Reply
 
Thread Tools Search this Thread Display Modes
 
Old 09-19-2008, 11:29 AM   #1
Rivet Master
 
funkill's Avatar

 
1973 27' Overlander
reno , NV
Join Date: Aug 2008
Posts: 1,447
Images: 27
confusion with my electrical system

I did a few google searches to try to find some clarification, but the posts I read that came up are confusing me even further. I hope you can bear with me - this is my first trailer and I am not particularly electrically-inclined.

I read some articles on “RV electrical systems” and thought I understood what happened with the converter, inverter, battery and shore power. But I’m definitely missing something. I believed that my 73 Overlander came equipped with a Univolt system that would convert shore 120v to 12v (DC current, right?), except on the A/C & like. And, I thought the Univolt also had a charger to maintain the battery charge. I basically thought the univolt was a converter/charger. Then, an inverter could be used in the 12v plugs to power 120v items (when boondocking and/or on shore power). My thought is that a converter *converts* 120v to 12v and inverter *inverts* 12v to 120v. ….I’m guessing the charger needs 120v to charge the 12v battery.

My Overlander has a deep cycle battery (not sealed) and in the adjacent compartment, an independent converter (purchased by PO) and a fuse panel with about 5 or 6 fuses. I found what I believe is the 120V panel in the bathroom, with two circuit breakers.

After towing her home I secured shore power. Everything seemed to work well – A/C included! Though it cycled in a peculiar way (question for later). I unplugged her for about 2 days, then plugged it back in. Inside the A/S, the 120v house fan, light and radio were working fine. But, when I turned on the three original overhead lights (at the vents) dimmed substantially!!!! There was no change in the 120v items. I noticed the battery showed low on the interior control panel. I figured that, even with a low battery, the 12v overhead vent lights would be unaffected. And I can’t figure out why the battery would have discharged so quickly. I did leave the house table fan, light and radio plugged in while the A/S was disconnected from 120V. Could residual draw from those three items affect the battery so much? Oh, I did notice the A/C buzzing while in the OFF position after I reconnected to shore power. Any idea what is going on?

I asked the PO about steps for recharging the battery using the charger. And I sort of described the problem. His response was that when the A/S was new “she had a charging system like you describe. Somewhere along the line it was removed. I don't recall the 12 volt lights going dimmer when the battery was charging.” Communication error in that I was not charging the battery when the lights dimmed. Sorry this got so long …. sigh.
__________________

__________________
funkill is offline   Reply With Quote
Old 09-19-2008, 11:50 AM   #2
Rivet Master
 
purman's Avatar
 
1968 28' Ambassador
Cedaredge , Colorado
Join Date: Jul 2008
Posts: 2,542
So did the PO say the system was changed?
How new is the battery?

Most don't have inverters in them I could be wrong on this though.. Mine doesn't and neither does my friends 2004 Safari.... Plus you would zap your battery pretty fast going to 120v and plugging something into it.... like a toaster or hair dryer...
And yes you do need shore power to charge your battery, It should also charge while you drive but not very fast...
__________________

__________________
Jason

May you have at least one sunny day, and a soft chair to sit in..

2008 5.7 L V8 Sequoia
AIR # 31243
WBCCI # 6987
FOUR CORNERS UNIT
purman is offline   Reply With Quote
Old 09-19-2008, 12:39 PM   #3
Site Team
 
azflycaster's Avatar
 
1975 25' Tradewind
Dewey , Arizona
Join Date: Mar 2005
Posts: 12,127
Images: 62
Blog Entries: 1
The first thing I would do is check the condition of the battery. Most likely the output of the converter is tied to the battery and the 12 volt systems at the fuse panel. If the battery has an internal short (bad cell) it could pull the output of the converter down to the point where the lights might dim. You could also disconnect the battery and see if the lights work, that would tell you if the converter is working at all.
__________________

Richard

Wally Byam Airstream Club 7513
azflycaster is offline   Reply With Quote
Old 09-19-2008, 04:35 PM   #4
Rivet Master
 
garry's Avatar
 
1969 31' Sovereign
Broken Arrow , Oklahoma
Join Date: Jan 2003
Posts: 1,362
Images: 7
You have it figured out;
Converter= 120VAC to 12VDC

Inverter= 12VDC to 120VAC

When on shore power the converter provides 45/60/80 DC amps depending on the converter. It also charges the battery.

