220 volt attic fan with two switches and a thermostat?

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  #1  
Old 06-29-11, 04:17 PM
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220 volt attic fan with two switches and a thermostat?

Hello everyone,
I need help with my attic fan. This is what I have:
From the circuit breaker are 3 wires. They are white, red, and black. Testing from the white to black i get around 120 volts. Testing from white to red I get around 120 volts.
I cannot read the manufacturer of my motor but there are 10 wires coming from the motor. Four are for changing the rotation from ccw to cw and vice versa; two brown wires go to a capicator; and 4 wires are left. These are white, red, black and a small green wire.
On the side of the motor is a diagram which reads white - line ; black (hi) and red (lo) then a picture of a switch then says -line . I can somewhat understand this but now it gets complicated:
Now we introduce two switches. The first switch has the black and the red attached to the bottom. from this switch the black exits and goes to a thermostat, leaves the thermostat and runs to the second switch. The white wire from the breaker attaches to the metal switch box (like a ground wire) and the green ground wire from the motor attaches to this as well.
Even more confusing is I do not know where the red, black and white from the motor should connect. This should be clear as mud now but it all seemed to work before I disconnected the red, black and white from the motor.
In the past the first switch would turn on and off the fan completely (so I assume the red from the fan goes to the top of the first switch). The second switch did nothing at all. The second switch has 3 terminals. In one position I get continuity between the bottom and top left terminal. In the other position I get continuity between the bottom and top right terminal. Where do the wires go?
Should I just start over somehow? I will work on a drawing or some pictures if that will help...
 
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  #2  
Old 06-29-11, 04:28 PM
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Yes, pictures of the motor diagram and of the connections at the motor and switches would help. http://www.doityourself.com/forum/el...your-post.html

Is this a whole house fan (sounds like that) or a roof vent fan. What is the make and model number of the fan motor? Is it on a 2-pole or single pole breaker?
 
  #3  
Old 06-29-11, 04:43 PM
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I'm working on pictures and /or a drawing.........
This is a gable mounted attic fan taking up two spaces in my circuit breaker box. I am still trying to read the sticker for the make of the motor but this is what I got from it so far:
Eldon Mo Div , Type U26B1 , v 208/230, 60hz ph1 , 1/3-1/4 hp, model D737, amp 3.2 -2.5, no. 7126-0120 , rpm 1075-975 .
 
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Old 06-29-11, 05:52 PM
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I'm working on pictures and /or a drawing.........
This is a gable mounted attic fan taking up two spaces in my circuit breaker box. I am still trying to read the sticker for the make of the motor but this is what I got from it so far:
Eldon Mo Div , Type U26B1 , v 208/230, 60hz ph1 , 1/3-1/4 hp, model D737, amp 3.2 -2.5, no. 7126-0120 , rpm 1075-975 .
There ya go, that would be a Fasco motor, call them.



Fasco started with one manufacturing plant in Rochester, N.Y. in 1911. Today, we employ over 5,000 individuals in 13 facilities across North America and Asia Pacific and are continually increasing our capabilities on a global scale.

North America

United States

Beloit Wisconsin - Regal Beloit Corporate Headquarters
Springfield, Missouri - FASCO Headquarters
Cassville, Missouri
Eldon, Missouri
Fasco - Fasco Locations
 
  #5  
Old 06-30-11, 06:59 AM
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Joe: I appreciate the help but wish I shared your enthusiasm :-) .... the info is needed but doesn't clear up my current wiring situation. I am attaching a picture from the internet of the newer version of the wiring diagram on the motor. For what it is worth, before I unhooked the motor it was working via thermostat and the first switch would kill all power to the motor. I never saw any hi/lo though, the second switch did nothing.
.
End result I would like to have the fan come on via thermostat as well as have the power switch to kill power at the fan. Do I need hi/lo?
PS....should the fan be blowing air into the attic or out of the attic? I seem to remember it blowing air into the attic but that makes no sense either.
Thanks!!
 
  #6  
Old 06-30-11, 08:42 AM
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You need to submit your photos in a viewable size. Use the "direct link" choice at Photobucket.
 

Last edited by ray2047; 06-30-11 at 09:07 AM.
  #7  
Old 06-30-11, 09:24 AM
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pictures

crawled back into the attic for some pictures....
Pictures by duigoose - Photobucket and specifically [IMG][/IMG]
 
  #8  
Old 06-30-11, 11:57 AM
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If you don't want to use the fan in low speed mode you can ignore the red wire entirely; just cap it off.

I've only seen attic fans blow out of the attic, but my climate is a lot different than yours so they might do it differently there.
 
