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OT- What makes for a electric motor which can run out in the weather?

Trboatworks

Diamond
Joined
Oct 23, 2010
Location
Maryland- USA
I need to stand up a cyclone dust/chip collector outside of the shop.
I am thinking full enclosed small shed or just a partial cover like a roof over the top.
I see setups though where these are installed fully exposed.
What’s the story- will just any motor put up with a few years of running out in the weather or are special motor types needed for this?

The motor on this unit is a TEFC.
I am wanting to get this in service - the simplest setup is just post to bolt the unit to over a small deck for the chip drum and set a bit of roof over the motor.
Everything would have to put up with damp weather and the like..

I want this setup as simple as possible- no return air to shop, run a dolly up to grab the chip drum- just get the debris out of the shop and done...
 
I guess an explosion-proof motor would be one possibility. But I think a TEFC with protection to keep rain off it and out of the fan would be sufficient for years of service outdoors. You don't want water getting in the dust bin either.

Car washes have special motors that run in water spray, but that is probably overkill.

Larry
 
In my gravel pit wash screen motors typically last 20-30 years if not subjected to electrical or overload abuse. I used standard TEFC motors, pointed Marrettes up (very important) and had a small vent at bottom of junction box. Box must not be on top of motor but at side or bottom. When I finally sold out a few years ago one 7.5 hp motor had been in service since the 60's, on top of a wash screen, continuously sprayed by mist and splashing water. It only needed a couple bearing changes. FWIW the fan shroud and fan were removed by bouncing rocks about 20 years ago, but as we joked, it was water cooled so not an issue!

Clean power is one of the most important issues for electric motor life with under voltage quickly killing motors. I used v belt drives on small motors to limit ultimate loads allowing fuse to blow before motor. 25hp on up got an electronic soft start which could cut power quicker than a fuse or breaker during OL conditions. A Marrette came off inside a motor box during operation and it cut power so quickly the fuses remained intact.

Now I would use a soft start on any motor given how cheap they are.
 
Larry-
Yeah- I am wondering if I will have condensation in the cyclone mess up the works.
This is a bolted together unit but would be a nuisance to unbolt to clean.
 
As long as it runs long enough to build substantial heat in the windings it will drive out the condensation thus I was able to use a TEFC motor with near continuous water spray.
 
Lead I am a one man shop but the dust collector does get some run time if I have to plane a bunch of boards.
Some tools like the sanders or band saw short goes at it..
The unit will sit however for days with no run.

This is the time and money question – I’ve been throwing too much of both into a shop remodel.
Bolting this thing to a post out back would be great if it would run out there .
 
I do a lot of machining work for a local Poultry plant, Was engineer there before I retired. At the end of everyday all the machinery is high pressure washed with water mixed with detergent then High pressure rinsed with water and chlorine mixture. Next day before start-up they again washed with High Pressure water/chlorine. Most motor companies sell wash down motors and what is used in the production areas and last a long time.
 
Get you a large metal drum or plastic bucket that will cover the motor when cut in half. Cut in in half and leave enough to make hold down straps. Make some 1/2" or 3/4" holes in each end for sufficient airflow when pulled by the fan. If it is truly a TEFC, it should last forever.
 
Ok- I am headed to shop- I will sus out motor.
I have a bunch of big plastic solvent drums.
I like it- no damn roof framing/shingles- this is out of sight so rough and ready will serve..
 
IME key is drilling a drain hole in the lowest spot of the motor, if horizontal mounted bottom of both end bells. Better motor makes will come with plugged holes and you just remove the correct plugs. I have seen motors over 90% full of water on occasional use things that sat out side and just filled up with condensation - temp swings. A heat sinked motor excells at loseing heat the secound the sun is off it and in the humid uk they literally just fill up with condensation in under 12 months typically. Drill a hole and your golden. All the better if you run it often enough to keep it warm and dry!

Over here we have IP rateings regarding sealing but even then its only against water ingress, in a condensing enviroment, drainage is key. Sealing alone won't be good enough to get you there on a motor.
 
What orientation for the motor shaft? If shaft up or down water ingress through the bearings is an issue and needs to have shielding so water cannot get to the shaft.
 
