Comparison Paton MFI-250S MultiPRO vs Paton PSI-250R-380V (5-2)

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 na...me). As 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 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.

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 welding current at which the machine is able to operate with a duty cycle of 100%.

See below for more information on the frequency of inclusion (PV). Here we recall that “100% duty cycle” means continuous operation, without shutdowns for cooling. Thus, the maximum welding current at 100% duty cycle is the highest current at which the machine can be used without interruption. Usually, this current is much lower than the maximum.

The location of the wire feed spool.

The wire is used in semi-automatic welding (see "Type of welding"); the coil on which it is wound can be located both outside the device and inside. There is no fundamental difference in the design of the feed mechanism, in efficiency and in other operating parameters between the "external" and "internal" models, they differ mainly in the features of storage and transportation. For example, the built-in coil increases the size and weight of the entire device, but it does not need to be carried separately.

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.