It sounds to me like you may have a battery charger and not a RV converter. Most chargers won't supply the amps a converter provides.

I agree with azflycaster you most likely have a bad battery.

Garry
__________________
garry is offline   Reply With Quote
Old 09-19-2008, 05:23 PM   #5
Ham KI4HJX
 
1982 27' Excella
1970 23' Safari
Franklin , 28734
Join Date: Jul 2007
Posts: 126
The Univolt dose a piss-poor job of charging the battery. Most of the time it melts the battery down (mine killed a brand new Optima gel battery). Best fix is to dump the univolt and buy a new converter that will not kill batteries.
__________________
Ramp is offline   Reply With Quote
Old 09-19-2008, 06:20 PM   #6
Rivet Master
 
funkill's Avatar

 
1973 27' Overlander
reno , NV
Join Date: Aug 2008
Posts: 1,447
Images: 27
The battery is less than 6 months old... but too dark now to check the condition of the cells and see if any are dry. I don't have a way to check the battery myself, but I can get someone to help me with that.

There is definately an individual charger laying in the compartment adjacent to the battery. This same adjacent compartment has a glass fuse panel. The charger is not permanently connected to the battery, but requires me to hook up the clamps for charging.

Would it be reasonable to believe that, since there is no OEM charger, there is no coverter either? I was thinking that all the regular home-style receptacles inside were actually only providing 12v because it was going through a converter --- heck, maybe I'm really getting 120v at those receptacles! I guess it will take a meter to figure this out! Thanks for the help thus far, I will report back with findings soon!
__________________
funkill is offline   Reply With Quote
Old 09-19-2008, 06:52 PM   #7
Site Team
 
azflycaster's Avatar
 
1975 25' Tradewind
Dewey , Arizona
Join Date: Mar 2005
Posts: 12,127
Images: 62
Blog Entries: 1
The home style outlets will be 120 volts ac. A 12 volt DC outlet is round like a auto cigarette lighter. You should have about 3 of these in your trailer. I have 4, but I added one.

Sounds like the PO might have tossed the converter and charged the battery as needed. Not the best solution. Your battery at this point might just need a charge.

Once you determine what you have it will be easy to figure out what you need. Don't worry too much about the original converter being gone, they were not that good to begin with.
__________________

Richard

Wally Byam Airstream Club 7513
azflycaster is offline   Reply With Quote
Old 09-19-2008, 06:57 PM   #8
Rivet Master
 
funkill's Avatar

 
1973 27' Overlander
reno , NV
Join Date: Aug 2008
Posts: 1,447
Images: 27
Pictures of the components

Till I can really look at the parts tomorrow... here's some pics of what I'm working with... I don't know what the univolt system is suppost to look like... but I don't see anything other than the battery, independent charger, and fuse panel. I can't really see what's behind the fuse panel - but that's where I assumed the univolt system was located.
__________________
funkill is offline   Reply With Quote
Old 09-19-2008, 07:03 PM   #9
Got gandkids?
 
Jim & Susan's Avatar

 
1973 27' Overlander
'Possum Holler , Georgia
Join Date: Oct 2004
Posts: 5,406
Images: 39
Looks like a battery charger, not a Univolt. Give me a minute and I'll get a picture of the Univolt and it's proper location. That charger may be frying the battery by constantly charging the battery without ever shutting off.

Jim
__________________
www.nesa.org

Air No. 6427
Jim & Susan is offline   Reply With Quote
Old 09-19-2008, 07:12 PM   #10
Got gandkids?
 
Jim & Susan's Avatar

 
1973 27' Overlander
'Possum Holler , Georgia
Join Date: Oct 2004
Posts: 5,406
Images: 39
Try this again. Messed it up the first time.

The Univolt mounts over the battery box and under the bathtub.

