How to wind a motor coil?

Winding a motor coil refers to the process of arranging and connecting insulated wire within a motor's stator or rotor slots to create the magnetic field necessary for operation. While physically winding a single coil involves wrapping wire around a form, the broader aspect of "winding a motor" often involves configuring multiple coils into interconnected windings.

Based on the provided information, let's focus on the configuration of coils within a motor winding, particularly for 3-phase motors.

Understanding Motor Windings

Motor windings are the heart of an electric motor, producing the magnetic forces that cause rotation. In many motors, especially common AC motors, these windings are placed in slots around the stator (the stationary part).

3-Phase Motor Winding Configuration

For 3-phase motors, the coil configuration is designed to create a rotating magnetic field when connected to a 3-phase power supply. The provided reference highlights key aspects of this setup:

• Coil-to-Slot Relationship: Mostly in 3 phase motors, the number of coils is often equal to the number of slots in the stator. This means each slot typically houses sides of one or more coils.
• Formation of Phase Windings: The individual coils are interconnected in a specific way to form three separate windings. These are referred to as the phase windings (Phase A, Phase B, Phase C, or R, Y, B).
• Coil Uniformity: Each coil included in these phase windings should be of the same size and shape. This ensures balanced magnetic properties across all phases.
• Coils Per Phase: The total number of coils in the motor is distributed evenly among the three phases. Therefore, the number of coils per phase is approximately 1/3 of the total coils in the stator.
• Connection Schemes: The three separate phase windings are typically connected externally in one of two main configurations:
  • Star (Wye) Connection: The start or end points of each of the three phase windings are connected together at a common neutral point, while the other ends are connected to the power supply.
  • Delta Connection: The end of each phase winding is connected to the beginning of the next phase winding, forming a closed triangular loop connected to the power supply.

This arrangement of coils into three distinct phase windings, uniform in size and shape, and connected in either star or delta, is fundamental to how a 3-phase motor operates, allowing it to generate a continuous rotating magnetic field.

To illustrate the concept of coils per phase:

Note: The physical process of winding involves selecting the correct wire gauge, insulation, and winding pattern (e.g., concentric, lap) based on the motor's design specifications, and carefully placing the wire loops into the stator slots. This is often done using specialized winding machines for consistency and efficiency.