Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > RV SYSTEMS AND TECHNOLOGIES FORUMS > RV Systems & Appliances
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 08-01-2022, 05:32 PM   #1
Junior Member
 
Join Date: Jul 2022
Location: Wherever The Road Leads Me
Posts: 6
Carrier AirV Fan Motor Replacement - Need guidance on wiring!

I’m replacing the original fan motor in a Carrier AirV roof unit. I purchased the replacement motor from Grainger, Item # 4UU28, and it is a near perfect match. I say near perfect because the motor body is overall shorter and it has a capacitor already built on.

I’ve attached pictures of both the OEM and replacement motors’ dataplates and wiring diagrams.

The OEM unit has a three-input, dual capacitor 12.0. The new motor has a two-input, single capacitor 5.0.

The OEM motor has four wires.
Black (High) - Coming from inside panel
Blue (Low) - Coming from inside panel
Brown (Fan) - Coming from capacitor
White (Common) - Coming from capacitor

The new motor has only three wires.
Black (High)
Red (Low)
Yellow (Line)

I know I need to make the following connections to the new motor: Black - Black and Blue - Red. However, I’m unsure as to what I need to connect to Yellow. Also, if I’m to connect to either Brown (Fan) or White (Common), then should I tap into them before they connect to the OEM capacitor?

I have the new motor installed. I just need some confirmation/guidance on the wiring before I energize it. Any help is greatly appreciated. Thank you!

Justin
Attached Thumbnails
Click image for larger version

Name:	OEM Motor Dataplate.jpg
Views:	10
Size:	212.1 KB
ID:	372588   Click image for larger version

Name:	OEM Motor Wiring Diagram.png
Views:	10
Size:	62.6 KB
ID:	372589  

Click image for larger version

Name:	Replacement Motor.jpg
Views:	7
Size:	226.9 KB
ID:	372590   Click image for larger version

Name:	Replacement Motor Dataplate.JPEG
Views:	11
Size:	331.2 KB
ID:	372591  

Justin Alias is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 08-02-2022, 06:42 AM   #2
Senior Member
 
Join Date: Aug 2019
Location: Eastern outskirts of Dallas, TX
Posts: 2,131
Yellow is the neutral aka white from the original motor going to the common terminal on the capacitor.

The brown going to the dual capacitor is no longer used. That terminal will remain unconnected on the dual cap.
__________________
‘91 Ultrastar Champion‘02 Georgie Boy Landau 8.1l Workhorse
‘03 Jeep Wrangler TJ 2018 Jeep Wrangler JK toad
MrMark52 is offline   Reply With Quote
Old 08-02-2022, 12:14 PM   #3
Junior Member
 
Join Date: Jul 2022
Location: Wherever The Road Leads Me
Posts: 6
Thank you for your reply and the help on wiring. It was a quick and simple connect since it was already installed. Everything is working fine now. Now a nice break from the 100 degree temperatures.
Justin Alias is offline   Reply With Quote
Old 08-02-2022, 01:20 PM   #4
Senior Member
 
Join Date: Aug 2019
Location: Eastern outskirts of Dallas, TX
Posts: 2,131
Thanks for reporting back!
__________________
‘91 Ultrastar Champion‘02 Georgie Boy Landau 8.1l Workhorse
‘03 Jeep Wrangler TJ 2018 Jeep Wrangler JK toad
MrMark52 is offline   Reply With Quote
Old 08-10-2022, 12:09 PM   #5
Junior Member
 
Join Date: Jul 2022
Location: Wherever The Road Leads Me
Posts: 6
Exclamation Need Help With Another Issue

*UPDATE*

Just a week after the replacement fan motor was installed, the unit is having more issues. When I turn on the unit the fan starts fine, and much quieter than the OEM motor. However, when the compressor kicks in, it runs for about 5 minutes and blows cold air, but then it makes a clunking sound and trips the breaker. I think it is overheating because it is extremely hot to touch. The reason why I replaced the OEM fan motor is because it just stopped working. Could this have affected the compressor?
__________________
2003 Keystone Outback 25RSS
2013 Chevrolet Suburban LT 4WD
Justin Alias is offline   Reply With Quote
Old 08-10-2022, 01:54 PM   #6
Senior Member
 
Join Date: Aug 2019
Location: Eastern outskirts of Dallas, TX
Posts: 2,131
Could have.

