How to Reverse Contactor Wiring

For a single-phase circuit, a simple relay can be used to turn the circuit on and off. The relay uses a small voltage to control a switch designed to control the larger voltage of the single "hot" wire. For a three-phase circuit, there are three "hot wires." Turning this type of circuit on and off requires turning all three "hot" wires on or off simultaneously. The device that does this is called a contactor -- a relay designed to handle three-phase circuits and used extensively with three-phase motors. By making a few changes to the contactor wiring, you can reverse the direction of a three-phase motor.

Screwdriver

Instructions

- 1
  Shut off the power to the motor and contactor circuit at the main power panel. A motor has three hot wires typically labeled T1, T2 and T3. The power wires, or "hot" wires, that feed the contactor are usually labeled L1, L2 and L3.
- 2
  Locate the T1, T2, T3, L1, L2 and L3 wires for the contactor. A contactor is typically wired T1, T2 and T3 for the motor to T1, T2 and T3 for the contactor; then L1, L2 and L3 for the power source to L1, L2 and L3 for the contactor. To reverse the contactor wiring, change two of the wires on one side of the contactor.
- 3
  Use the screwdriver to disconnect L1 and L3. Reverse these two wires so that L1 connects to T3 and L3 connects to T1. This connection will reverse the motor direction once power is restored to the circuit.

How to Change a Photocell Disconnected From a Lamp Post

How to Hook up a Hanging Lamp

Electrical Repairs