I have two electric motors sitting outside on a concrete pad. One powers the lawn sprinkler pump, and the other powers the pump for the water system for the house. With them outisde in the Florida weather some five miles from the ocean, we have had no problems since the house was built three years ago.
 
One thing I am surprised at is no one talks about overload relays. Breakers and fuses are not intended to protect the motor, they are for the wires.

As far as motors are concerned, I have seen open drip proof motors used outside for years with no problems. The key is to keep crap out of the motor.

Tom

Edit:- If you are dealing with wood dust, best you get explosion proof motor and control unless you have some way to keep the dust out of the control. Is the control outside of the building?
 
....

As far as motors are concerned, I have seen open drip proof motors used outside for years with no problems. The key is to keep crap out of the motor.
...

Mostly that works fine.
No mention from the OP if he wants this to run 3 years or 50 years with no problem.
Unsure the explosion proof as the motor (hopefully) won't see the dust in the collector unit and has plenty of outside air.
Bob
 
Any open motor should not work well in the southeast US, the mud-dobber wasps would fill it up quick unless it is run quite often.
 
Here in PA the mud-dubbers will fill up anything they can get into, paper wasps too. Not sure what does it but it's similar to a mud-dubber in that it will fill screw holes too. Anything will ball bearings is not going to last long outside in weather that drops below the dew point. Bronze will last longer if water resistant grease is used. But those wash down motor will last the longest. However do not use voltage above 240VAC, 480VAC and water don't mix!!! When I was getting ready to retire they hired an Engineer sill in University at night. They gave him a project to design the new line, to save electrical expense he used 480VAC in production area. I tried to tell everyone there is no savings in halving amp. and doubling volts but they wanted him to be left alone and this guy would listen to anything I said, he knew everything! Lasted only a year, everything was changed back to 208 wye!
 
I know from personal experience a 3 phase open frame motor will run under water for a week a time. The motors were 15 horse 480 volt and would sometimes be 2 feet under (Most of the time not). I asked the motor rewinder why the first one lasted longer and he said that it was enclosed. I have since gone to an upright pump with a vertical spindle. The first vertical spindle pump died way too soon when a mud dobber nest let go when the water hit it, that sand blasted the windings. That was my only electrical failure all the others eventually died from bearing failures.
On the new pump I glued window screen over the openings to keep the critters out. The enclosed motor lasted 3 years the open frames lasted about 1 1/2 years if they did a fair amount of pumping when submerged.
The photo is the first vertical shaft that the mud dobbers took out. Beside sometimes being covered in water the center pivot passes over the pump also.

newpump.jpg
 
Of the hundreds of collectors I have wired over the years, mostly Donaldson Torrit units, standard equipment is a TEFC motor mounted vertical with the fan up, providing a slinger action during ice, rain, snow. They normally last a long time with the proper voltage supplied.

Bigger units like 100HP and above had a ground mounted blower with a TEFC horizontal mounting.

SAF Ω
 
Wow! I didn't think the motors were run when submerged! An option I have seen is to supply each motor with a cylinder of dry nitrogen with just enough pressure to keep water out.

Tom
 
If lubricated and run often the bearing will last quite a while outside, But if not condensate will destroy bearing especially ball bearings. When Hess Oil closed there refinery in N.J. they had a skeleton crew of men that would run motors and pumps periodically all of which are outside to stop the moisture from collecting and rusting the bearings. I mentioned in the forum in another topic of a K&T mill I purchased that was stored in a open building unheated. Machine was in excellent condition looking at the outside. All unpainted surfaces were heavy grease covered. Only issue it had was at onetime the cover was removed that held the speed changing dial and no one could figure out how to re-time it. They simply made speed labels and put them over the existing numbers. When I removed the cover to make an attempt to fix the problem I found every horizontal bearing rusted on the bottom. Condensate collected and puddled at the bottom. When I mentioned that to my Uncle that worked for Chevron near Hess he told me about Hess and the reason they had the skeleton crew.
If insulated properly 480VAC will be OK with wet conditions but something like wire nuts and EMT not rigid or sealtite will soon have electrical problems! Also to add to the problem at the poultry plant Chlorine was added to the water.
 








 
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