Motor IP Ratings and Rain hoods

[ukgraduate]

Hi guys,

We are using IP66 motors on our site and in some instances we have motors mounted vertically outside. Do these motors require rainhodos over the fan? These will be installed where there is a lot of rain per year.

There are conflicting views in the office, some people say yes and some say no. I would like to get some other opinions.

Are rainhoods normally installed on lower rating IP motors? Should the IP rating of the motor not come into he rain hood over of the fan?

Please let me know your thoughts.


Regards

 

[hooverdale]

IP66 motors are dust tight and rain tight (protected against powerful water jets from any direction). So outdoor installation with cover or without cover will not going to be a problem.

Check the IP Code to see what IP rating are suitable for outdoor installation or simply ask your supplier to avoid any warranty issues.

 

[Skogsgurra]

I would use a rain hood. Especially if the motors do not run continuously. When the motor runs, it heats up and inside air migrates out. When the motor cools down, air is sucked in from outside and if there is water - it will be sucked in, too. You need watertight motors in some cases.

If the motors are running continuously, or if there is a heater built into the motor, you can skip the hood.

Gunnar Englund

http://www.gke.org

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Half full - Half empty? I don't mind. It's what in it that counts.

 

[ozmosis]

I guess it depends how long you want your motors to last. IP66 is not weatherproof, it is just protected against high pressure hoses for short periods of duration, not weeks of rain. I'd fit weather hoods too, for rain/snow/UV protection.

 

[ScottyUK]

High IP ratings sometimes work in reverse, as Gunnar has indicated. They 'breathe' damp air into the interior where it condenses and becomes trapped. The liquid level builds up until it becomes a problem. Personally I would suggest a standard IP55 motor with a heater is all that is required for outdoor duty. Even cooling tower motors - which is about as bad as it gets in terms of environmental conditions - are usually IP55 types.

 

[macmckim]

A simple solution regarding water building up inside the motor frame /endbracket - may the motor is shaft up or shaft down position is to install automatic breather/drains in the endbracket.
Depending on the endbracket design (internal webbing), typically four are used, 90 degrees apart. Also recommend using sealed bearings (LLB or 2RS) if motor is below 75KW. Space heaters are OK, but if water builds up in end-brackets and floods up towards the winding, eventually
either bearings fail (typically first to fail) or winding grounds out.

macmckim