Reply
 
Thread Tools Search this Thread Display Modes
 
Old 06-04-2006, 06:37 PM   #1
Rivet Master
 
Excella CM's Avatar
 
1978 31' Excella 500
Venice , California
Join Date: May 2006
Posts: 1,057
Thumbs up No more Univolt!

I changed out the original Litton Industries converter (Univolt in AS parlance) this week end. It had begun to hum and has always had a tendency to boil the batteries when the trailer is parked for any long period of time. I replaced it with a WFCO 65 amp. unit. Beside being lighter (7# vs 40#) the WFCO has an automatic 3-stage charging regime that is kinder to the batteries. The one problematic difference is that there is no output to the "AC ON" pilot on the control panel to indicate when shore power is connected. I found a simple remedy which is as follows: I found a small 12VAC "wallwart" type plug-in transformer such as is used for many small appliances, etc., and pluged it into the other 110V receptacle where the converter draws its power. I connected one side of the output (doesn't matter which-AC is always changing its mind anyway) to the converter ground lug, and the other side to the pilot light line. Whenever there is 110V power connected, the little transformer lights up the pilot light! Simple, cheap, and effective-no brainer solution.
__________________

__________________
"Not all who are laundering are washed" say Bill & Heidi

'78 Excella 500,"The Silver Pullit". vacuum over hydraulic disc brakes, center bath, rear twin. '67 Travelall 1200 B 4X4 WBCCI 3737
Excella CM is offline   Reply With Quote
Old 06-05-2006, 12:20 AM   #2
Rivet Master
 
bhayden's Avatar
 
1978 24' Argosy 24
Woodinville , Washington
Join Date: May 2006
Posts: 646
Images: 10
>>> I connected one side of the output (doesn't matter which-AC is always changing its mind anyway)

Uh, yes it does. One leg should be "hot". That is a sine wave oscilating from + to -. Half the rated voltage if it's full wave recified. The other pole is return which should be at the same potetial as ground.

If the bulb on the panel is rated for DC then you're essentially turning it on and off either 60 or 120 times a second depending on if it's full or half wave rectified and assuming it's 60Hz. A 12 DC bulb won't hold up to this for very long.
__________________

__________________
bhayden is offline   Reply With Quote
Old 06-05-2006, 02:33 AM   #3
VAC President
 
Buttercup's Avatar
 
1977 27' Overlander
1954 25' Cruiser
1990 34.5' Airstream 345
VC Highlands , Nevada
Join Date: Mar 2005
Posts: 2,141
Send a message via Skype™ to Buttercup
I may be mistaken but wasn't the "AC ON" pilot light supplied A.C. power anyway from a tertiary winding on the Univolt? I don't have a schematic for the univolt and have never seen one but that is the impression I had.

I can look into this as I still have my old unit sitting around. I could take it apart and see what is what...
__________________
Buttercup's Web Site. WBCCI #17330, 11281 & 7830. VAC Past President & Webmaster, TAC NV-2 & NV-3.
2014 Mouse count: Buttercup - 0 / Airtini -
Buttercup is offline   Reply With Quote
Old 06-05-2006, 12:31 PM   #4
Rivet Master
 
Excella CM's Avatar
 
1978 31' Excella 500
Venice , California
Join Date: May 2006
Posts: 1,057
My Univolt was a Litton Industries unit with two low voltage windings. the telltale line for the pilot was connected one of them on the upstream side of the rectifier. The output for the telltale was 12 VAC. This is why I used an AC wall-wart. I suppose you could use a 12VDC wallwart and run the hot side to the bulb. Six to one, a half-dozen to the other?
__________________
"Not all who are laundering are washed" say Bill & Heidi

'78 Excella 500,"The Silver Pullit". vacuum over hydraulic disc brakes, center bath, rear twin. '67 Travelall 1200 B 4X4 WBCCI 3737
Excella CM is offline   Reply With Quote
Old 06-05-2006, 04:54 PM   #5
uwe
418
 
uwe's Avatar
 
1963 26' Overlander
1958 22' Flying Cloud
1963 19' Globetrotter
Portola Hills , California
Join Date: Jun 2002
Location: 1963 26' Overlander
Posts: 4,764
Images: 41
Send a message via Skype™ to uwe
Quote:
Originally Posted by Excella CM
I suppose you could use a 12VDC wallwart and run the hot side to the bulb. Six to one, a half-dozen to the other?
More like 12 to one, two sixes to the other.....
It does not matter. Lamps don't care if it is A/C or D/C, so long that the nominal voltage stays around 12V. Different story altogether with electric motors.
__________________
Uwe
www.area63productions.com
uwe is offline   Reply With Quote
Old 08-02-2007, 03:05 PM   #6
2 Rivet Member
 
1979 31' Excella 500
Battle Mountain , Nevada
Join Date: Aug 2006
Posts: 36
Images: 3
Send a message via Yahoo to mikeandbecky
So, which is it? Would it destroy the AC ON lamp in the display panel it a + AC line was hooked up to it. I have the grey wire dangling because I have also removed the Univolt, and (soon) will be replacing it with a WFCO 3 stage converter. Or, maybe Ill leave it dangle, and go with Excella CM's idea with the " wallwart ".
__________________
mikeandbecky is offline   Reply With Quote
Old 08-02-2007, 03:34 PM   #7
3 Rivet Member
 
AirConditioner's Avatar
 
Join Date: Jul 2004
Posts: 146
This might be of help to you from the "Best Converter" site"

http://www.bestconverter.com/assets/...t/Univoltp.pdf
__________________
AirConditioner is offline   Reply With Quote
Old 08-02-2007, 03:55 PM   #8
Rivet Master
 
Excella CM's Avatar
 
1978 31' Excella 500
Venice , California
Join Date: May 2006
Posts: 1,057
The "dangling" grey wire is the feed to the "AC" on light on your control panel. Modern converters do not have a tap for this so you have to work around it. The wallwart is simple if you use a 12VAC type. Just connect the 110 VAC side of it where the converter gets power(if you have a duplex box, just plug it in) and run one side of the 12 VAC output to ground (you can use the one on the converter) and the other to the left over dangler. When the converter gets power so does the wallwart and the AC pilot will light.
__________________

__________________
"Not all who are laundering are washed" say Bill & Heidi

'78 Excella 500,"The Silver Pullit". vacuum over hydraulic disc brakes, center bath, rear twin. '67 Travelall 1200 B 4X4 WBCCI 3737
Excella CM 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
Univolt FACTS smily Electrical - Systems, Generators, Batteries & Solar 69 08-18-2005 11:47 PM
1981 Airstream Excella Univolt dienst1 Airstream Motorhome Forums 1 08-20-2002 09:05 AM
Bad Univolt? pebblepoint Batteries, Univolts, Converters & Inverters 1 07-14-2002 10:08 PM
univolt III wiring McGill Electrical - Systems, Generators, Batteries & Solar 0 07-05-2002 08:26 PM
Univolt Operation melprice Electrical - Systems, Generators, Batteries & Solar 11 06-17-2002 04:13 PM




Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

RV & Travel Trailer Communities

Our RV & Travel Trailer sites encompasses virtually all types of Recreational Vehicles, from brand-specific to general RV communities.

» More about our RV Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


Copyright 2002-2012 Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 05:49 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.

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

Airstream News Delivered to your Email!

Stay up-to-date with Airstream news in your inbox!

unsusbcribe at anytime with one click

Close [X]