In the process of dissecting motor winding faults, it was invariably found that the first coil of the winding was more likely to have a problem. We have touched upon this issue to some extent in other articles, but have not conducted a systematic analysis specifically targeting the first coil.
An electric motor winding consists of several coils. Some motors use individual coils connected by wiring, while many motor manufacturers, to avoid potential connection quality issues during coil connection, use a method of continuously winding the same phase winding. The first coil embedded into the iron core is called the first coil.
The first coil has one straight side that enters the iron core first, while the other straight side of the first coil of most windings enters the iron core last. The straight side that has not yet entered the iron core is always in a state of being “utilized” during the entire winding process. It will be subjected to necessary bending and deformation from time to time, and its mechanical properties will be damaged to varying degrees. In other words, the first coil suffers relatively greater process damage before the winding is formed, which means that the coil has certain quality defects.
Based on the common practice of winding connection, most manufacturers will use one end of the first coil as the connection point with the motor lead wire. That is, when the motor is running, the first coil is the power input end. According to the characteristic of the power supply voltage gradually decaying in the winding, the coil at the power input end has to withstand a relatively strong voltage impact, which naturally increases the quality risk of the coil.
Given the above characteristics, the first coil, especially when it is used as a power input, poses a significant quality risk. Therefore, during the motor winding manufacturing process, necessary measures should be taken to protect the first coil. Furthermore, during the wiring process, if conditions permit, the first coil used during the embedding process should be avoided as a power input terminal.
Regarding the protection of the first coil, some promising motor repair shops may selectively make some improvements, while motor manufacturers should inform Xianjue and take necessary quality assurance measures.
Post time: May-29-2026