A SIMPLE ILLUSTRATED GUIDE TO ELECTRIC MOTORS

FAQS about How to match capacitors with household motors

What types of motors use capacitors?

Here are some common motor types that use capacitors: 1. Single-Phase Induction Motors: Single-phase induction motors, commonly found in household appliances like refrigerators and air conditioners, often use start and run capacitors to provide the necessary phase shift for smooth starting and running. 2.

How to choose a capacitor for a motor?

Remember to choose a capactor whose voltage rating is at least equal to the rated voltage of the motor. It's perfectly fine to use a capacitor whose voltage rating is greater than the motor's voltage. For example if your motor runs at 220V your capacitor's voltage rating must be 220V or larger. A 330V rated capacitor is fine.

What is a motor capacitor?

You'll see that motor capacitors are characterized by at least five properties: measured in uF or microfarads, the amount of electrical charge stored in the capacitor and released when needed either to start the motor spinning (a start capacitor) or to help keep it spinning under load (a run capacitor).

Can a motor have a start capacitor?

A motor can have a start capacitor, run capacitor, or a combination of both. A start capacitor (figure 5) is connected to the motor windings through a centrifugal switch. It is used to increase motor starting torque and allow an electric motor to be cycled on and off rapidly (intermittent or brief use).

What is a run capacitor in a motor?

A run capacitor (figure 9) is used in single-phase motors to maintain a running torque on an auxiliary coil while the motor is loaded. These capacitors are considered continuous duty while the motor is powered and will remain in the circuit while the start capacitor drops out. Not all single-phase motors have run capacitors.

Why do motors need a capacitor?

To improve the motor’s performance: A capacitor can reduce the current lag in a motor, which makes the motor more efficient and increases its running torque. In other words, a capacitor helps a motor to start and run better.