Motor outdoors 1

[Feg]

Guys,

I am wondering if anyone can help me here, I supplied some motors,cast iron,B5 flanged, IP55. They were installed out doors which is fine but they were mounted in the vertical position. In general I would always recommend a rain canopy when used in the vertical position as there is a chance of water running down the shaft and causing problems in the windings. This motor has failed (see attached images)and i would like your comments as i really think they should have had rain canopies as these motor only have dust seals.

Thanks

Feg

 

[TurbineGen]

How long was that motor setting out before the picture was taken? There is significant corrosion on the stator and motor can which would indicate water ingression. I cannot determine the condition of the paper insulation or if the windings got excessively hot from the picture.

How was the motor run? Intermittently or continuously? How old is the motor?

------------------------------------------------------------------------
If it is broken, fix it. If it isn't broken, I'll soon fix that.

 

[Feg]

Hi TurbineGen,

The motor were supplied back last June, this motor was opened up a few days ago and the pictures were taken straight away. It is started by a soft start, and generally runs continuously but sometimes the operator can stop-start up to 10 - 20 time per hour which I think is a bit excessive. It is a 22kw drawing 21 amps normally but when a different product is added it will draw the FLC of 41 amps.
Thanks

Feg

 

[desertfox]

Hi FEG

IP55 is meant to have protection against jets of water from all directions therefore why would they need a rain canopy to prevent water getting into the windings, reading between the lines here what you are effectively saying is that without the rain canopy they don't meet IP55 or am I missing something.

regards

desertfox

 

[Feg]

Hi desertfox,

My understanding of IP55 is the enclosure provides protection from low pressure water jets.

But, and this is the point I am looking for help on, when the motor is in the vertical a rain canopy is required and i think this is because water can run down the shaft and or water resting on the NDE cover could get past the dust seal.

Feg

 

[desertfox]

hi FEG

I used this site:-

http://www.aquatext.com/tables/ip_ratings.htm

What it does say and I should have read more is that if water jets are from all directions then limited ingress is permitted.

desertfox

 

[edison123]

IP 55 or not, I advise my clients to use a light-weight canopy for all their outdoor motors. Have seen a few winding failures in these IP 55 motors due to water entry with corroded portions inside the body.

Many smart-alecs then question why all the transformers are not put under canopy. I tell them that trafos are static and unlike motors they don't have rotating parts. Any rotating component requires a running clearance, which is often sufficient to let the water in.