Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-18-2010, 04:54 PM   #1
2 Rivet Member
 
BossCamper's Avatar
 
1973 25' Tradewind
Chatham , Ontario
Join Date: Sep 2009
Posts: 84
Armstrong TR 21-12 running amperage

Does anyone know what the specs are for an Armstrong TR 21-12 A/C?

My old unit seemed to run good for a time, but now it has started tripping the breaker in the house.
I checked it today and found that the compressor ALONE, is drawing 12 to 13 amps, then increasing after 5 minutes, or so, to 15 to 16 amps. On a 15 amp breaker ... no wonder it is tripping the breaker!

Does anyone know what that unit should draw?

And what would be the reasons it has started drawing more?

I have thought about maybe too much head pressure from maybe the freon in it being dirty from scales in the lines after sitting for 15 years or so, not running. But I don't know if this is even a valid idea.

I've been happy thinking I won't have to get a new A/C, but now I'm not so sure!

Any insights?

Thanks in advance
__________________

__________________
Airstream Project Picture Gallery
http://lorisart.org/gallery/thumbnails.php?album=34
BossCamper is offline   Reply With Quote
Old 07-18-2010, 05:52 PM   #2
Rivet Master
Airstream Dealer
 
Inland RV Center, In's Avatar
 
Corona , California
Join Date: Feb 2002
Posts: 16,499
Images: 1
Quote:
Originally Posted by BossCamper View Post
Does anyone know what the specs are for an Armstrong TR 21-12 A/C?

My old unit seemed to run good for a time, but now it has started tripping the breaker in the house.
I checked it today and found that the compressor ALONE, is drawing 12 to 13 amps, then increasing after 5 minutes, or so, to 15 to 16 amps. On a 15 amp breaker ... no wonder it is tripping the breaker!

Does anyone know what that unit should draw?

And what would be the reasons it has started drawing more?

I have thought about maybe too much head pressure from maybe the freon in it being dirty from scales in the lines after sitting for 15 years or so, not running. But I don't know if this is even a valid idea.

I've been happy thinking I won't have to get a new A/C, but now I'm not so sure!

Any insights?

Thanks in advance
A poor extension cord, can cause the problem

A low Freon level can cause the problem.

A dirty condenser coil, can cause the problem.

Internal trash in the freon lines? About 10 million to one, "NO".

The current draw increases, as the ambient temperature increases.

A 15 amp breaker, is not adequate. A 20 amp is specified by Airstream.

What is the temperature differential of the air immediately at the AC intake and exhaust? It should be, after a few minutes, 15 to 18 degrees.

Andy
__________________

__________________
Inland RV Center, In is offline   Reply With Quote
Old 07-18-2010, 06:25 PM   #3
2 Rivet Member
 
BossCamper's Avatar
 
1973 25' Tradewind
Chatham , Ontario
Join Date: Sep 2009
Posts: 84
I forgot ... the voltage at the trailer is 117 volts.
__________________
Airstream Project Picture Gallery
http://lorisart.org/gallery/thumbnails.php?album=34
BossCamper is offline   Reply With Quote
Old 07-18-2010, 06:42 PM   #4
Rivet Master
Airstream Dealer
 
Inland RV Center, In's Avatar
 
Corona , California
Join Date: Feb 2002
Posts: 16,499
Images: 1
Quote:
Originally Posted by BossCamper View Post
I forgot ... the voltage at the trailer is 117 volts.
What is the voltage at the trailer, with the AC off, and then running?

Andy
__________________
Inland RV Center, In is offline   Reply With Quote
Old 07-18-2010, 06:52 PM   #5
2 Rivet Member
 
BossCamper's Avatar
 
1973 25' Tradewind
Chatham , Ontario
Join Date: Sep 2009
Posts: 84
Quote:
Originally Posted by Inland RV Center, In View Post
A poor extension cord, can cause the problem

A low Freon level can cause the problem.

A dirty condenser coil, can cause the problem.

Internal trash in the freon lines? About 10 million to one, "NO".

The current draw increases, as the ambient temperature increases.

