How To Connect A Starting Capacitor To A Single Phase Motor

4 min read Jun 26, 2024
How To Connect A Starting Capacitor To A Single Phase Motor

Connecting a Starting Capacitor to a Single Phase Motor: A Step-by-Step Guide


Single phase motors are widely used in various applications, including HVAC systems, refrigeration, and air conditioning. However, these motors require a starting capacitor to operate efficiently. A starting capacitor is a specialized capacitor designed to provide the necessary boost to start the motor. In this article, we will guide you through the process of connecting a starting capacitor to a single phase motor.

Understanding the Components

Before we dive into the connection process, let's understand the components involved:

  • Single Phase Motor: A single phase motor is a type of induction motor that uses a single phase power supply.
  • Starting Capacitor: A starting capacitor is a special type of capacitor designed to provide a high voltage and current to start the motor.

Connection Diagram

The following is a basic connection diagram for a single phase motor with a starting capacitor:

  |  Single   |
  |  Phase    |
  |  Motor     |
  | Starting  |
  | Capacitor |
  |  Main     |
  |  Supply   |
  |  (L1)     |

Connection Steps

Follow these steps to connect the starting capacitor to the single phase motor:

Step 1: Identify the Motor Terminals

Identify the motor terminals, usually marked as L1, L2, and Ground (GND). L1 is the main supply terminal, L2 is the auxiliary terminal, and GND is the ground terminal.

Step 2: Identify the Capacitor Terminals

Identify the starting capacitor terminals, usually marked as C1 and C2. C1 is the positive terminal, and C2 is the negative terminal.

Step 3: Connect the Capacitor to the Motor

Connect the capacitor to the motor as follows:

  • Connect the positive terminal (C1) of the capacitor to the auxiliary terminal (L2) of the motor.
  • Connect the negative terminal (C2) of the capacitor to the ground terminal (GND) of the motor.

Step 4: Connect the Main Supply

Connect the main supply (L1) to the main terminal (L1) of the motor.

Step 5: Check the Connections

Double-check all the connections to ensure they are secure and correct.

Important Safety Precautions

  • Always disconnect the power supply before starting the connection process.
  • Ensure the capacitor is rated for the motor's voltage and current.
  • Use proper wiring and insulation to prevent electrical shock or fire hazards.


Connecting a starting capacitor to a single phase motor is a relatively simple process. By following the steps outlined in this article, you can ensure a safe and efficient connection. Remember to always follow proper safety precautions and use the correct components to avoid any electrical hazards.