The rule is simple: the capacitor is connected in series with the auxiliary winding, and this branch goes to the 220 V line (phase and neutral) in parallel with the main winding. The practical details are on the diagram inside the motor's terminal cover, and that diagram always takes priority.

The logic of the connection

  • The main winding is connected directly to the supply and carries the motor's real power.
  • The auxiliary winding is fed through the capacitor; the capacitor advances the current in this winding and lets the motor start.
  • In a dual-capacitor motor the run capacitor is permanently in circuit; the start capacitor is connected in parallel with it and comes in only during starting through a centrifugal switch or start relay.
  • The protective conductor (PE) must always be connected to the earth screw on the housing.

Safe working sequence

  1. Switch off the breaker and confirm that the line is dead.
  2. Before removing the old capacitor, photograph which terminal each lead goes to.
  3. Make sure the capacitor is discharged; a charged capacitor can give a shock even with the power off.
  4. Place the links and leads according to the diagram in the cover and tighten the terminal nuts.
  5. Close the cover, then switch on and check the direction of rotation.

To reverse the direction, the auxiliary winding leads are swapped relative to the main winding; how this is done is explained in the question on the capacitor and direction of rotation. We recommend having the connection made by a qualified electrician.

If you need a new motor, see the single-phase 220 V electric motor models and find current information in our article on single-phase motor prices. Send a photo of the terminal box on WhatsApp; we will check the wiring diagram together.