Home › Electric Motors › Single Phase Electric Motors Guide

Single Phase Electric Motors - UK Stock & Technical Guide

Single Phase Motors UK | Buy 230V Motors | FREE Next Day Delivery

Capacitor Start/Capacitor Run

Capacitor Start/Capacitor Run

High starting torque for demanding applications. Ideal for car lifts, compressors, conveyors, woodworking machinery, and gearboxes. 0.18kW (0.25hp) to 3.7kW (5hp).

Permanent Capacitor Motor

Permanent Capacitor Motor

Low starting torque for applications such as pumps, fans, blowers, and ventilation. 0.09kW (0.12hp) to 3.0kW (4hp).

110V Single Phase Motor

110V Single Phase Motor

Safe for construction sites and portable equipment where a 110V is mandatory. Ideal for workshops, site tools, and temporary installations.

NEED HELP CHOOSING A SINGLE PHASE MOTOR?

Use our quick Motor Selection Wizard to get the right motor first time

Find My Motor

What is a Single Phase Motor?

A single phase electric motor operates on a single alternating current (AC) waveform, making it ideal for applications where a standard UK 230V domestic or light industrial power supply is available. Unlike three phase motors which require a three-phase supply (typically 400V), single phase motors connect directly to a standard 13A socket or dedicated single phase circuit.

Single phase motors are the practical choice for workshops, small businesses, farms, and domestic applications where three phase power isn't available or cost-effective to install. They power everything from compressors and car lifts to pumps, fans, and woodworking machinery such as lathes, pillar drives and circular saws.

At MM Engineering, we stock a comprehensive range of single phase motors from 0.09kW (0.12hp) to 3.7kW (5hp) in both 230V and 110V configurations. Our motors are to the new IE2 high efficiency, have metal terminal boxes to house the capacitors, manufactured to IEC standards, and supplied with a 12-month warranty. One additional benefit our motors have over others is they have a built in thermal protection system. With same day despatch, FREE next day delivery on UK mainland orders and expert technical support, we make buying the right single phase motor simple.

Single Phase Motor Types Compared

Choosing the right type of single phase motor depends on your starting torque requirements and application.

Capacitor Start/Capacitor Run

  • Starting Torque - High (1.8 - 2.5 times the rated torque)
  • Best For - Heavy starting loads
  • Voltage - 230V
  • Applications - Compressors, Car lifts, Conveyors, Gearboxes
  • Internal set up - Separate Start & Run Capacitor + Centrifugal switch
  • Power Range - 0.18kW (0.25hp) - 3.7kW (5hp)

    • View Catalogue

    Permanent Capacitor

  • Starting Torque - Low (0.3 - 0.7 times the rated torque)
  • Best For - Low starting loads
  • Voltage - 230V
  • Applications - Fans, Blowers & Pumps
  • Internal set up - Single start capacitor permanently connected
  • Power Range - 0.18kW (0.25hp) - 3.0kW (4hp)

    • View Catalogue

    110V Site Motors

  • Starting Torque - Medium
  • Best For - Construction sites where safety is critical
  • Voltage - 110V
  • Applications - Workshop tools (Circular Saws, Pillar Drills)
  • Internal set up - Two capacitors (Start & Run) + Centrifugal switch
  • Power Range - 0.37kW (0.5hp) - 2.2kW (3hp)

    • View Catalogue

    Capacitor Start/Capacitor Run Single Phase Motors

    Capacitor start/capacitor run motors (also called CSCR or two-value capacitor motors) are designed with two capacitors, which allow them to deliver the highest starting torque of any single phase motor type - typically 1.8-2.5 times the rated torque. This makes them essential for applications with high inertia loads or where the motor must start under load e.g. Car Lift, Compressors or Conveyor.

    - How They Work These motors use two capacitors: a large start capacitor and a smaller run capacitor. At startup, both capacitors are in circuit to create a strong phase shift that produces high starting torque. Once the motor reaches approximately 75% of full speed, a centrifugal switch disconnects the start capacitor, leaving only the run capacitor in circuit for efficient continuous operation.

