for protection against moisture, it can be generally zero — that is, such a device can only be used in dry conditions. However, there are more advanced options:
1 — protection against drops of water falling vertically, with a strictly horizontal position of the device (the minimum degree of protection, in fact — from accidental ingress of a small amount of moisture);
2 — from vertical drops of water when the device deviates from the horizontal up to 15 ° (slightly higher than the minimum);
3 — from splashes falling at an angle of up to 60 ° to the vertical (we can talk about protect...ion from rain);
4 — from splashes falling from any direction (possibility of use in rain with strong winds);
Sometimes, instead of one of the numbers, the letter X is put — for example, IP2X. This means that the protection class for the corresponding type of exposure is not defined. In such a case, it is best to assume that there is no protection at all — this will provide maximum security and avoid unpleasant surprises.
Electrode holder cable
The length of the electrode holder cable supplied with the device.
As the name implies, this cable is used to connect the clamp for the welding electrode to the machine. The longer such a wire is, the more freedom the welder has in moving, the farther he can go without moving the machine itself. On the other hand, excessively long cables create problems in storage and transportation, and often during operation (you need to look for a place where to place the excess wire). Therefore, when choosing, you should proceed from what is more important for you: the ability to move away from the device or the overall compactness. As for specific numbers, most often the length of this wire varies from 2 to 3 m, but in some models it can reach 5 m.
Mass cable
The length of the ground cable supplied with the machine.
The mass cable is a wire that is connected to the workpiece with a clamp. In other words, this is the second contact required to close the circuit during electric welding; connecting such a wire actually turns the workpiece into one solid fixed electrode (paired with a movable welding electrode). As for the length of such a wire, the longer it is, the farther from the connection point you can place the machine and the more freedom of movement the welder gets. On the other hand, excessively long wires create problems in storage and transportation, and often during work (you need to look for a place where to place the excess cable). In addition, freedom of movement can be ensured by increasing the length of the second wire — for the electrode holder or burner. Thus, the mass cable in modern welding machines usually has a length of 1.2 to 3 m (with some exceptions — both smaller and larger). This length allows you to comfortably place the device and at the same time does not create problems.
Case (bag) included
The presence of a
case or bag for storage and transportation in the scope of delivery of the welding machine.
Cases are characteristic hard containers in the form of a suitcase; such containers provide excellent protection against moisture and dirt, as well as against impacts. Bags, in turn, are made soft; they are inferior to cases in terms of the quality of protection, but they are less bulky and can be folded quite compactly when not needed. Well, anyway, complete packaging usually turns out to be more convenient and practical than impromptu.
