# commercial kitchen exhaust



## TimPa (Jan 26, 2010)

local bar has a grease hood with a sidemount exhaust fan. I replaced the motor several years ago with original specs: 1/2hp split phase fr 56cz, odp. needs replaced again, just growling and turning slow with full voltage (110vac) applied. just wondering if this thing should have a tefc or even explosion proof? or a capacitor start? can anyone familiar with motor applications steer me? thanks


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## Fault Current (Jan 22, 2014)

Since fan motors don't need much starting torque you really don't need much more than a split phase. No need for capacitor start. If the motor is overloaded it will fail regardless. Put a bigger motor in like a 56 frame 3/4 horse motor.

TEFC or explosion proof have nothing to do with the issue. ODP is just fine. I'm assuming this motor is located indoors.

Question, is the motor actually in the airstream? It should be outside the duct. Just asking.


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## woodchuck2 (Feb 27, 2008)

Sounds like the fumes of the kitchen are getting into the fan itself leading to its failure. I would look into a sealed motor or another fan design that will take the motor out of the exhaust path.


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## TimPa (Jan 26, 2010)

fan motor is actually located outside. the motor is direct drive and has a domed baffle to direct the airstream around the motor. all help is appreciated.


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## woodchuck2 (Feb 27, 2008)

Are these motors sealed or vented? This post will contradict what i posted above but i have seen motors fail prematurely from heat. Normally in a kitchen grease gets into everything and why i would recommend a sealed motor. But, now we have to look at how hot this motor is getting too. If it is a sealed motor then you may be seeing the failure due to overheating/lack of cooling. I just went through this with a farm here outside of Town where the guy was burning up fan motors every yr. All of them were sealed and he insisted they had to be sealed for dust/moisture. I talked him into trying 2 new fans that were vented, it has been 2 yrs now and they are still going strong. Motors are very tough. I have seen them submerged in water, dried out and run fine. At the local garnet mine i saw motors run 24-7 for 20yrs covered in garnet dust/sand. We used to hit them with a rubber mallet when they slowed down so they would blow themselves out the dust build up inside. The dust would shoot out and the motor would pick up speed and keep right on a running. But anytime i have found a failed motor heat was usually the factor. 

I would check to see if it is a sealed motor or not and check the temps while the kitchen is operating around the fan unit. I would expect 140-160 deg temps.


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## EarthQuakens (Nov 6, 2012)

I do a lot of bar and restaurant work and these hood exhausts are just kind of a poor design. They go through belts like crazy and motors like crazy. I have extended some life on them by taking them out and cleaning them but eventually all the heat and grease does its number on them. If you have a maintenance plan with them like I do I now keep an extra motor and a few belts for emergency. And when one goes bad you can have it rebuilt usually


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## TimPa (Jan 26, 2010)

ended up not locating a tefc, so put an odp back in. motor is actually outside but enclosed in an aluminum shroud. it runs about 16 hrs/day.


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## billgl (Dec 3, 2013)

woodchuck2 said:


> Are these motors sealed or vented? This post will contradict what i posted above but i have seen motors fail prematurely from heat. Normally in a kitchen grease gets into everything and why i would recommend a sealed motor. But, now we have to look at how hot this motor is getting too. If it is a sealed motor then you may be seeing the failure due to overheating/lack of cooling. I just went through this with a farm here outside of Town where the guy was burning up fan motors every yr. All of them were sealed and he insisted they had to be sealed for dust/moisture. I talked him into trying 2 new fans that were vented, it has been 2 yrs now and they are still going strong. Motors are very tough. I have seen them submerged in water, dried out and run fine. At the local garnet mine i saw motors run 24-7 for 20yrs covered in garnet dust/sand. We used to hit them with a rubber mallet when they slowed down so they would blow themselves out the dust build up inside. The dust would shoot out and the motor would pick up speed and keep right on a running. But anytime i have found a failed motor heat was usually the factor.
> 
> I would check to see if it is a sealed motor or not and check the temps while the kitchen is operating around the fan unit. I would expect 140-160 deg temps.


The motor would have to be sealed. Because like you mentioned in a kitchen grease gets into everything, not to mention who knows what else so I think a sealed motor would have to be a requirement at this point.


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## flashheatingand (May 3, 2008)

Motors are supposed to last a zillion hours. Maybe too much heat (not enough air flow) lack of cleaning filters?


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## EarthQuakens (Nov 6, 2012)

If they don't clean their hood often and clean the filters daily the motor will get over ran with grease and it even gets hotter in there. Thus laziness and lack of cleaning makes parts go bad faster. The motor is sealed inside the unit so check out how much grease is In there. They are supposed to have it cleaned every so often depending on how much use it gets.


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## EarthQuakens (Nov 6, 2012)

I'm talking professional hood cleaning company not Joey DoitAll down the street. I know my client gets his cleaned every other month and they clean the filters every night. Still burns up a motor every year and a belt about 2 times a year on each hood


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## EarthQuakens (Nov 6, 2012)

You also can't use an explosion proof in greasy environments it will lock up tighter than the hubs of hell in a week. Best thing is to fix it up right make sure ur belts level and tight give em a card tell them to call ya if it stops sucking again. It's just one of those things that gets used a lot and goes bad.


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