# AC Compressor Fan Motor Wiring



## frankleibo (Jun 1, 2011)

Replacing ac compressor fan motor. Old motor was a 20+ year old GE motor with 3 wires. From the motor: Black wire went to contact relay. Purple wire went to one lead of capacitor. Brown wire went to other lead of capacitor. There was a blue striped wire that also went into one of the capacitor leads. but wasn't from the motor. New motor is Wagner 840729. Can't figure out wiring. I am thinking the two brown wires should go to the leads of the new run cap. The blue striped wire attaches to one of the cap leads. Yellow and black go into contact. Did I get this right?


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## hvactech126 (Nov 11, 2010)

what does the striped wire go to? everything else you said is correct


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## frankleibo (Jun 1, 2011)

the striped wire is coming from the black box attached to the compressor. in the old configuration the wire was pigtailed to the run cap with the other end directly to line power.

also, can i attach the yellow wire to the contactor relay by the push on lug terminla or does it have to go under a screw terminal.


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## hvactech126 (Nov 11, 2010)

connect the striped with the yellow to the contactor and yes you can use a spade connection.


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## frankleibo (Jun 1, 2011)

Thanks for the help. Sorry to be a pest here, just want to make sure I am clear on this blue striped wire because my gut instinct is to rewire it the way it was before which would mean I would attach it to the cap. In the old and new config I am using a run capacitor just of appropriate size to drive the fan motor. Why does the blue striped wire now go to the contactor instead of the capacitor as it did in the previous config?


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## hvactech126 (Nov 11, 2010)

the previous config used the the common wire from the contactor to the cap there by actually being connected to the contactor, the new config uses no wire directly from the contactor to the capacitor


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## frankleibo (Jun 1, 2011)

just wired as you suggested and heard a single clicking noise from the compressor and fan did not start....


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## hvactech126 (Nov 11, 2010)

can you take a picture of your wiring....


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## frankleibo (Jun 1, 2011)

i'm thinking there might be some other problem. after trying what you suggested I decided to wire similar to my original configurations....the black wire with blue stripe wired to the cap and the yellow wire to the contactor. when i did this the unit behaved just as it did before i replaced any parts. that is, the compressor sounded like it kicked on and was trying to do its thing but the fan did not run and the unit got very hot very fast. at this point i killed the power. 

i do have some folks coming out to give me estimates on a new ac. this is probably a 20-30 year old system that looks to be 100% original. I was just hoping to do a quick hold me over fix until i got a new system installed. what do you think?


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## hvactech126 (Nov 11, 2010)

need to see how its wired...


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## frankleibo (Jun 1, 2011)

Picture Key:

1. Full exterior shot.
2. Wires coming out of new fan motor. Yellow, Black, Brown, Brown Stripe
3. New fan motor capacitor. Currently wired with brown and brown stripe wire from fan motor. You can also see the blue striped wire that I have attached to the cap.
4. Shot of the 3 system capacitors.
5. Another capacitor shot.
6. Contactor relay. You can see the yellow wire from fan motor, the black wire from the fan motor (the one with the new looking red crimp connector). In this shot you can also see the pigtailed blue stripe wire.


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## frankleibo (Jun 1, 2011)

Picture Key:

7. Wide shot so you can see where the blue striped wire is coming from.
8. Another close up of blue striped wire
9. The other end of the blue striped pigtail.


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## hvactech126 (Nov 11, 2010)

You have a very old GE condenser. The black wire from the fan and the striped wire from the compressor go to opposite incoming wire as what goes to contactor. Yellow to contactor... brown and brown/white to opposite sides of new capacitor. This should get the fan running....


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## frankleibo (Jun 1, 2011)

OK, the good news....wired as you said in previous post....got the fan going...made me happy for a second.

the bad news....major smoke coming from the contactor relay....killed power before I burned the house down.


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## hvactech126 (Nov 11, 2010)

hmmm that doesn't make any sense! Sounds like it might be a sign.......


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## frankleibo (Jun 1, 2011)

yeah it just might be a sign. it's dark now so I will have to check out the damage in the morning and see what exactly got burned up. like i said this thing is old old old and I fully expect to be replacing it very soon. thanks for your help in any case.


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## frankleibo (Jun 1, 2011)

took a quick look this AM before heading to work to see what was burning from last night. under the contactor relay is some sort of insulating fabric. This was all burned up.


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## hvactech126 (Nov 11, 2010)

fabric? Not sure there unless somehow something was trying to ground it self, or was grounded improperly or shorted to ground...........


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## frankleibo (Jun 1, 2011)

Turns out the fabric was covering the coil on the relay. Apparently whatever I did wiring wise yesterday smoked the coil. Brought it to the HVAC supply and said "I need one of these". Guy was like what is it. Its a contactor relay....oh I've never seen one like this, must be the first one ever made. As we already know my system is pretty much ancient. Buddy of mine came over and we figured out how to wire the new relay...used the 3 wire motor connection instead of 4. Everything is back up and running...house is cool and I am happy. Just need to get through the summer and then a modern system will be installed!


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## permagrin (Aug 31, 2011)

Hi Folks,

I have the same issue, going from a 3 wire to 4 wire compressor fan motor. I currently have a dual cap and the motor electrical diagram shows the brown and brown/white wires both going to the cap. Can both of those wires attach to the dual cap fan leads? Each of the 3 sections of the cap has 4 leads with only one on each currently being used for the power supply, Herm, and fan sections. Can I just attach both wires to the fan section since there are 4 leads on that section sticking out? Thanks in advance.


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## permagrin (Aug 31, 2011)

Think I may have it wrong. Does the brown/white wire simple connect to the dual cap common and the brown the dual cap fan lead? Then the white and black connect directly to the contactor as the original motor white and black wires did? The question about connecting to multiple leads on the same cap section still holds though, I can connect the brown/white from the motor to the cap common even though the power connects there as well correct? If so is this effectively the same thing as wiring the brown/white to the same side of the contactor the dual cap is wired to or is it different due to the cap charging physics?


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## JJboy (Oct 12, 2010)

:thumbsup:


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## permagrin (Aug 31, 2011)

Thanks JJ,

The cap I have is a dual cap. I've modified your diagram to show what I have currently. There is a wire from the compactor to the dual cap supplying the line power (old 3 wire motor wiring), is this still needed or is the brown/white that attaches from the motor now providing the line power to the cap and I should remove the old wire? I assume yes but for fear of opening up a wormhole to another dimension would like to verify. Thanks.


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## JJboy (Oct 12, 2010)

You need wire from (C) on dual capacitor to the contactor

On the dual capacitor, you connect (H or yellow mark ) to compressor.


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## kwicklund (Jul 12, 2012)

*emerson a/c compressor fan*

was wondering if you knew about the wiring of an emerson fan motor with 6 wires to a ac compressor? thanks for any help you can provide


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## kwicklund (Jul 12, 2012)

*wiring help*

hey noticed you were on, need some help if you can with wiring an emerson fan motor that has 6 wires, i am assuming 3 are for speed control so it would only be 4 wires in use at a time, i have 2 brown and an orange and a red, black, and blue. lil help please


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## JJboy (Oct 12, 2010)

Check in my album...:thumbsup:


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