Common problems and troubleshooting of pipe fitting hot-melt welder in practical operation: for new or unused butt fusion welding machine and pipe fitting hot-melt welder accessories, the grounding resistance between winding resistance and between winding resistance and shell is greatly reduced due to moisture return, which is very easy to produce short-circuit fault and grounding device at the beginning of application, resulting in machine equipment and safety accidents.Before application, use a megger to check whether the grounding resistance meets the standard. Before starting the hot-melt welding machine for new pipe fittings, check whether part of the AC contactor of the circuit system is excellent. After everything is considered normal, start the test run under full load. When it is confirmed that there is no potential safety hazard of electrical equipment, the test run can be carried out under load. The specification and model of pipe fitting hot-melt welding machine can be invested in all normal operations. If there is a common failure of the pipe fitting hot-melt welding machine, first look at the problem of airport pick-up. If the switching power supply is not connected, it is the problem of fuse tube burning or power supply. The spare parts must be replaced or the wiring must be started from scratch. After the power supply is connected, the display screen does not appear, the screen flickers and the equipment buzzes. It may be that the display screen is damaged, which is caused by facing, heat, collision, embrittlement and the wiring falls off. The pipe fitting hot-melt welding machine shows that this problem is wiring and replacing the display screen from the beginning. The current of pipe fitting hot-melt welding machine can not rise because of the undervoltage protection of external switching power supply and the laying of power plug is too long. It is required to query the external wiring and lay it from scratch. The reason why switching power supply can not work normally according to the set main parameters is that the basic parameters of a section of current are too low. The way is to increase the main parameters of a section of current for less than 30s, and then continue to carry out electric welding of all normal main parameters.