View Full Version : A/C fan motor installation
freddmar
Oct 26, 2009, 12:03 PM
The model is an AO Smith #F48K93A01.
The wires to the capacitor are the brown; brown & white. Rotation are the black and white wires... Here is where I am confused... diagram shows yellow wire and black wire going to the line.
What line? Where should this line be?
KISS
Oct 26, 2009, 12:44 PM
There is no universally accepted color code. In fact, some motors have 3 wires and others have 4. One is internally connected to the capacitor.
LINE and LOAD are universally accecpted terms. LINE, meaning POWER LINE voltage; LOAD being this like motors and heaters. LINE also means power in.
In your case, the browns go to the capacitor. With AC capacitors, there is no polarity.
Black is HOT and White is NEUTRAL. Usual connections. White is probably connected to one of the browns.
ptcpaul01
Oct 26, 2009, 12:57 PM
Kiss is right
hvac1000
Oct 26, 2009, 02:05 PM
See here
czadna
Oct 26, 2009, 08:25 PM
There is no universally accepted color code. In fact, some motors have 3 wires and others have 4. One is internally connected to the capacitor.
LINE and LOAD are universally accecpted terms. LINE, meaning POWER LINE voltage; LOAD being this like motors and heaters. LINE also means power in.
In your case, the browns go to the capacitor. With AC capacitors, there is no polarity.
Black is HOT and White is NEUTRAL. Usual connections. White is probably connected to one of the browns.
I have just replaced the fan motor in my Tempstar 5000 condenser. The old motor had only 3 wires coming out of it: Black, Red and Brown.
The new motor has Black, Yellow, Brown and Brown/White. I know Brown or Brown/White should go to the capacitor but, I have a dual start capacitor that has 3 connections on the top: Compressor, Fan and Common. Do I put both Brown wires on the Fan terminal? I really can't afford to screw anything up.
czadna
Oct 27, 2009, 05:52 AM
I have just replaced the fan motor in my Tempstar 5000 condenser. The old motor had only 3 wires coming out of it: Black, Red and Brown.
The new motor has Black, Yellow, Brown and Brown/White. I know Brown or Brown/White should go to the capacitor but, I have a dual start capacitor that has 3 connections on the top: Compressor, Fan and Common. Do I put both Brown wires on the Fan terminal? I really can't afford to screw anything up.
Stratmando
Oct 27, 2009, 06:11 AM
I would think their would be a small diagram on Motor showing Capacitor and Power connections.
If I was to guess, and I won't, it would be capacitor across the brown and brown/white.
Power to Black and Yellow.
Is the Fan using part of the capacitor? Or is it just for Compressor?
KISS
Oct 27, 2009, 06:50 AM
There is usually a diagram on the motor. Usually, the motor cap is replaced when the motor is replaced.
Polarity is imaterial. As lomg as the cap wires are correct and the line wires are correct, your good to go.
The three terminal capacitor has a common terminal.
Usually, one would disconnect the motor and add a new capacitor in a different location.
The replacement motor may use a different value.
So, independently connect the new cap. Now you have 2 wires left. One will go to the common terminal and the other will go to the contactor. (it's wire went to the capacitor in a 3 wire setup)
Remember that in a 4 wire setup, 2 of the wires are connected together internally. Four wires makes it a bit easier for retrofit applications. Also remember --> Niew motor... replace capacitor.
czadna
Oct 27, 2009, 07:21 AM
As I stated, the capacitor is a dual start that runs the compressor and the fan. The diagram on the motor shows the brown wire on one side of the capacitor & the brown/white on the other side of it. The capacitor has only 3 positions - Compressor, Fan & Common. There are 4 blades for each of the 3 positions on the top of the capacitor.
czadna
Oct 27, 2009, 07:30 AM
I already replaced the capacitor with a new one that has identical values as the old one. The only thing that is different between the motors is the # of wires, the color of the wires and the RPM (old motor: 1150rpm; new motor 1075rpm).