    - Ideal Applications

    • Car lifts and vehicle hoists
    • Air compressors and refrigeration compressors
    • Conveyors and material handling
    • Woodworking machinery (saws, planers, thicknessers)
    • Gearbox-driven equipment
    • Crushers and grinders
    • Any application with high starting loads

    - Our Range We stock capacitor start/capacitor run motors from 0.18kW (0.25hp) to 3.7kW (5hp) in 2-pole (3000rpm) and 4-pole (1500rpm) configurations. All motors feature high-quality aluminium construction, NSK bearings, IE2 design, complete with Thermal reset switches for added protection and multi-mount design.

    Our most popular Capacitor Start/Capacitor Run Single Phase Motors

    IE2 Efficiency
    Amtecs 0.12kW (0.16HP) Three Phase Motor 4-Pole (1500 rpm) 63 Frame
    View Details

    Amtecs 0.12kW (0.16HP) Three Phase Motor 4-Pole (1500 rpm) 63 Frame

    amtecs
    IN STOCK

    Amtecs 0.12kW (0.16HP) Three Phase Motor 4-Pole (1500 rpm) 63 Frame
    £105.01Inc VAT £87.51 Ex VAT
    View Details
    In Stock
    Out Of Stock

    Delivery:

    In Stock
    Out Of Stock

    Delivery:

    In Stock
    Out Of Stock

    Delivery:

    In Stock
    Out Of Stock

    Delivery:

    In Stock
    Out Of Stock

    Delivery:

    In Stock
    Out Of Stock

    Delivery:

    Permanent Capacitor Single Phase Motors

    Permanent capacitor motors (also called capacitor run or PSC motors) offer reliable, maintenance-free operation for applications requiring low starting torque. With no centrifugal switch to wear out and only one single capacitor, these motors are simpler, quieter, and longer-lasting than capacitor start/run types allowing you to switch them more on/off frequently.

    -How They Work A single capacitor remains permanently connected in the motor start winding, providing continuous phase shift. This eliminates the mechanical complexity of a centrifugal switch but limits starting torque to approximately 0.3-0.7 times the rated torque. Once running, permanent capacitor motors are reliable but less efficient than other AC Electric motors.

    - Ideal Applications

    • Pumps (water, heating, circulation)
    • Fans and blowers
    • Ventilation systems
    • HVAC equipment
    • Agricultural fans
    • Low-inertia loads
    • Equipment with no starting load

    -Our Range: We stock permanent capacitor motors from 0.09kW (0.12hp) to 3.0kW (4hp). These motors are perfect for applications where the load starts unloaded (like pumps and fans) and smooth, quiet operation is important.

    Our most popular Permanent Capacitor Single Phase Motors

    IE2 Efficiency
    Amtecs 0.12kW (0.16HP) Three Phase Motor 4-Pole (1500 rpm) 63 Frame
    View Details

    Amtecs 0.12kW (0.16HP) Three Phase Motor 4-Pole (1500 rpm) 63 Frame

    amtecs
    IN STOCK

    Amtecs 0.12kW (0.16HP) Three Phase Motor 4-Pole (1500 rpm) 63 Frame
    £105.01Inc VAT £87.51 Ex VAT
    View Details
    In Stock
    Out Of Stock

    Delivery:

    In Stock
    Out Of Stock

    Delivery:

    In Stock
    Out Of Stock

    Delivery:

    In Stock
    Out Of Stock

    Delivery:

    In Stock
    Out Of Stock

    Delivery:

    In Stock
    Out Of Stock

    Delivery:

    Single Phase Motor Speed (RPM) Ratings

    Our single phase motors are available in various speeds, ranging from 1000RPM to 3000RPM, covering virtually all domestic, commercial and light industrial applications.

    Speed Options

    Single phase motors are available in three standard speeds:

    • 2-Pole (3000 RPM) - Higher speed, suitable for direct-drive applications like circular saws, pumps, and machinery requiring high rotational speed but have lower torque than a 1500rpm.
    • 4-Pole (1500 RPM) - Lower speed with higher torque, ideal for car lifts, gearbox-driven equipment, conveyors, and applications requiring more turning force.
    • 6-Pole (1000RPM) - Some applications also use 6-pole (1000 RPM) motors for very high torque requirements.