  #9  
Old 07-01-11, 03:58 PM
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big what ifs

Thanks so far folks but I need more clarity. I am just going to start over here but have some questions. WHAT IF I ran the black and red wires from the breaker to the bottom of the switch then out the top of the same switch then connected them to the black and red wires of the fan respectively. I would then connect the white wire from breaker to the white wire of the fan. Would that then give me the motor running constantly at high speed with the switch on? WHAT IF I connected the thermostat into the black wire between the switch and the fan? To me that would give the motor 110 from the red unless the thermostat was 'on' which would then give the motor 220 (red and black). Is that what it wants? Would that run on lo until the thermostat kicked in which would then run on hi?
ibpooks: I don't doubt you I just cant wrap my brain around the 220 motor being happy only on the 110 from the black wire.....
 
  #10  
Old 07-01-11, 04:49 PM
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The first question is why is there a neutral. If this is a 240v motor you don't use a neutral.. If this is a 240v motor then the white should be capped off and not used. As you said in your first post:
The white wire from the breaker attaches to the metal switch box (like The white wire from the breaker attaches to the metal switch box (like a ground wire) and the green ground wire from the motor attaches to this as well.a ground wire) and the green ground wire from the motor attaches to this as well.
As your pictures show this is a 240v motor. To be code compliant you can't use the white wire as ground which is what they did. If you are not going to bring this up to code compliant then cap off the white. Forget it exists.

If you are going to bring this up to code compliant, which I strongly recommend, you need to replace the 3-conductor cable with 2-conductor NM-b Romex with ground*. It will then be code compliant once you recolor the white on both ends red, or black or some color other then green or gray.

Yes, the code permits in some special cases recoloring #6 or smaller white hot but not as a ground. This is one of those cases. If you want you could recolor the white green on both ends still not code but maybe better. *You could also just run a bare or green ground wire from the panel, use the existing cable, and abandon the white. That would be code compliant.
 

Last edited by ray2047; 07-01-11 at 05:18 PM.
  #11  
Old 07-01-11, 05:11 PM
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thanks ray, that clears it up a little for me. Does the rest of my what if make sense then? The black and the red being switched together as master power and the thermostat being on the black wire, red going straight to the motor, and the white from the motor being capped off? Then run the green wire to the ground wire. Is that what I need to do as it sits? I have no problem running new wire to bring it up to code but need to understand the rest. If I brought it up to code will I still not have a capped off white wire from the motor?
 
  #12  
Old 07-02-11, 12:49 AM
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I will clear up few confusing facts on 240 volts single phase motour which I have see and run from time to time.

Now for white wire from the motour that you do need it and if you cap it off it will NOT run at all.,,

So that white wire from fan motour is what we call L2 so hook that one to red supply wire { from the house side } btw you will need double pole switch per NEC code requirement for safety issue and you will need single pole three way switch I will fill you in a moment with that one.

If you want both high and low speed then use the three way switch however the connection will be little tricky if not heed on this one.

The travellers screws { bright brass } use that from the red or black leads from motour while the dark screw aka common screw that is L1 or line { it will be black wire from your building wire } to change the speed.

If you only want one speed then cap either black or Red conductor From motour ( depending on the speed )

That should take care the misunderstood with wiring connection on the motour and legit 208-240 volt single phase motour DO NOT use any netural at all.

Merci,
Marc
 
  #13  
Old 07-02-11, 06:04 AM
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the white from the motor being capped off?
No. the motor white is used. Only the white from the breaker box is capped. Sorry if I wasn't clear. The motor white is one of the two motor power leads. Does the existing cable have a bare ground?
 
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Old 07-02-11, 09:06 AM
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THANK YOU THANK YOU THANK YOU!!
That is exactly the information I was looking for. I am on another project at the moment but will get into the attic today, hook it up and let everyone know the outcome.
and no, the existing cable (from breaker) does not have a bare ground but I understand what you were saying about them using the white as ground and about bringing it to code. As usual I will let everyone know the final outcome in case they run into the same problem.
 
  #15  
Old 07-02-11, 11:22 AM
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Thanks everyone,
I hooked the white wire from the motor to the top of the double pole switch that has red from the breaker on bottom and hooked the red and black wire to the top of the 3 way switch that has black on the bottom. The double pole switch cuts power to the fan and the 3 way controls the hi/lo ...... just as you expected!!
Thanks everyone!! now i'll run new wire for code and understand how the motor is wired!!
 
  #16  
Old 07-02-11, 12:04 PM
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Good job. Thanks for letting us know.
 
  #17  
Old 07-02-11, 07:50 PM
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I am glad it turn out really nice and you can understand how we describe this one.

Merci,
Marc
 
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