The reasons Why the Motor Overheats

Mar. 11, 2024


There are many reasons for the overheating of the motor. The power supply, the motor itself, the load, the working environment and ventilation and heat dissipation conditions can all cause the motor to overheat.


●Power Quality

(1) The power supply voltage is higher than the specified range (+10%), causing the core magnetic flux density to be too large, increasing iron loss and overheating; it also increases the excitation current, causing the winding temperature to increase.

(2) The power supply voltage is too low (-5%). When the load remains unchanged, the three-phase winding current increases and overheats.

(3) The three-phase power supply is missing a phase, and the motor is running out of phase and overheating.

(4) The three-phase voltage imbalance exceeds the specification (5%), causing the three-phase power supply to be unbalanced and the motor to generate additional heat.

(5) The power frequency is too low, causing the motor speed to decrease and the output to be insufficient. However, the load remains unchanged, the winding current increases, and the motor overheats.


●The motor itself

(1) If the △ shape is mistakenly connected to a Y shape or the Y shape is connected to a △ shape, the motor winding will overheat.

(2) The winding is short-circuited between phases or turns or grounded, causing the winding current to increase and the three-phase current to be unbalanced.

(3) Some branches in the parallel branches of windings are disconnected, resulting in unbalanced three-phase current, and the unbroken branch windings are overloaded and heated.

(4) The stator and rotor rub against each other and generate heat.

(5) The squirrel cage rotor guide bar is broken, or the wire-wound rotor winding is disconnected. The motor output is insufficient and generates heat.

(6) The motor bearings are overheated.

 The reasons Why the Motor Overheats


(1) The motor is overloaded for a long time.

(2) The motor starts too frequently and the starting time is too long.

(3) The towed mechanical failure causes the motor output to increase, or it becomes stuck and does not rotate.


●Environment and ventilation and heat dissipation

(1) The ambient temperature is higher than 35°C and the inlet air is overheated.

(2) There is too much dust inside the machine, which is not conducive to heat dissipation.

(3) The windshield or internal windshield is not installed and the air path is not smooth.

(4) The fan is damaged, not installed or installed backwards.

(5) There are too many heat sink defects in the enclosed motor housing, and the air duct of the protective motor is blocked.

We,Germana Tianjin Industrial Group is a leading supplier of high quality & efficiency electric motors in China for more than 35 years.Our sales team and technical team are willing to provide the best service for you. We'll be happy to answer any questions about electric motors. If you have any requirements, please feel free to contact us. Hope to hear from you soon.

How many types of insulating varnishes are used on a motor? The Advantages of Electric Motors Manufactured in China
Positioning us as the foremost exporter of electric motors in China with a consistent track record of high export volumes.
View More

Products Categories

Do You Need Our Help?

The technicians are trained and thoughtful to provide perfect technical consultation and after-sales service.

Contact Us


+86 15210826628



+86 022 8383 0415



Henghua Apartment, Minhou Road, Hexi District, Tianjin

Copyright © Germana Tianjin Industrial Group All Rights Reserved | Sitemap