Share optimal solutions, professional HVACR knowledge and industry news

How to Solve Fan Motor Issues?

Content Category

In your daily life, you will definitely come into contact with many home appliances (air conditioners, refrigerators, washing machines, range hoods, fans, etc.), and they all have fan motors to ensure normal operation. Then, inevitably the fan motor will encounter many problems and sometimes can’t use normally, what should we do? The following knowledge may give you some ideas so that you can solve the problem by yourself. See let’s read the article.

Why the Fan Motor Does Not Rotate?

1. Most people may encounter the following issue: the fan does not rotate. You can pull it with your hands or wait a long time before it slowly rotates by itself. After using the fan motor for a period of time, you will find that it won’t work even though you pull it with your hands.  The fan motor can’t rotate due to the excessive axial clearance of the shaft.

2. The starting capacitor of the fan becomes smaller. After discharging it, you will find the shaft can still run normally, but it is not enough to make the motor rotate.

3. Poor maintenance and long-term lack of lubricating oil. Must ensure the fan shaft has lubricating oil, otherwise the fan can’t be driven to rotate. You can turn off the power, then flip the fan blades. If you feel the fan motor is tight, basically there is lacking lubricating oil.

4. Wear and tear caused by long-term use. After a long time of use, the motor will wear out, and the shaft sleeve of the motor will be very worn. Method: Discharge the fan, then you will see the motor. Oil the fan motor, wait until the motor bearing is evenly covered with lubricant, then assemble the fan for testing.

Fan motor doesn’t rotate

How to Solve the Reversal of  Fan Motor?

1. A single-phase fan motor has two sets of coils, including a common terminal, a running terminal, and a starting terminal. The capacitor is connected between the running terminal and the starting terminal. When the power is connected between the common terminal and the running terminal, the motor rotates forward; when the power is connected between the common terminal and the starting terminal, the motor reverses. You can change the phase sequence of the power supply, if the three-phase fan motor reverses.

2. Reverse rotation caused by fan motor damage, you can replace the fan motor with a new one.

3. Improper installation of the blade causes the fan motor reversal, please re-install the blade correctly.

4. If you are not sure, had better ask the supplier or after-sales team of the fan motor manufacturer for help.

The Fan Does not Rotate Solutions

1. Pull the fan blade with your hands after turning off the power, if it turns stiff, means that the fan’s lubrication effect is not good. You should use some lubricant oil to lubricate the shaft, so that the motor can rotate blades correctly. After discharging the motor, if the axial clearance of the rotation shaft is too large,  you can adjust the clearance by adjusting the shim. disassembling the motor is easy, but be careful when installing it back, otherwise the motor will be damaged. When installing the motor, the rotor must be aligned with the bearing and installed firmly.

2. Replace the capacitor with the same parameter. The capacitance of the capacitor can also be larger than the original, but not more than 20% of the original capacitor.

Why Does the Fan Motor Smell Like Burning?

1. The coil is burnt out

Take the ordinary fan motor as an example. There is a resistance of one hundred to three hundred Ω (ohms) between any two of the 5 wires of the motor, especially the connection between the two ends of the capacitor. There must be resistance volume to measure any two of the 5 wires. If have no resistance, Then must replace the coil immediately.

2. The capacitor burns out

The capacitor is generally 1.5uF, sometimes it is broken but there is no suitable volume capacitor, you can use two or three large capacitors in series, such as 5uF capacitors, two in series is 2.5uF, and three in series is 1.7uF. But you must notice the capacitor should not be too large. If you have to increase the capacitor volume to rotate the fan motor, very likely the fan motor has a short circuit between the layers. In this case, you must replace it with a new one.

The video shows the burning of the fan motor

Common Faults Of The Fan Motor

1. The coil winding is short-circuited

When the fan motor has a local short circuit issue, the motor will make a buzzing sound, meanwhile the electric fan can not rotate.

