The basic difference is the supply: a single-phase motor runs from a 220 V phase-neutral line and, because it cannot create a rotating magnetic field by itself, it needs an auxiliary winding and a capacitor; a three-phase motor starts without any extra device thanks to the rotating field produced by the time shift between three phases.

Differences you notice in practice

  • Current: For the same shaft power a single-phase motor draws noticeably more current from the line; cable cross-section and fuse grow accordingly.
  • Starting: A three-phase motor naturally has a high starting torque. In a single-phase motor starting strength depends on the capacitor arrangement; loaded starts such as compressors need a dual-capacitor type.
  • Smooth running: Torque in a single-phase motor pulsates every cycle, which shows up as slight vibration and extra heating.
  • Number of parts: The capacitor and, if fitted, the centrifugal switch are extra parts that age over time; a three-phase motor has no such parts.
  • Power range: At HEM Motor the single-phase 220 V series covers 0.18–5.5 kW, the three-phase asynchronous series 0.25–355 kW.
  • Speed control: Our three-phase series are suitable for speed control with a frequency converter; this route is generally not recommended for capacitor-run single-phase motors.

Which one to choose?

If the building has only 220 V and the power does not exceed a few kilowatts, a single-phase motor is the practical solution: domestic booster pumps, small compressors, garden and farm machines belong to this group. If a three-phase line is available, a three-phase motor does the same job with lower current and a simpler design. A detailed comparison is in our article on three-phase and single-phase motor types.

You can review single-phase models on the single-phase 220 V electric motor page and three-phase options in the three-phase electric motors category. If you are not sure which one suits your machine, send a photo of the old motor's nameplate on WhatsApp; we will determine the right model together based on supply, power and speed.