Versatility is the main advantage of a welding semiautomatic device in comparison with a conventional welding transformer. In addition to ordinary carbon steel, they can also cook stainless steel, cast iron, aluminum and other non-ferrous metals. A large number of semi-automatic welding models are available on the market, differing in characteristics, functionality and price. A person buying the first semiautomatic device in his life, this abundance can confuse.
Instruction manual
1
First of all, determine what maximum welding current you will need to complete your work. This parameter is basic for any welding machine, it determines the thickness of the metal being welded. There is the following dependence of the welding current on the thickness of the metal: for welding metal with a thickness of 1.5 mm, a current of 35-50 A is required, for 2.0 mm - 45-80 A, for 3.0 mm - 90-130 A, for 4, 0 mm - 120-160, for 5.0 mm - 130-180 A. Adjustment of the welding current in the devices can be discrete and smooth. The latter allows you to select the welding current more accurately.
2
Define power options. If you have only a single-phase voltage of 220 V, the purchased device should be able to be connected to a single-phase network. It is necessary to choose a device with such a range of supply voltage that covers the voltage drops of the network. Typically, welding machines operate normally with voltage fluctuations within 15%. The parameters of the supply network should be taken into account when choosing the power of the device. Not all networks can withstand high power devices - more than 5 kW.
3
You need to know with what intensity the semiautomatic device will work. This parameter is determined by the PV characteristic - the on-time, which is calculated by the formula PV = Tsv ∙ 100 / Tsv + Tp, where Tsv is the time of continuous welding, Tn is the pause time. The PV value is obtained as a percentage. Most amateur welding machines are designed for intermittent modes. After a welding period of usually 5 minutes, a pause should follow.
4
Semiautomatic devices are conventional and inverter type. The latter has an advantage over the former in welding quality and ease of use. Thanks to more precise adjustment of the welding current, the arc burns more stably, there is a system to prevent electrode sticking and a hot start (Anti-Stick and Hot Start functions), and there is a thermostatic overload protection. Inverters are smaller and lighter than conventional welding machines. Preference when buying should definitely be given to them - in case the price level is not a determining condition when choosing.
5
Pay attention to the degree of versatility of the semiautomatic device. There are models that work only with electrode wire - flux-cored, working without gas, and ordinary, working in a protective gas environment (MIG / MAG welding). There are also universal models that allow you to work with piece electrodes - MMA welding. The second, of course, is more expensive.
6
Devices differ in the degree of automation. In conventional models, the wire feed speed is manually adjusted. In synergistic devices, the wire speed is automatically adjusted depending on the strength of the welding current and the parameters of the arc burning. Work with synergistic semiautomatic devices turns out to be of better quality and more convenient, however, they cost much more than conventional devices.
7
For comfortable work, the compactness and weight of the semiautomatic device matter. On sale are two-case heavy models and lighter single-case. If mobile use of a semiautomatic device is supposed, it is better to give preference to the single-case light device.
8
When buying a machine, see how quickly it gets ready for use, whether the control elements are conveniently located - the knobs for adjusting the welding current and wire feed speed, how long the feed sleeve and cable are (the longer, the better). Check out the equipment, the number of spare contact tips, the volume of the gas bottle, etc.
9
Do not disregard the manufacturer. Semiautomatic machines of western firms, in particular, Italian ones, work very reliably. It cannot be categorically argued that cheaper semiautomatic devices of Chinese manufacturers are clearly worse than their western competitors, but there is no doubt a certain amount of risk when buying Chinese equipment.