2. Open circuit of the coil winding

When the fan motor has an open circuit fault, after the electric fan is energized, the fan has no response and the fan blades can not rotate. Use a multimeter to test the winding on and off, then you can judge the failure of the winding.
Note that when the fan has a motor winding failure, the general solution is to replace it with a new fan motor, or ask the after-sales team of supplier to repair, but the cost is generally greater than directly replacing a new motor.

3. Bearing lack of oil

When lubricant oil of the bearing is insufficient, the electric fan motor will difficultly rotate, accompanied by a buzzing sound.

Maintenance method: Disassemble the motor (taking care not to break the winding wire of the motor), inject a proper amount of lubricating oil or butter into the bearing of the motor, then gently rotate the shaft. When the bearing can rotate flexibly, restore the motor, and finally start the fan again.

How to Measure the Quality of An Electric Fan Motor?

1. Check whether the power cord is energized. If there is no power, then you need to replace the power cord.

2. Tighten the motor rotor shaft to see if it is active. If the activity is not smooth, then you need to add lubricating oil.

3. Use a multimeter to measure whether the timer and the gear switch are energized (some are equipped with a fuse), then measure whether the mainline of the motor and the gear line are connected.

4. Check the discoloration and burnout situation of the coil. If there is discoloration and burnout, you need to replace the motor or ask for after-sales service.

5. Check the capacitor. You can pull the fan blade when the fan is energized. If it can’t pull out, then the capacitor must be broken. You need to ask the supplier for help or buy the same model capacitor instead.

High-quality fan motor

Why the Fan Motor Has Smoke When It Runs?

When the fan runs for a long time, between the rotor and the bearing will produce coking materials, which hinders the normal operation of the rotor.

When the motor is running, the coking materials smoke due to the increasing temperature, then will cause the winding to burn.

Repairing a burned fan motor is a very high cost, so had better replace the broken fan motor with a new one.

Conclusion

When you know more knowledge about fan motors, it will be easier to solve the issues by yourself, which means everything is under your control, right?

So that is why we listed the above knowledge to help everyone, “sharing is the greatest virtue of mankind”.

Enjoy the knowledge learning.

Any comments?

Welcome leave a message or repost.

Facebook
Twitter
LinkedIn
Reddit
Print

Leave a Reply

About Our Company

China Speedway Group is a professional HVACR products’ manufacturer and wholesaler, we customize different HVACR products and spare parts, especially refrigeration products and parts. Such as air conditioning, refrigeration equipment, cold room solution, ice machine, dehumidifier, electric motor, heat exchanger,copper coil, etc.

As worked in HVACR field since 2010, we have more experiences can provide you unique products and solutions, also will supply life-span free charge of technical support. Warmly welcome inquiry us with your sample, drawing or design, our aim is making your idea come true and benefit you. 

What’s more, for our clients, we will source other products, verify the supplier, negotiate with them with free charge for you.

About Author

Picture of Vic Cheung
Vic Cheung

Hi, I'm Vic! Start working in HVACR field since 2008, our main products included: air conditioning, cold room refrigeration system, water chiller, ice machine, commercial dehydrator, dehumidifier, heat pump, electric motor, and all accessories. Since joined China Speedway Group in 2012, I worked in here more than 10 years, as the general manager of export department, we have established 50+ agent in different countries and areas.
As our experience and strong technical support, we can solve your issue once you have, and our chief engineer has worked in HVACR field since 1997. I am so proud of our knowlege is more and more popular not only for engineer, and for HVACR business new comer, DIY lovers. Hope you are enjoying our articles, if any question or comments just welcome to send me marketing at cn-beyond.com

All Posts

Contact Us

Just fill out your email address, phone and a brief description of your inquiry in this form. We will contact you within 24 hours.

Contact Us

Ready to Start Your Project Wth Us?

Partner with us to increase your brand reputation, get an impressive experience for your clients to remember you lifelong, and help you stand out in the competitive market !

Don’t Miss Out on the Best OEM Partner!

Ready to Work With Us?

Experience our difference and Take the first step toward a better future for your business!