The coil of blower motor with stable quality burns unevenly, and it burns black or scorched one by one. Professionally speaking, the polar winding at the end of the winding is burnt black or dark brown, while the other two-phase windings are intact or slightly burnt, that is, the burnt state is burnt black diagonally in sections, not in circles. Actually, there are many reasons that cause the blower to run out of phase, such as bad connection between the cable and the outgoing line, burning out one phase, fusing one phase of the power fuse, insufficient strength of the cable connection nose, and the running current of the blower out of phase is larger than the rated current. If the protection does not work, the motor winding will burn out due to overheating.

2. Inter-turn short circuit

At the end of the blower coil, it can be clearly seen that there are several turns or one turn or one pole group burnt, and this part of the electromagnetic wire is often burnt as bare copper wire, while the phase or other two-phase coils except the short-circuit part are relatively intact or slightly burnt, which is usually caused by circuit problems or long-term overload operation of the blower resulting in motor burning.

3. Short circuit between phases

The interphase short circuit occurs at the winding end, and the interphase insulation gasket at the winding end is low in strength or damaged. When the blower motor is heated or damp, the insulation of these weak parts decreases and then breaks down to form interphase short circuit. There have also been cases where the connecting sleeve of the bridge line of the blower is improperly handled or burnt, and the bridge line joint collides with each other, resulting in phase-to-phase short circuit.

 In addition, for example, the blower sucks in foreign matters, which causes the motor to jam and run poorly, and even causes the motor to burn. If the impurities are conductive and fall into the motor, it will cause the motor to burn in short circuit. In some cases, the blower is overloaded or the air inlet and outlet are blocked and the main line of the motor is burnt out, which leads to the motor not working normally. Therefore, the air inlet and outlet of the blower must be kept unobstructed during use.