Motor windings

[Kuldipkenya]

We have a motor which drives a fan. It is mounted on top of a Tea Dryer.We have a problem that the motor fails after every six to eight months.Every time the windings on the drive end are burnt but the non drive is as good as new.
The bearings are ok, so are the bearing housings.The drive belts are all in line with the fan pulley.
Should we replace the motor? It is 7.5kw 4POLE MOTOR. The rating is IP44.

 

[jraef]

Is there a VFD running this drive?


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[itsmoked]

Is the motor in the air flow?

IP44.. Is this a TEFC motor?

Is this motor mounted drive shaft down or horizontal?

What is its typical usage schedule?

What is the typical ambient humidity?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Kuldipkenya]

Yes it is TEFC motor. Horizontal mounted.The motor is in air flow.It is used 15hours a day.About the ambient humidity i can only say that it is in a heavy rainfall area.

 

[edison123]

Every time the windings on the drive end are burnt but the non drive is as good as new.

What exactly you mean by this ? What is the motor current when running on load ?

 

[catserveng]

Go to the following website,

http://www.easa.com/

and click on Industry Resources, then find the article, Failures in Three Phase Winding. There are several pictures of various three phase winding failures that may help you in your diagnosis.

Hope that helps.

 

[7anoter4]

I think the motor is often overloaded and as I understood the container is heated [by coal or gas]. The ventilator [merely is a kind of compressor] is located in the container inner top side. Nevertheless the gear is outside located, the gear may be also hot.
IP44 is not actually TEFC [Totally Enclosed Fan Cooled] and the motor ventilator is
located on the non-driving side. So, even the motor cooling air passes through the driving side winding, still the air is cooling more the other end winding.
The weather, in the summer time, and the sunlight may also add some supplementary heating.
If you cannot lower the overload trip setting and if you cannot replace the motor for 10 hp-let's say-you still may enhance the motor cooling and avoid sunshine. This will help, in my opinion.

 

[Kuldipkenya]

Thanks every one.Will replace the motor.
Thanks

 

[itsmoked]

Replace it and put a sun shade on it.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[zlatkodo]

Most important is value of no load phase current and phase current with full load. I think you must check winding data. See:

http://www.youtube.com/watch?v=guPfSCPNiZI

Zlatkodo