# electrical whole house fan motor question
**URL:** https://boards.straightdope.com/t/electrical-whole-house-fan-motor-question/515329
**Category:** Factual Questions
**Created:** [October 27, 2009, 6:52pm UTC](https://boards.straightdope.com/t/electrical-whole-house-fan-motor-question/515329 "2009-10-27T18:52:04Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@Magiver](https://boards.straightdope.com/u/Magiver)
#### Post date: [October 27, 2009, 6:52pm UTC](https://boards.straightdope.com/t/electrical-whole-house-fan-motor-question/515329/1 "2009-10-27T18:52:04Z")
I installed a pull switch on a whole house fan that was originally 2 speeds and now I’m getting 3 speeds. It appears it is feeding both sets of windings versus just each set individually on the 3rd speed. Is this going to be a problem?
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### Author:  [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)
#### Post date: [October 27, 2009, 8:44pm UTC](https://boards.straightdope.com/t/electrical-whole-house-fan-motor-question/515329/2 "2009-10-27T20:44:50Z")
I’m curious about this as well, if only from the standpoint of an idle observer.
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### Author:  [@Shot\_From\_Guns](https://boards.straightdope.com/u/Shot_From_Guns)
#### Post date: [October 27, 2009, 9:30pm UTC](https://boards.straightdope.com/t/electrical-whole-house-fan-motor-question/515329/3 "2009-10-27T21:30:45Z")
This is not nearly as exciting as an “electrical whore house fan motor question,” which is what I originally mistook it for.
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### Author:  [@HongKongFooey](https://boards.straightdope.com/u/HongKongFooey)
#### Post date: [October 27, 2009, 9:34pm UTC](https://boards.straightdope.com/t/electrical-whole-house-fan-motor-question/515329/4 "2009-10-27T21:34:31Z")
When you say it appears to be feeding both sets of windings do you mean it’s going slower than before on one speed? It might not be able to cool itself if running slower on hot days.
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### Author:  [@beowulff](https://boards.straightdope.com/u/beowulff)
#### Post date: [October 27, 2009, 9:43pm UTC](https://boards.straightdope.com/t/electrical-whole-house-fan-motor-question/515329/5 "2009-10-27T21:43:09Z")
Look at the motor’s wiring diagram. It’s usually right on the nameplate. If not, get the make / model and post it, and I’ll try to look up the correct wiring.
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### Author:  [@Magiver](https://boards.straightdope.com/u/Magiver)
#### Post date: [October 27, 2009, 10:38pm UTC](https://boards.straightdope.com/t/electrical-whole-house-fan-motor-question/515329/6 "2009-10-27T22:38:14Z")
> [@beowulff](#):
>
> Look at the motor’s wiring diagram. It’s usually right on the nameplate. If not, get the make / model and post it, and I’ll try to look up the correct wiring.
I took the original switch apart. it is a single input feeding 2 lines one at a time. It could only work by feeding 1 set of windings and then another. There are only 2 input leads (plus ground) on the motor. What the new switch appears to do is feed the first set of windings, then both, and then the 2nd set of windings (thus giving 3 speeds). the result is medium speed, then high speed, and then low speed (the order could be reversed). Is this how 3 speed motors are usually set up or are they always 3 sets of windings?
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### Author:  [@HongKongFooey](https://boards.straightdope.com/u/HongKongFooey)
#### Post date: [October 27, 2009, 11:41pm UTC](https://boards.straightdope.com/t/electrical-whole-house-fan-motor-question/515329/7 "2009-10-27T23:41:30Z")
If both windings in give you the highest speed then they are in parallel. The only concern I would have is that you aren’t suddenly drawing more than the breaker was selected for.
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### Author:  [@beowulff](https://boards.straightdope.com/u/beowulff)
#### Post date: [October 27, 2009, 11:50pm UTC](https://boards.straightdope.com/t/electrical-whole-house-fan-motor-question/515329/8 "2009-10-27T23:50:33Z")
I’m guessing that your new switch is not correct for this motor, and you might overheat it. Take a look at this: [http://www.butcherdistributors.com/Images/Interior/motor%20catalog.pdf](http://www.butcherdistributors.com/Images/Interior/motor%20catalog.pdf)
There is a lot of motor info here.
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### Author:  [@Magiver](https://boards.straightdope.com/u/Magiver)
#### Post date: [October 28, 2009, 2:04am UTC](https://boards.straightdope.com/t/electrical-whole-house-fan-motor-question/515329/9 "2009-10-28T02:04:05Z")
> [@beowulff](#):
>
> I’m guessing that your new switch is not correct for this motor, and you might overheat it. Take a look at this: [http://www.butcherdistributors.com/Images/Interior/motor%20catalog.pdf](http://www.butcherdistributors.com/Images/Interior/motor%20catalog.pdf)
> There is a lot of motor info here.
Sigh… After looking at switches for an hour there are clearly ones designed to feed both circuits as a 3rd speed. What part of 2-speed switch did the person I bought it from not understand.
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### Author:  [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)
#### Post date: [October 28, 2009, 2:13am UTC](https://boards.straightdope.com/t/electrical-whole-house-fan-motor-question/515329/10 "2009-10-28T02:13:29Z")
I’d say this is when you either put the old switch back or hire an expensive licensed electrican to check out your install. ☹
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### Author:  [@Magiver](https://boards.straightdope.com/u/Magiver)
#### Post date: [October 28, 2009, 4:25am UTC](https://boards.straightdope.com/t/electrical-whole-house-fan-motor-question/515329/11 "2009-10-28T04:25:04Z")
> [@carnivorousplant](#):
>
> I’d say this is when you either put the old switch back or hire an expensive licensed electrican to check out your install. ☹
It’s operationally fine, it’s just a matter of whether the motor will handle the heat of running both windings at the same time. I’s a more efficient way of making a 3 speed motor. I’m going to swap a true 2-way in when I get the chance. There’s nothing to be gained by a higher speed on a whole-house fan unless you want to suck the fir directly off your pets.