These particular compressors are designed differently than most A/C compressors. The shell of the compressor see’s hot discharge gas - as opposed to most A/C compressors that see’s cool return suction gas. So it will get hot.
They are also known as a rotory vane compressor as opposed to a reciprocating compressor.

I would be concerned with the clunking sound. But clunking could be due to electrical issues where power is intermittently making/breaking as a marginal connection heats up.

Check all the compressor wiring connections - check at the run caps, pull the electrical cover off the compressor and check the 3 wire connections there. Look at the run cap for signs of swelling. Check the connections at the PTC hard start device (I’ve had them that looked good, but as soon as I grabbed them, they fell apart in my hand).

If you have an ammeter, monitor the compressor current for the 5 minute duration. It should spike high while the compressor starts, then drop to somewhere around the indicated FLA and remain fairly steady throughout.

Not much inside a rotory compressor that can go “clunk” - and any clunking in a reciprocating compressor (which is somewhat built like a car engine) would generally prevent subsequent “cooling capable” operation.
__________________
‘91 Ultrastar Champion‘02 Georgie Boy Landau 8.1l Workhorse
‘03 Jeep Wrangler TJ 2018 Jeep Wrangler JK toad
MrMark52 is offline   Reply With Quote
Old 08-10-2022, 02:49 PM   #7
Junior Member
 
Join Date: Jul 2022
Location: Wherever The Road Leads Me
Posts: 6
Thank your again for your reply and guidance. I'll look into everything you suggested and report back my findings.
__________________
2003 Keystone Outback 25RSS
2013 Chevrolet Suburban LT 4WD
Justin Alias is offline   Reply With Quote
Old 08-11-2022, 06:12 PM   #8
Senior Member
 
Ford Super Duty Owner
Join Date: May 2006
Location: Near St Louis, MO
Posts: 354
The correct name is "scroll compressor" You can bush up on them at this site: https://www.hvacrcompressor.com/hvac...oll-compressor
Nothing goes back and forth in them. Compressing the gas is done in one continuous motion at very close tolerances.

As you've guessed, that noise a sign of major problems. Are you sure the noise is coming from the compressor? Does the fan continue to run when the noise starts?
DFord is offline   Reply With Quote
Old 08-11-2022, 06:25 PM   #9
Senior Member
 
Join Date: Aug 2019
Location: Eastern outskirts of Dallas, TX
Posts: 2,131
Quote:
Originally Posted by DFord View Post
The correct name is "scroll compressor" You can bush up on them at this site: https://www.hvacrcompressor.com/hvac...oll-compressor
Nothing goes back and forth in them. Compressing the gas is done in one continuous motion at very close tolerances.

As you've guessed, that noise a sign of major problems. Are you sure the noise is coming from the compressor? Does the fan continue to run when the noise starts?
I’ve not see a scroll compressor used in a MoHo unit.

Rotary - yes. Here is an example -https://na.industrial.panasonic.com/products/hvacr-appliance-devices/air-conditioning-compressors/lineup/rotary-compressors

You are correct as to how a scroll works relative to close tolerances.
__________________
‘91 Ultrastar Champion‘02 Georgie Boy Landau 8.1l Workhorse
‘03 Jeep Wrangler TJ 2018 Jeep Wrangler JK toad
MrMark52 is offline   Reply With Quote
Old 08-11-2022, 08:51 PM   #10
Junior Member
 
Join Date: Jul 2022
Location: Wherever The Road Leads Me
Posts: 6
No, I am not certain that the noise is coming from the compressor. I just assumed it was the compressor because it only occurs when the compressor is running. If I set the thermostat at a higher temperature to prevent the compressor from kicking in then the fan runs fine. When the noise occurs the fan does keep blowing. But shortly after, the breaker trips shutting everything off.
__________________
2003 Keystone Outback 25RSS
2013 Chevrolet Suburban LT 4WD
Justin Alias is offline   Reply With Quote
Old 08-11-2022, 09:12 PM   #11
Senior Member
 
Ford Super Duty Owner
Join Date: May 2006
Location: Near St Louis, MO
Posts: 354
Quote:
Originally Posted by Justin Alias View Post
No, I am not certain that the noise is coming from the compressor. I just assumed it was the compressor because it only occurs when the compressor is running. If I set the thermostat at a higher temperature to prevent the compressor from kicking in then the fan runs fine. When the noise occurs the fan does keep blowing. But shortly after, the breaker trips shutting everything off.
So the new fan is quieter. Are you sure it's turning the right direction? A double shaft motor could be installed either way.

