Motor Run Capacitor Wiring Diagram: Everything You Need to Know

Motor run capacitors are an essential component of electrical systems that use motors. They provide the necessary power to start and run the motor, and without them, the motor will not function. In this article, we will discuss the wiring diagram of motor run capacitors in detail. We will cover the different types of capacitors, their functions, and how to wire them correctly. Let’s get started!

What is a Motor Run Capacitor?

A motor run capacitor is an electrical component that is used to provide the necessary energy to start and run an AC induction motor. It works by creating a phase shift between the start winding and the run winding of the motor. This phase shift allows the motor to start and run smoothly.

Motor run capacitors are also used to improve the efficiency of the motor by correcting the power factor. The power factor is a measure of how efficiently the motor uses the electrical power that is supplied to it. A low power factor indicates that the motor is not using the power efficiently, and a motor run capacitor can help to correct this.

Types of Motor Run Capacitors

There are two main types of motor run capacitors: electrolytic capacitors and film capacitors.

Electrolytic Capacitors

Electrolytic capacitors are the most common type of motor run capacitor. They are made of two metal plates separated by a thin layer of electrolyte. They are typically larger in size than film capacitors and are not as reliable due to their tendency to dry out over time.

Film Capacitors

Film capacitors are made of two thin layers of plastic film with a metal foil sandwiched between them. They are more reliable than electrolytic capacitors and do not tend to dry out over time. They are also smaller in size than electrolytic capacitors.

How to Wire a Motor Run Capacitor

Wiring a motor run capacitor is a fairly simple process, but it is important to do it correctly to ensure that the capacitor functions properly and safely. Here is a step-by-step guide:

Step 1: Turn off the Power

Before you begin wiring the motor run capacitor, make sure that the power to the motor is turned off. This is an essential safety precaution that should never be skipped.

Step 2: Identify the Capacitor Terminals

Look closely at the capacitor and locate the terminals. There should be two terminals labeled “HERM” and “FAN”. The HERM terminal is for the compressor, while the FAN terminal is for the fan motor.

Step 3: Connect the Power Supply

Connect the power supply to the HERM and COM terminals on the capacitor. The COM terminal is the common terminal and is usually located between the HERM and FAN terminals.

Step 4: Connect the Compressor Motor

Connect the compressor motor to the HERM and COM terminals on the capacitor.

Step 5: Connect the Fan Motor

Connect the fan motor to the FAN and COM terminals on the capacitor.

Step 6: Test the Capacitor

Once you have wired the motor run capacitor, you should test it to make sure that it is functioning properly. You can do this by using a multimeter to check the capacitance of the capacitor. If the capacitance is within the specified range, then the capacitor is functioning correctly.

FAQs

Q: What is the function of a motor run capacitor?

A: A motor run capacitor provides the necessary energy to start and run an AC induction motor by creating a phase shift between the start winding and the run winding of the motor. It also helps to improve the efficiency of the motor by correcting the power factor.

Q: What are the different types of motor run capacitors?

A: The two main types of motor run capacitors are electrolytic capacitors and film capacitors.

Q: How do you wire a motor run capacitor?

A: Wiring a motor run capacitor is a fairly simple process. You need to turn off the power, identify the capacitor terminals, connect the power supply, connect the compressor motor, connect the fan motor, and test the capacitor.

Q: What happens if a motor run capacitor fails?

A: If a motor run capacitor fails, the motor will not function properly. It may not start at all, or it may start and run for a short time before stopping.

Q: Can you replace a motor run capacitor?

A: Yes, you can replace a motor run capacitor. It is a relatively simple process, but it is important to make sure that the replacement capacitor has the same specifications as the original capacitor.

Conclusion

In conclusion, motor run capacitors are essential components of electrical systems that use motors. They provide the necessary energy to start and run the motor, and they also help to improve the efficiency of the motor. Wiring a motor run capacitor is a fairly simple process, but it is important to do it correctly to ensure that the capacitor functions properly and safely. By following the steps outlined in this article, you can wire a motor run capacitor with confidence and ensure that your motor functions correctly.