Motor Impeller Rotation

[nightfox1925]

I have a TEFC motor which is rated as "Bi-Directional"

If we decide to change the motor rotation direction by swapping A and C leads, do we need to mechanically change the cooling fan impeller to match the new direction?

Regards...

 

[edison123]

No. That's why it is stamped Bi-directional. The cooling fan will be of centrifugal type with straight blades, which works in the same way, in either direction.

 

[nightfox1925]

Thanks edison123, I also got a confirmation from OEM that there is no need to modify fan impeller position for bi-directional motors.

However, somebody went "howdy" at site and modified the impeller position before it was queried to us.

 

[edison123]

How exactly did they modify the impeller position ? If they turned the fan along with the hub 180 degrees horizontally, then the suction and discharge positions change leading to poor performance. If then turned only the impeller wheel, then it wouldn't change anything (provided it is a straight leaf centrifugal fan)

 

[waross]

I'm trying to think of a type of bidirectional motor an that can be changed without worse performance. I hope the balance was not upset.

Bill
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