On the old setup, the brown wire from the motor splits and goes to both the capacitor and the contactor. Should I run the brown to the capacitor and, the brown/white to the contactor? Or, vice-versa?
KISS
Oct 27, 2009, 08:49 AM
Ok, try again.
The new motor has 4 wires. Go to the new capacitor. You know which ones they are. Wire hem to the capacitor. Polarity doesn't matter. Your done wit the new motor capacitor wires.
You have two wires left. They go to power, 240 VAC power to be exact. One of these will go to the COMMON terminals of the three wire capacitor. It went to the old motor a terminal of the contactor together.
Now the old motor was connected to the other pole of the contactactor. The other power wire goes there.
Look at it this way: The capacitor is the capacitor. Leave it independent on the new motor capacitor.
Now the motor needs power. 240 VAC (LINE in) will connect to the contactor. The contactor will connect to the fan and compressor. Follow the electricity. From the wall to the contactor, to the fan motor, return out of the fan motor, to the other side of the contactor and back to power.
A quick test. Once it's connected, manually push the contactor with something insulated briefly. The compressor and fan should both start.
czadna
Oct 27, 2009, 12:48 PM
This is a drawing of how the old motor was wired. You'll see the new motor in the top left and, why I am questioning how to wire it. I assume the YELLOW WIRE will replace the RED WIRE and, the BLACK WIRE will be the same. How should I connect the BROWN WIRE & BROWN/WHITE WIRE ?
KISS
Oct 27, 2009, 01:31 PM
Black and Red OLD, become Black and Yellow of NEW motor, respectively. (polarity doesn't matter, but Black to black makes sense.
Disconnect Brown of the OLD motor. (F) stays unconnected.
Brown & Brown/white go to new capacitor. Again, polarity doesn't matter.
czadna
Oct 27, 2009, 01:35 PM
Black and Red OLD, become Black and Yellow of NEW motor, respectively. (polarity doesn't matter, but Black to black makes sense.
Disconnect Brown of the OLD motor. (F) stays unconnected.
Brown & Brown/white go to new capacitor. Again, polarity doesn't matter.
You have totally lost me. You say "F" stays unconnected but, then to connect the BRN & BRN/WHT wires to the capacitor. Which is it? Does it matter where on the capacitor the wires get connected? Don't they go to the "F" terminal?
The BROWN wires are my concern. I'm okay about YELLOW replacing RED.
The 3 terminals on the top of the capacitor are as follows:
HERM = power to Compressor
COMM = power from the contactor
FAN = power to the fan motor
right?
czadna
Oct 27, 2009, 01:58 PM
Will this work? Or, do I need to do something different with the BRN & BRN/WHT wires?
hvac1000
Oct 27, 2009, 02:06 PM
Do not use old capacitor if you have a new one for the new motor. Just forget the old capacitor exists for fan usage but leave hooked up for compressor usage only.
Then wire brown/white and brown to one wire to each side of the new capacitor you got for the new fan motor.
Then black to one side of contactor and yellow to the other side of contactor since these are the only two wires left.
czadna
Oct 27, 2009, 02:13 PM
Do not use old capacitor if you have a new one for the new motor. Just forget the old capacitor exists for fan usage but leave hooked up for compressor usage only.
Then wire brown/white and brown to one wire to each side of the new capacitor you got for the new fan motor.
Then black to one side of contactor and yellow to the other side of contactor since these are the only two wires left.
Okay,
1st - Let me apologize for any communication errors on my part. I have no experience with these things. I was hoping that the fan motor would be an exact replacement but, there is 1 extra wire now.
2nd - the capacitor IS new. It is identical to the old one (except it is metal- the old one was plastic).
3rd - the capacitor runs BOTH- the compressor & the fan - it is a dual run capacitor, just like the old one.