    Single Phase Motor Power Ratings (kW)

    Our single phase motors are available in various powers, ranging from 0.09kW (0.12hp) to 3.7kW (5hp), covering virtually all domestic, commercial and light industrial applications.

    • Power(KW) Power(HP) Typical Applications
    • 0.09-0.18 0.12-0.25 Small fans, pumps,polishing machine.
    • 0.25 - 0.55 0.33 - 0.75 Ventilation fans/blowers, pillar-drills, lathes with clutch systems.
    • 0.75 - 1.5 1.0 - 2.0 Pumps, circular saws, small machinery.
    • 2.2 - 3.7 3.0 - 5.0 150ltr+ Air compressors, car lifts, log splitters, heavy machinery, industrial equipment.

    Single Phase Motor Frame Sizes Explained

    Electric motors come in various frame sizes which determines the physical dimensions of the motor, including the mounting hole positions, shaft height, shaft diameter, length and keyway details. It is essential to match the frame size when replacing an existing motor.

    Common Frame Sizes

    • Frame Shaft Height Typical kW Range
    • 56 56 mm 0.09kW (0.12hp) - 0.12kW (0.16hp)
    • 63 63 mm 0.12kW (0.16hp) - 0.18kW (0.25hp)
    • 71 71 mm 0.25kW (0.33hp) - 0.55kW (0.75hp)
    • 80 80 mm 0.55kW (0.75hp) - 1.1kW (1.5hp)
    • 90 90 mm 1.1kW (1.5hp) - 2.2kW (3hp)
    • 100 100 mm 2.2kW (3hp) - 3.0kW (4.0hp)
    • 112 112 mm 3.7kW (5hp) - 4.0kW (5hp)

    Single Phase Motor Mounting Options

    All our single phase motors feature multi-mount design with removable feet, allowing flexible installation. Standard mounting options include:

    B3 (Foot mounted)

    The most common configuration, where the feet are bolted to a base/mounting plate.

    B5 (D Flange mounted)

    Large flange for mounting direct to equipment. No feet required.

    B14 or B14S (Small C Face mounted)

    Smaller face flange for compact installation with drilled and tapped holes.

    B14L (Large C Face mounted)

    Larger face flange for compact installation with drilled and tapped holes.

    B34S (Foot & Small C Face mounted)

    A combination of a foot mount and a small face mount for a secure fit with maximum flexibility.

    B34L (Foot & Large C Face mounted)

    A combination of a foot mount and a large face mount for a secure fit with maximum flexibility.

    B35 (Foot & D Flange mounted)

    Combination mounting with large flange providing both stability on the ground and a direct flange coupling to the driven equipment.

    V1 (Vertical Flange mounted with Rain canopy)

    Large flange for direct mounting in a vertical position to equipment. No feet required with added protective rain canopy that shields the top of the motor from water ingress, dirt, and debris.

    How to wire a Single Phase Motor

    Single phase motors have a terminal box with clearly marked connections. Typically: L (Live), N (Neutral), and E (Earth). The capacitor(s) are usually internally wired. Below is our typical wiring diagrams for a Capacitor Start/Capacitor Run and Permanent Capacitor motor and shows the how to wire the motor for clockwise and anti-clockwise rotation.

    Single Phase Motor Applications

    Single phase motors power equipment across numerous industries and applications:

    Agriculture & Farming

    • Grain augers and conveyors • Feed mixers • Barn ventilation fans
    • Water pumps • Milking pumps

    Woodworking & Workshops

    • Table saws and band saws • Planers and thicknessers

    • Dust extraction • Pillar drills • Lathes

    HVAC & Ventilation

    HVAC & Ventilation • Extractor fans • Air handling units

    Pumps & Water Systems

    • Borehole pumps • Pressure boosters • Swimming pool pumps

    • Pond pumps • Heating circulation pumps

    How to Select the Right Single Phase Motor

    Selecting the right single phase motor for your application requires matching several key specifications:

    • Frame Shaft Height Typical kW Range
    • 56 56 mm 0.09kW (0.12hp) - 0.12kW (0.16hp)
    • 63 63 mm 0.12kW (0.16hp) - 0.18kW (0.25hp)
    • 71 71 mm 0.25kW (0.33hp) - 0.55kW (0.75hp)
    • 56 56 mm 0.09kW (0.12hp) - 0.12kW (0.16hp)

    Single Phase vs. Three Phase Electric Motors: Quick Comparison

    Electric motors come in various frame sizes which determines the physical dimensions of the motor, including the mounting hole positions, shaft height, shaft diameter, length and keyway details. It is essential to match the frame size when replacing an existing motor.

