Working principle of electric welding machine: When the electric welding machine is in contact with the welded object and the welded object, a short circuit occurs, and the short circuit generates a high-temperature arc, which melts the welded object and makes it merge with each other. The welding machine uses the thermal effect of current to complete the above welding. The circuit is closed, and the current in the circuit is equal everywhere, but the resistance is the largest at the contact surface between the welded object and the welded object. According to the formula, the heat generated here is also the highest, and the melting point of the welded object is also low, which can be melted at high temperature to achieve the purpose of welding.

Matters needing attention in purchasing electric welding machine

First, when purchasing welding machine products, you should go to regular production enterprises or big shopping malls to buy them, and also buy brand-name products with high market share. Don't go to small shops to buy cheap ones, because the quality of welding machines there can't be guaranteed.

Second, when purchasing, check whether the nameplate on the product has the manufacturer's name, production address, specifications, welding current adjustment range, load duration and input voltage and current, and then determine the welder you want to buy according to the work needs.

Three, when buying, you can ask the dealer to provide product quality inspection report or certificate. Because the welding machine product is a national compulsory certification product, it is necessary to confirm whether the product has passed the "3C" certification when purchasing. You can also check it online.

Four, when buying, be sure to check whether the product has a grounding screw, and the joint of the grounding screw should be well grounded without paint. Whether the movement is clean and the insulation is damaged to ensure the safety of use. If necessary, it can also be tested.

5. Before buying, check the operation, conversion and installation of the switch on the panel, whether the power indicator light is on or off, whether the fan is normal, whether there is abnormal vibration and buzzing in the power supply part, whether there is abnormal smell, whether there is discoloration in appearance and other heating phenomena, so as to ensure the quality of the welding machine and give full play to its performance.

Six, if you want to buy a gas shielded welding machine, before buying, you should also check whether the accessories are complete, whether the wire feeder is greasy, whether the rotation is smooth, whether the connecting cable matches the external insulation and whether there is any damage, so as to ensure the stability of the arc.