You say it runs a few minutes before the noise starts. One thing is common to all compressor styles - they become liquid pumps a split second before they become junk. You can't compress a liquid.

If the fan is turning the wrong way and not blowing enough air through the coil, the refrigerant may not be boiling off completely in the evaporator. If liquid refrigerant is getting back to the compressor, I can imagine it making a lot of noise just before the liquid jams the rotor stopping it and tripping the breaker. If the problem was an electrical problem with the compressor, I doubt if it would start/run again without tripping the breaker right away.
DFord is offline   Reply With Quote
Old 08-11-2022, 09:21 PM   #12
Junior Member
 
Join Date: Jul 2022
Location: Wherever The Road Leads Me
Posts: 6
Quote:
Originally Posted by DFord View Post
So the new fan is quieter. Are you sure it's turning the right direction? A double shaft motor could be installed either way.

You say it runs a few minutes before the noise starts. One thing is common to all compressor styles - they become liquid pumps a split second before they become junk. You can't compress a liquid.

If the fan is turning the wrong way and not blowing enough air through the coil, the refrigerant may not be boiling off completely in the evaporator. If liquid refrigerant is getting back to the compressor, I can imagine it making a lot of noise just before the liquid jams the rotor stopping it and tripping the breaker. If the problem was an electrical problem with the compressor, I doubt if it would start/run again without tripping the breaker right away.
Yes, the fan is turning the right way. Before I put the unit back together, I made sure to run a fin comb through the coil and thoroughly cleaned it with foam coil cleaner. From the sound of what you’re saying I may not waste any more time and money on an old unit. It may be more beneficial overall to just replace the entire thing.
Justin Alias is offline   Reply With Quote
Old 08-12-2022, 03:30 AM   #13
Senior Member
 
Join Date: Aug 2019
Location: Eastern outskirts of Dallas, TX
Posts: 2,131
Usually difficult to put these motors in backwards because one shaft is shorter than the other.

But even if installed backwards, it wouldn’t trip the breaker the moment the compressor is told to cycle on.

You need to check all the wiring for the compressor, including the 3 wires as they connect in the inside of the compressor enclosure.

In other words, follow/complete the suggestions given in post #6.
__________________
‘91 Ultrastar Champion‘02 Georgie Boy Landau 8.1l Workhorse
‘03 Jeep Wrangler TJ 2018 Jeep Wrangler JK toad
MrMark52 is offline   Reply With Quote
Old 08-12-2022, 08:51 AM   #14
Senior Member
 
Ford Super Duty Owner
Join Date: May 2006
Location: Near St Louis, MO
Posts: 354
Quote:
Originally Posted by Justin Alias View Post

When I turn on the unit the fan starts fine, and much quieter than the OEM motor. However, when the compressor kicks in, it runs for about 5 minutes and blows cold air, but then it makes a clunking sound and trips the breaker.

Quote:
Originally Posted by MrMark52 View Post


it wouldn’t trip the breaker the moment the compressor is told to cycle on.
OP says the compressor runs for about 5 minutes before it gets noisy and trips the breaker. That's what led me to think it was liquid finding it's way back to the compressor.


(I've had many double shaft replacement motors that had equal length extra long shafts that had to be cut to length on the job.)
DFord is offline   Reply With Quote
Reply

Tags
ace, air, fan, motor, replace, replacement, wiring



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Recommendation on someone to repair Carrier AirV in NE quadrant? blang Class A Motorhome Discussions 8 08-12-2016 04:28 PM
Carrier AirV Replacment Capacitor Tjuchcinski RV Systems & Appliances 2 02-23-2016 06:00 AM
Carrier AirV low profile upper unit wildhorse RV Systems & Appliances 3 10-07-2014 04:00 PM
advice regarding our Carrier Airv unit Folkestone Damon 9 09-18-2012 09:21 AM
carrier airv driving me nuts!!!!! please help BM66040 Travel Trailer Discussion 2 05-08-2012 09:43 AM

» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 10:17 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2022, vBulletin Solutions, Inc.