    • Feature Single Phase Motor 230V Three Phase Motor 400V
    • Voltage (UK) 230V/240V 400V
    • Wiring Connections Live + Neutral (+ Earth) L1 + L2 + L3 (+ Earth)
    • Starting Method Capacitors + Centrifugal Switch Self-starting
    • Max Power Limit 3.7KW (5HP) Almost Unlimited (up to High Voltage)
    • Efficiency Standard - IE1 & IE2 High Efficiency (IE3/IE4/IE5)
    • Starting Torque Medium High
    • Full Load Torque Medium High
    • Variable Speed Control Not suitable for speed control Suitable for Speed control
    • Cost Higher Lower
    • Typical Use Home, Domestic, Small workshops Factories, Large Industrial/Manufacturing sites

    Single Phase vs. Three Phase Electric Motors: Real World Example (2.2kW)

    See below the actual difference between a 2.2kW single phase motor vs a 2.2kW three phase motor

    • Frame Shaft Height Typical kW Range
    • Voltage (UK) 230V/240V 400V
    • Power 2.2kW (3hp) 2.2kW (3hp)
    • Speed (RPM) Approx. 2800rpm Approx. 2800rpm
    • Frame Size 90L (90mm shaft height) 90L (90mm shaft height)
    • Wiring Connections Live + Neutral (+ Earth) L1 + L2 + L3 (+ Earth)
    • Efficiency IE2 – 83.2% IE3 – 85.9%
    • Starting Method 2 x Capacitors + Centrifugal Switch DOL Starting
    • Max number of start/stops 4-6 per hour 10 per hour
    • Efficiency IE2 – 83.2% IE3 – 85.9%
    • Starting Torque 16.79Nm 18.74Nm
    • Full Load Torque 7.3Nm 7.21Nm
    • Full Load Current 11.7A 4.35A
    • Cost £198.10 + VAT £160.56 + VAT
    • Availability In stock - FREE delivery to UK In stock - FREE delivery to UK

    Frequently asked questions
    What is a single phase electric motor?

    A single phase motor operates from a standard 230V single phase mains power supply.
    Where are single phase motors used?

    Single phase motors are commonly used in small pumps, fans, compressors, conveyors, car lifts, and workshop machinery such as pillar drills, circular saws, and bandsaws.
    What power range do single phase motors cover?

    We typically supply single phase motors ranging from 0.09kW up to approximately 3.7kW.
    What is the difference between capacitor start and capacitor run motors?

    Capacitor Start / Capacitor Run motors provide high starting torque, typically between 1.8 to 2.5 times the rated torque.

    Permanent Capacitor motors offer lower starting torque, generally between 0.3 to 0.7 times the rated torque.
    Can a single phase motor replace a three phase motor?

    Yes, for lower power applications (typically under 3kW), a single phase motor can replace a three phase motor when matched correctly for kW, torque, speed, and frame size.
    What speeds are available for single phase motors?

    Common motor speeds are:

    • 2 Pole ≈ 3000 RPM
    • 4 Pole ≈ 1500 RPM
      (at 50Hz supply frequency)
    Is a 110V version available for this single phase motor?

    Most of our single phase motors are 230V as standard. Please contact us if you require a 110V or dual-voltage option.
    Are single phase motors suitable for continuous duty?

    Yes, provided the motor is correctly sized and rated for S1 continuous duty operation.
    Can I use a speed controller with a single phase motor?

    No, we generally do not recommend using a speed controller with a standard single phase motor.
    Do you stock B3, B5, and B14 single phase motor mountings?

    Yes, we supply foot mounted, flange mounted, and face mounted single phase motors in common frame sizes. We also offer special B5R and B14L face plates. In addition, our workshop can manufacture custom mounting plates to suit specific requirements.