Hot line reactor? 2

[sky2020]

I have a 480V motor fed by 3% line reactors. The reactors are extremely hot. The cable length is 300 feet. Three different installations and the same problem but the motors are Europeans (Finland). Changed the pwm drive switching frequency to a minimum but no solutions. Any suggestions what can be the cause for the overheat?

 

[dpc]

Undersized reactors?

 

[itsmoked]

Check the expected motor current against the actual motor current. You will need to read the actual from the drives.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[jraef]

How hot is hot? Did you measure it or are you just going by "feel"? Most reactors are designed with insulation rated for 180C rise over a 40C ambient, so 220C max. Your reactor could be at 100C and be fine. The industry standard for "too hot to touch" is 60C, so there is a LOT of room between what we perceive as hot and what is actually bad for the equipment.

Also, you say "line reactor" in the title, then discuss motor lead length. On the motor side it is a Load Reactor. On the Line side, anything you do in the VFD settings is totally irrelevant. But the reason I bring it up is because if you purchased a "Line Reactor" for a specific motor HP, then mounted it on the LOAD side, that's a problem. Load Current on a VFD is higher than Line Current, because of the corrected Power Factor, so Line Reactors are sized differently than Load Reactors. A Line Reactor is going to be smaller, usually too small to be used on the Load side.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[davidbeach]

And if was installed as a load reactor the VFD is probably wondering what the heck is wrong with the motor.