# Wiring motor for air filtration box



## beelzerob (May 2, 2010)

I got a free blower from my HVAC guy, so I mean to make my own air filtration box and hang it from the ceiling.

This is actually my *second* free squirrel cage and motor. The first one, I wired up the motor to an extension cord, based on what I had been told the wires were (black was neutral, red was "high"...there was no white). Well, a screaming motor, popped 20 amp breaker, and a *terrible* smell later, I now believe those weren't the right wirings.

So this new motor is much simpler....a white, black, and red. And this time, the HVAC buy labelled each wire as he took them off, so I know black is high, white is neutral, and red is low. I've already wired it up, and it works great.

I'd like to have the option of using low speed too. For low, do I just simply wire my "hot" wire to that instead of to high? Or does the low wire require something other than 120v? I had also thought I'd get one of those simple Off/Low/High rotary switches so we can choose how much filtering/noise we want in the shop. Is it that simple, as far as wiring this thing?

Thanks


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## woodnthings (Jan 24, 2009)

*Yup*

You can use a rotary or a 2 position rocker. The switch won't care or know the difference. It will just alternate between red and black.
The rocker or toggle is probably cheaper and more available.  bill
BTW I have one hooked to a 3 way rotary from a furnace blower.


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## beelzerob (May 2, 2010)

Excellent, thanks. I hooked up the blower and got it going, and my wife was already complaining about the noise, so I can see wanting to run it on low instead.

I'm not sure what to do with this other blower. I'm a bit afraid to try and run it again, and I wouldn't know which wires to use even if I did. I'm thinking of removing the motor and keeping the squirrel cage, in case I come across another motor some day. I don't know if the motor is actually trashed or not, but it *screamed* for a while and then began to slow down before I actually unplugged it. My volt meter I had plugged into the extension cord flashed 27 amps and almost gave up the ghost. The motor itself was rated for 9 amps.


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## rrbrown (Feb 15, 2009)

beelzerob said:


> Excellent, thanks. I hooked up the blower and got it going, and my wife was already complaining about the noise, so I can see wanting to run it on low instead.
> 
> I'm not sure what to do with this other blower. I'm a bit afraid to try and run it again, and I wouldn't know which wires to use even if I did. I'm thinking of removing the motor and keeping the squirrel cage, in case I come across another motor some day. I don't know if the motor is actually trashed or not, but it *screamed* for a while and then began to slow down before I actually unplugged it. My volt meter I had plugged into the extension cord flashed 27 amps and almost gave up the ghost. The motor itself was rated for 9 amps.


Squire cage motor's are not designed to run with out the airflow being blocked off partially on the motor side. If you have to much air flow in it can over amp. I usually block off 2/3 to 3/4 of the motor side hole. that leaves enough air flow to cool the motor and keeps it running properly.

I have a 3 speed 4 ton blower I am making into a air filtration system. A little over kill but I plan on having the 3 speed switch so I have options.:laughing:


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## Locodcdude (Oct 24, 2010)

I actually made my own air filtration box out of a blower that my dad got off a job. It works amazing, and IMO, works better than any jet model considering the speed of the fan. This blower is meant to circulate air throughout an entire house! In your position I would wire this fan to a switch that has 3 settings, your high low and off. My fan's wiring was ripped out and was only left with your basic black white and green. So I wired it to an extension cord and I plug it in if I need power to it for some reason. Speaking of projects, Maybe I will put a switch to it tonight :]


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## beelzerob (May 2, 2010)

Oh it wasn't because of too much air....the motor didn't overheat (unless that can happen within 10 seconds), it just wasn't wired like how it was supposed to be. I'll probably never know how I actually had it wired, and what affect that could have...but it clearly wasn't given power on the wire it should have had power on.


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## rrbrown (Feb 15, 2009)

beelzerob said:


> Oh it wasn't because of too much air....the motor didn't overheat (unless that can happen within 10 seconds), it just wasn't wired like how it was supposed to be. I'll probably never know how I actually had it wired, and what affect that could have...but it clearly wasn't given power on the wire it should have had power on.


If it's wired to high and part or most of the motor side is not blocked it will over amp and pretty quick. I'm not saying it was that but possible. at least you got the other one working. 
I plan on using a cheaper filter on the outside and a HEPA filter inside of that. the cheaper filter will help the good one last longer.