A 15 amp breaker, is not adequate. A 20 amp is specified by Airstream.

What is the temperature differential of the air immediately at the AC intake and exhaust? It should be, after a few minutes, 15 to 18 degrees.

Andy
Thanks for the insights.

My extension cored is adequate.

The coils are clean, although I am considering getting a cleaner for AC condenser fins that will clean the oxidation off them. I'll have to get someone to check the freon levels. They could very well be low considering the age of the thing. On the AC in the inside it says 20 amp breaker maximum. the breaker box in the trailer has a 15 amp in it for that line.

I haven't measured the temp differential, but while it is running (sometimes for hours) it has to be at least 15 to 18 degrees, or even more!

Best guess so far is the freon levels. And I bet it is freon. I'll likely have to get it changed over to the newer refrigerant if I get a tech to look at it.
__________________
Airstream Project Picture Gallery
http://lorisart.org/gallery/thumbnails.php?album=34
BossCamper is offline   Reply With Quote
Old 07-18-2010, 07:01 PM   #6
2 Rivet Member
 
BossCamper's Avatar
 
1973 25' Tradewind
Chatham , Ontario
Join Date: Sep 2009
Posts: 84
Quote:
Originally Posted by Inland RV Center, In View Post
What is the voltage at the trailer, with the AC off, and then running?

Andy
I didn't think of checking that ... With the AC off, it is 116.7 volts When I turn it on it drops to 102 volts!!
Not even close to being enough!
I'll have to look closer at my connection.
__________________
Airstream Project Picture Gallery
http://lorisart.org/gallery/thumbnails.php?album=34
BossCamper is offline   Reply With Quote
Old 07-18-2010, 08:09 PM   #7
Rivet Master
Airstream Dealer
 
Inland RV Center, In's Avatar
 
Corona , California
Join Date: Feb 2002
Posts: 16,499
Images: 1
Quote:
Originally Posted by BossCamper View Post
I didn't think of checking that ... With the AC off, it is 116.7 volts When I turn it on it drops to 102 volts!!
Not even close to being enough!
I'll have to look closer at my connection.
Or, the size wire in the extension cord.

A "good" and proper extension cord, would not have that voltage drop.

As an example, a good 25 to 50 foot extension cord should be about 8 gauge, or better.

Andy
__________________
Inland RV Center, In is offline   Reply With Quote
Old 07-18-2010, 09:56 PM   #8
Wise Elder
 
Jammer's Avatar
 
2010 30' Classic
Vintage Kin Owner
South of the river , Minnesota
Join Date: Dec 2009
Posts: 4,119
Low freon levels lead to low amp draw.

Unlike automotive air conditioning systems, it is rare for older air conditioners to develop leaks or to lose refrigerant slowly over time.

Be sure you've checked the condition of the condenser carefully and be sure that there's good airflow across it.
__________________
Jammer is offline   Reply With Quote
Old 07-18-2010, 10:48 PM   #9
4 Rivet Member
 
Distantdrummer's Avatar
 
1975 31' Sovereign
Houston , Texas
Join Date: Nov 2003
Posts: 494
Arrow Later model manual might help, might not.

Here is a thread link that has the manual for the TR-25-12 . (go to post #5 in the thread).
http://www.airforums.com/forums/f427...ase-52973.html
You probably have already seen it, but if not maybe something in the manual will add to your knowledge.
I have yet to find a manual for the TR-21-12 on the forums or any where else for that matter. It is sorely missed and much needed on these forums if anyone could scan & post the TR-21-12 or any other Armstrong manuals or data sheets.
__________________
__________________________
____ d'drummer ____

...aahh..rumm..pu..tum..tummm...
Distantdrummer is offline   Reply With Quote
Old 07-19-2010, 04:25 AM   #10
2 Rivet Member
 
BossCamper's Avatar
 
1973 25' Tradewind
Chatham , Ontario
Join Date: Sep 2009
Posts: 84
Thanks for the manual. I hadn't seen it, so it will surely help.
__________________
Airstream Project Picture Gallery
http://lorisart.org/gallery/thumbnails.php?album=34
BossCamper is offline   Reply With Quote
Old 07-19-2010, 08:32 PM   #11
2 Rivet Member
 