4th - there are 3 connections (H,C,F) on the top of the capacitor - NOT 2 sides.
It sounds like you are wanting me to use a different capacitor for the Compressor & the Fan. I only have the 1 dual run capacitor.
Stratmando
Oct 27, 2009, 03:24 PM
If the fan is hooked to the cap, I think you can leave connected. Then have the Motor have its own Capacitor, You don't Have to use both of the capacitors in a dual cap. I'm guessing Motor didn't come with Cap, does it show capacitance?
czadna
Oct 27, 2009, 05:09 PM
It's just a motor & it requires a 5µƒ capacitor... the capacitor is a 35/5 dual start capacitor.
czadna
Oct 27, 2009, 05:13 PM
I would think thier would be a small diagram on Motor showing Capacitor and Power connections.
If I was to guess, and I won't, it would be capacitor across the brown and brown/white.
Power to Black and Yellow.
Is the Fan using part of the capacitor? or is it just for Compressor?
The capacitor runs the compressor AND the fan motor.
KISS
Oct 27, 2009, 08:35 PM
Yipes!
AOSmithmotors are in TN (800) 672-6495. Give them a call.
Ask them specifically which capacitor wire Brn or Brn/wht is the same as the Black or the yellow line wire?
Tell them, you cannot find the info on their website. A.O.Smith Electrical Products Company (http://www.aosmithmotors.com)
One of the brn or brn/wht wires you will not be using.
With a good ohmmeter, you should be able to tell as well.
The nameplate may also show it. Can you post a picture of the nameplate?
czadna
Oct 28, 2009, 06:05 AM
What kind of resistance should I be reading for each wire?
KISS
Oct 28, 2009, 10:29 AM
Low, like a few ohms or less. One very low. Lead resistance can be a problem too.
... black yel
Brn
Brn/wht
Fill in the table.
czadna
Oct 28, 2009, 11:00 AM
Is the brn wire with the lowest resistance the winner?
KISS
Oct 28, 2009, 12:40 PM
That's the one to leave out and cap.
czadna
Oct 28, 2009, 12:49 PM
That's the one to leave out and cap.
Thank you so much for your help!
I wish I could afford to reward you for your time.
czadna
Oct 28, 2009, 08:22 PM
I capped the BRN/WHT wire & my a/c is working again. Thank you all for your help!
czadna
Oct 29, 2009, 03:58 PM
FYI: This is what AO Smith said: "To change to a 3-wire hook-up: The brown/white wire and yellow wire are connected together internally. As a result, you need to cap off the brown/white lead and connect the yellow lead to the capacitor. Yellow is the line lead."
KISS
Oct 29, 2009, 04:53 PM
I assumed you didn't own a multimeter. So, you got two ways to solve the same problem. That motor has come up before on AMHD and it was difficult then to get information from AO Smith's website.
Like the old saying goes "More than one way to skin a cat".
czadna
Oct 29, 2009, 06:10 PM
I have a nifty Snap-On tool box that came with a nice multi meter
benconsult
Oct 2, 2010, 09:09 AM
So czadna, I have the same situation: replacing a three wire A.O. Smith with a four wire. Point of clarification: do you mean I should connect yellow to the brown&white, or they are already connected internally, and I should leave brown&while off the wiring, and just use yellow for the power and capacitor like red was in my original installation?
Stratmando
Oct 2, 2010, 09:57 AM
benconsult, did you click on the link czadna showed in his post?
benconsult
Oct 2, 2010, 12:11 PM
Ah! The way my Google search turned up this thread gave me this address, that omits czadna's link:
https://www.askmehelpdesk.com/advice/t-409837.html
Much better now that I have the full info. Thanks!
Stratmando
Oct 2, 2010, 12:43 PM
https://www.askmehelpdesk.com/heating-air-conditioning/c-fan-motor-installation-409837-3.html
Then scroll down to Oct 29, 5:58 PM(czadna's post) and that link has the diagram.