Jim
Attached Thumbnails
Click image for larger version

Name:	Univolt 1.jpg
Views:	106
Size:	128.7 KB
ID:	67712  
__________________
www.nesa.org

Air No. 6427
Jim & Susan is offline   Reply With Quote
Old 09-19-2008, 08:59 PM   #11
Site Team
 
azflycaster's Avatar
 
1975 25' Tradewind
Dewey , Arizona
Join Date: Mar 2005
Posts: 12,127
Images: 62
Blog Entries: 1
The 12 volt distribution panel (fuse block) looks like the original. There should be 2 terminals on the back side that would connect to the converter.
__________________

Richard

Wally Byam Airstream Club 7513
azflycaster is offline   Reply With Quote
Old 09-19-2008, 09:33 PM   #12
Rivet Master
 
Lumatic's Avatar

 
1971 25' Tradewind
1993 34' Excella
Currently Looking...
Estancia , New Mexico
Join Date: Feb 2005
Posts: 6,642
Images: 16
Blog Entries: 1
Quote:
Originally Posted by funkill View Post

After towing her home I secured shore power. Everything seemed to work well ? A/C included! Though it cycled in a peculiar way (question for later). I unplugged her for about 2 days, then plugged it back in. Inside the A/S, the 120v house fan, light and radio were working fine. But, when I turned on the three original overhead lights (at the vents) dimmed substantially!!!! There was no change in the 120v items. I noticed the battery showed low on the interior control panel. I figured that, even with a low battery, the 12v overhead vent lights would be unaffected. And I can?t figure out why the battery would have discharged so quickly. I did leave the house table fan, light and radio plugged in while the A/S was disconnected from 120V. Could residual draw from those three items affect the battery so much? Oh, I did notice the A/C buzzing while in the OFF position after I reconnected to shore power. Any idea what is going on?

I asked the PO about steps for recharging the battery using the charger. And I sort of described the problem. His response was that when the A/S was new ?she had a charging system like you describe. Somewhere along the line it was removed. I don't recall the 12 volt lights going dimmer when the battery was charging.? Communication error in that I was not charging the battery when the lights dimmed. Sorry this got so long ?. sigh.
How old is the battery?
Check the electrolyte level in the battery and have the battery load tested.
Yes those things you describe can drain the battery in a few hours

You've got the general principle down of how the system works.

From what I can see in your photo the original charging sytstem is there, not removed.
__________________
Sail on silver girl. Sail on by. Your time has come to shine.
Lumatic is offline   Reply With Quote
Old 09-20-2008, 05:43 PM   #13
Rivet Master
 
funkill's Avatar

 
1973 27' Overlander
reno , NV
Join Date: Aug 2008
Posts: 1,447
Images: 27
Well, I got into the respective compartments this afternoon and confirmed that there is no univolt system in place. The fuse panel is intact, and the battery is hooked through there... I was able to charge the battery using the independent charger.

Question: should I have any concerns about the current setup? And is there anything else that I need to check? Thanks for your help - this is really making me crazy.
__________________
funkill is offline   Reply With Quote
Old 09-20-2008, 06:34 PM   #14
Site Team
 
azflycaster's Avatar
 
1975 25' Tradewind
Dewey , Arizona
Join Date: Mar 2005
Posts: 12,127
Images: 62
Blog Entries: 1
The setup you have now works, but it is not the best solution. A 3 stage converter will make thing much easier to deal with and your battery will like it too.
__________________

__________________

Richard

Wally Byam Airstream Club 7513
azflycaster 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
Newbie needs help with electrical system jacqueg Batteries, Univolts, Converters & Inverters 7 11-29-2007 05:00 PM
electrical system crowldawg Batteries, Univolts, Converters & Inverters 6 09-27-2007 10:36 AM
'53 Cruiser Electrical System amron Electrical - Systems, Generators, Batteries & Solar 2 02-14-2006 01:49 PM
Electrical System Basics 66 Tradewind Electrical - Systems, Generators, Batteries & Solar 5 10-19-2004 07:24 AM
electrical system 67 tradewind boardsander Electrical - Systems, Generators, Batteries & Solar 3 10-14-2002 05:32 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 06:39 PM.


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.