BossCamper's Avatar
 
1973 25' Tradewind
Chatham , Ontario
Join Date: Sep 2009
Posts: 84
Well, I've tried a couple of things. I have a SOB as well, so I connected it to the same cord plugged into the same outlet at the house and checked the voltage and it only showed minimal voltage drop between nothing on, and the AC running full, so I know it isn't my power connection. The cord is a regular RV 30 amp power cord, so I was certain it wasn't at fault.
Seems like the old thing is just drawing too much power
I have a nephew that is a refrigeration service tech for a local company. They do commercial stuff, but he should be able to figure something out for me. I think I'll impose on him and get some advice/repairs/whatever. I don't like calling on relatives and taking advantage, but what the heck!
__________________
Airstream Project Picture Gallery
http://lorisart.org/gallery/thumbnails.php?album=34
BossCamper is offline   Reply With Quote
Old 11-11-2010, 12:23 PM   #12
2 Rivet Member
 
Mulligan's Avatar
 
1973 27' Overlander
Vintage Kin Owner
kettering , northants
Join Date: Aug 2010
Posts: 90
Quote:
Originally Posted by Distantdrummer View Post
Here is a thread link that has the manual for the TR-25-12 . (go to post #5 in the thread).
http://www.airforums.com/forums/f427...ase-52973.html
You probably have already seen it, but if not maybe something in the manual will add to your knowledge.
I have yet to find a manual for the TR-21-12 on the forums or any where else for that matter. It is sorely missed and much needed on these forums if anyone could scan & post the TR-21-12 or any other Armstrong manuals or data sheets.
Hi, My 73 overlander has an Armstrong 21-12 fitted and although the service manual does'nt actually say 21-12 all the pictures look exactly like my A/C i'll happily scan and post online if it will help you. Tim
__________________
Mulligan is offline   Reply With Quote
Old 11-11-2010, 01:42 PM   #13
Rivet Master
 
1977 Argosy 24
Currently Looking...
Milltown , Wisconsin
Join Date: Mar 2006
Posts: 1,069
Quote:
Originally Posted by BossCamper View Post
I didn't think of checking that ... With the AC off, it is 116.7 volts When I turn it on it drops to 102 volts!!
Not even close to being enough!
I'll have to look closer at my connection.
You should still have 117 volts with it running if the extension cord was up to it's job. Before you spend a lot of time and $ why not try a heavier gauge cord as short as possible to get from the camper to the house outlet. The longer it is the more voltage drop you get.
__________________
ventport is offline   Reply With Quote
Old 11-11-2010, 04:14 PM   #14
2 Rivet Member
 
BossCamper's Avatar
 
1973 25' Tradewind
Chatham , Ontario
Join Date: Sep 2009
Posts: 84
Thanks for the advice.
I understand all that, and am my own worst enemy. The trailer is on blocks and can't be moved closer. I was using the 30 amp extension cords with a cheater adapter to plug into the 15 amp circuit in the house. I am embarrassed to say I had 5 25' cords! And to make matters worse, I had the polarity reversed!

I'm gonna wait till I get it back on wheels and move it closer and maybe even rig up a 30 amp circuit and test it properly.
I don't think there is anything wrong with the AC.

Thanks again

Loris
__________________

__________________
Airstream Project Picture Gallery
http://lorisart.org/gallery/thumbnails.php?album=34
BossCamper is offline   Reply With Quote
Reply


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
Heater Amperage 85Sovereign Furnaces, Heaters, Fireplaces & Air Conditioning 35 02-20-2007 08:14 AM
armstrong a/c mike beech Furnaces, Heaters, Fireplaces & Air Conditioning 16 01-06-2007 06:31 PM
Water Pump - Fuse Amperage??? TroutStream Water Heaters, Filters & Pumps 1 12-03-2004 07:50 AM
Tag Axel Brake Voltage / Amperage 87MH Mechanics Corner - Engines, Transmission & More... 1 11-11-2003 10:25 AM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 06:30 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.