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## beelzerob (May 2, 2010)

Ya, I've got the same plan. I found some $1.50 cheap filters at the local surplus store, and bought the better filters at lowes. I'm just going to stack one filter on top of the other. I've heard a space between is useful, but that just complicates the design.


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## beelzerob (May 2, 2010)

When buying hardware for this thing, I bought a long piano hinge, thinking I'd use it to make a door to access the inside of the air filter box....is there really any need to? The air filters will be accessible from the outside, so I don't need to get inside for those. The motor is directly connected to the fan, so there is no belt to adjust. If something goes wrong with the motor, I'm more than likely going to be taking the box down from the ceiling and tearing it apart. Sooo...there's probably no real reason to put an access door on the box, is there?


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## Nick Ferry (Feb 23, 2011)

I will be building an ambient air filter to hang from my shop ceiling. Will be from 1/2" ply and furnace fan most likely. Any tips? anyone build one before? Results? Shop is 22' x 22' 10' ceiling

I am thinking dims of 30"L x 16"T x 24" wide or so w/ double or triple filters with the cheapest filter as a pre filter and an inner 13merv .5micron on the inner.

Will post pics when built but it will be a month or so. 

Anyone know of an online place for blower and cage on the cheap?


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## rrbrown (Feb 15, 2009)

beelzerob said:


> When buying hardware for this thing, I bought a long piano hinge, thinking I'd use it to make a door to access the inside of the air filter box....is there really any need to? The air filters will be accessible from the outside, so I don't need to get inside for those. The motor is directly connected to the fan, so there is no belt to adjust. If something goes wrong with the motor, I'm more than likely going to be taking the box down from the ceiling and tearing it apart. Sooo...there's probably no real reason to put an access door on the box, is there?


No need for the hinge. Just put the box together with screws.



wfs said:


> I will be building an ambient air filter to hang from my shop ceiling. Will be from 1/2" ply and furnace fan most likely. Any tips? anyone build one before? Results? Shop is 22' x 22' 10' ceiling
> 
> I am thinking dims of 30"L x 16"T x 24" wide or so w/ double or triple filters with the cheapest filter as a pre filter and an inner 13merv .5micron on the inner.
> 
> ...


Blowers are usually not cheap unless you know someone. 3 filters may be over kill, 2 should do.


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## Nick Ferry (Feb 23, 2011)

thanks i will try two - i have a call into my friend in th HVAC biz , hopefully he can get me one


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## mdntrdr (Dec 22, 2009)

beelzerob said:


> Sooo...there's probably no real reason to put an access door on the box, is there?


 
Some older motors require lubrication, if it is sealed, then you may have enough access through filter opening. :smile:


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## beelzerob (May 2, 2010)

Hmm...there were some kind of labels on the outside of the motor that talked about lubrication, but I kinda ignored it. Oops. So I really will have to?? Never lubed a motor before.


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## rrbrown (Feb 15, 2009)

mdntrdr said:


> Some older motors require lubrication, if it is sealed, then you may have enough access through filter opening. :smile:





beelzerob said:


> Hmm...there were some kind of labels on the outside of the motor that talked about lubrication, but I kinda ignored it. Oops. So I really will have to?? Never lubed a motor before.



I don't remember any needing lubrication but it's been a long time since I worked in the field. If they do need lubrication it can be done with a removable panel by the motor. When they are in place in the system there is an access door by the blower anyway so just make an access panel. Problem solved if needed.


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## BWSmith (Aug 24, 2010)

On ours,the motor sits on top of squirrel cage and drives the fan via a belt.This is handy 'cause you can play with pulley/sheave size to get your amp load correct.It also makes yearly inpection/cleaning/lubricating a breeze.And gets motor out of explosive environs.

I didn't enclose the SC(squirrel cage),just made a filter housing that bolts dirrectly to it.Theres a round inlet on SC that simply needs to be changed to square filter size on inlet....other side of SC has sheet metal cvr riveted to close off.Our filters just slip in from bttm of sq housing,no disassembly whatsoever.....just jerk'm out and replace.BW


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## Ahlem (Nov 28, 2010)

Before you get too deep into the project be sure you figured out what to do in the case of a fire in a home made blower set up. Some of the motors tend to spark on start up. Turn off all the lights and see if it's obvious. Watch Mythbusters and see what you can do with some fine dust like coffee creamer or fine sanding sawdust.


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