Regardless of customer or quality traceability requirements, the marking of the motor wiring system is necessary and critical!

Terminal markings
For single-phase motors, the wire marking is relatively simple. You only need to distinguish the head and tail. For three-phase motors, you need to use necessary markings to distinguish the heads and tails of different phases. For motors with outer delta connection, there are at least 6 wires, and for low-voltage high-power motors or multi-speed motors, the number of wires will be more. Some manufacturers use the color of the wires to distinguish different phases, and the head and tail are distinguished by sleeve labels; While many manufacturers use a single color wire, the different phases and heads and tails are distinguished by different colored sleeve labels, or sleeve labels. The colors are also the same color and are distinguished only by prescribed letters and numbers.

Regarding the requirements in this regard, the standard does not make mandatory provisions, as long as the motor production and manufacturing processes, especially the maintenance requirements during customer use, can be guaranteed. However, from a humanistic perspective, direct, clear, simple and fast identification is more conducive to process quality control and user use; it is recommended that motor manufacturers can improve in this aspect.

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Terminal identification control
In order to further ensure the identification of the motor manufacturing process and customer use process, line end marks are added to the connectors. This measure is also implemented by many manufacturers.

Terminal board wiring identification
The more common wiring boards for three-phase motors include 3-column and 6-column wiring boards. The 3-column wiring board is generally used for motor stators with inner star connection or inner delta connection, as well as for winding motor rotor wiring. The wiring board is also only the words "U, V, W" (used for the stator part) or "K, L, M" (used for the wound rotor part) are marked. For motors with external star connection and delta connection, they must be 6-post terminal board, and mark the three phases and head and tail marks at the appropriate position of each terminal post, namely "U1, U2, V1, U2, W1, W2". The wiring process should ensure that the terminal mark and the terminal board mark are connected consistently.

In actual use cases, there are always some problems with incomplete or inconsistent markings, which to customer maintenance difficulties or operational errors. From the perspective of manufacturers, they should learn to think from other people's perspective to ensure that every motor user can follow the necessary instructions. Correct operation of the identification information; in the production and manufacturing process, the completeness and consistency of the identification information are the quality performance that any motor should have, especially for motors with special requirements, such as: personalized outlet and steering that are different from standard motors and other requirements, a comprehensive evaluation of its wiring system identification should be carried out.