June 30, 2022
  • 3 phase motors use coils of wire to create a rotating magnetic field
  • 3 phase motors come in two types: Wye and Delta
  • 3 phase motors can be wired for high or low voltage
  • The leads for the coils are numbered 1-9, and follow a specific numbering convention
  • 3 phase motors can be wired in one of four ways: high or low voltage Wye, or high or low voltage Delta.

There are many different types of 3 phase motors, each with their own unique wiring diagram. In this article, we will discuss the basics of 3 phase motor wiring and provide some examples of how to wire them up. We will also cover some common problems that can occur during the wiring process, and provide tips for troubleshooting. So if you’re looking to install a 3 phase motor in your home or business, read on!

Three-phase motors are more efficient than single-phase motors and are used in applications that require more than 7.5 horsepower on a regular basis. Although the National Electric Code does not require specific conductor colors for three-phase current, it is commonplace to employ black, red, and blue wires to distinguish lines L1, L2, and L3.

Each line’s voltage cycle follows that of the preceding one by 120 degrees, with L2 reaching its maximum voltage after L1 and L3 reaching its maximum voltage after L2. The Wye and Delta wiring methods are used for three-phase motors in two ways. These instructions cover a dual-voltage, three-phase motor, which is the most frequent type.

  • 3 phase motors must be wired to a 3 phase supply
  • The nameplate on the motor will specify the motor voltages and may give specific wiring information
  • Many motors can be wired for a high and low voltage
  • Connect all wiring connections with wire nuts of the correct size for the conductors being used
  • If there is a neutral wire in the conduit or cable supplying the motor, it is unused for 3 phase wiring; cap it with a wire nut
  • To reverse motor rotation, swap any two line connections

3 Phase Motor Connection Diagram

wye and delta diagram

Low-voltage Wye

low-voltage wye

High-voltage Wye

high-voltage wye

Low-voltage Delta

Low-voltage Delta

High Voltage Delta

High Voltage Delta