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rjones1138 05-07-2002 07:11 AM

Univolt Low Buzzing Noise
We're brand new Airstream owners. We just got our 81 Excella 2 set up in the campground. We are noticing a low buzzing noise in the front of the camper. After a long time searching, I figured out that it is coming from the Univolt. The buzzing is constant and low pitched, not very loud. Is this normal? Thanks for the help.

ALANSD 05-07-2002 08:18 AM

When you are plugged in to shore power, there is a low level buzz that is normal from my experience. When I plug in this confirms my connection..and continues all the time I am connected.

Jim W 05-07-2002 11:57 AM

I replaced my univolt a couple of years ago because it stopped working. The new one doesn't make any where near as much noise as the old one did, but you can still hear it. You need to worry when you can't hear it. That was when I had to get a new one.

FrankR 05-07-2002 01:54 PM

Univolt [converter] changes
1 Attachment(s)
Our univolt system is changed from the factory configuration. An aluminium box was fabricated for the univolt. A hole was made to allow the unit to hang from floor under trailer. This location allows more use of floor space, less transformer noise, and the unit operates cooler. The recessed box has a aluminium cover that prevents anything from entering box. The converter is controlled by a standard wall switch near the unit. All the dc voltage used in trailer can be sourced via the converter, the trailer batteries or power from the tow vehicle batteries. The trailer batteries can be used individually or together. The remote location of the converter reduces the output hummmmm considerably. The batteries are connected to a permanently installed digital voltmeter. A fully charged battery will indicate 12.6 on a digital meter. Frank

FrankR 05-07-2002 01:59 PM

Floor mounted converter Pic
1 Attachment(s)
Converter box in floor Frank

tenrsingr 05-07-2002 02:44 PM

I am curious if my post even registered.... Anyway..

Is your new converter an old univolt type or is it a newer solid state type?

tenrsingr 05-07-2002 02:49 PM

Mine is really loud now. I had to buy a fan to drown out the humming...
Do the newer models protect the battery also??


PeterH-350LE 05-07-2002 04:45 PM

1 Attachment(s)
This is a nice little converter.
Inteli-Power 9100 55Amp
The additional charge wizard takes good care of your batteries.
No humming or buzzing, just the occasional cooling fan kicking in.

Jim W 05-07-2002 06:19 PM

I think my new converter is not the replacement univolt. From what I read, it has its own battery charging system that keeps the battery charged, but won't ever over charge it ( they say). When they finished the hook up, there isn't any amps reading on the meter in the control panel, which I liked. I think the unit that Inland RV ( Andy ) has on his web site is a closer to the one that came out of my unit. That unit lasted about 23 years, so I can't complain. The buzzing was louder than the new one & I think the battery charger is much better than the one in the old unit.

Larry Brown 10-29-2002 06:05 PM

Ok? how the ------------ are ya susposed to remove the box that is covered with carpet that covers the univolt I can't seem to find any screws or flanges are anything except for a million staples (furniture type) under the carpet. any ideas would be helpfull.:confused:

PeterH-350LE 10-29-2002 07:06 PM

don't pull all the carpet of the box. It is screwed to the floor and to side via metal flanges. You may have to remove the decorative piece of vinyl to get to the screws.
PM or email me if you wish.

Chas 02-25-2003 07:22 PM

what a deal!
Pulled out ole Mister Buzzy "Univolt" this last weekend and am awaiting my new 60 amp Intelli-Power converter, yes bigger than Peter's, with the "Charge Wizard". I was going to put a switch on it to turn it off so I could sleep but said the heck with it, it will be of better use as a boat anchor. I had an Intelli-Power in my Argosy and they are much quieter, all you hear is a little fan noise occasionally.

By the way, anyone want to guess how much a Univolt weighs? A correct guess will entitle you to a free working Univolt, a little noisy, but servicable. (shipping excluded, of course)


thenewkid64 02-25-2003 07:33 PM


And if I am right I don't want it!!!!!!!!!

Chas 02-25-2003 07:36 PM

Too high, mine is a 55 amp with the internal fuse block and if any of you wanna get closer, heck I'll even spot any of you 5 lbs. either way!

(I edited it and increased it to 5 lbs.)


Chas 02-26-2003 11:12 AM

39 lbs!!
O.K. then,

Newkid is the winner by default!:D

Your address please? I will ship it C.O.D. for the freight.;)


thenewkid64 03-01-2003 10:09 AM


Thanks, but no thanks!

I bet you could get at least $25.00 for it on ebay! Just rememember it is "rare" and "original" and they don't make them like this anymore!:D A new one could cost you 200.00 or more at the local RV dealer!

With tongue firmly planted in cheek................

wb13798 03-01-2003 07:47 PM

i sold one last month for $75.00 . was out of my motor home. replaced it with 9160 with charge wizard.
no thanks i dont want it either.

Chas 03-01-2003 08:42 PM

Ebay? Excellant idea!!,

I actually do have a box where I keep all the outdated and non-working original parts, who knows, someday they may be worth some bucks!! Actually my Airstream dealer kinda wants it for parts, guess it may still have some life in it.

Got the new 60 amp Intelli-Power installed today. Tell me something, my old univolt weighed 39 lbs and the Intelli-Power weighs about 5 lbs., what gives?? Old school, new school?


thenewkid64 03-02-2003 07:16 AM

34 LB weight reduction! cool, now you can carry cases of Adult beverages and never worry if you are in a dry county or not!

startrekker2001 07-04-2003 05:43 AM

Ok, tell me what I am missing here. I see many posts talking about Univolt systems overcharging batteries, so I went to my trusty owners manual for my '78 Excella 500 and read...

"When your Airstream is hooked up to 120 volt A.C. the Univolt System automatically charges the trailer battery and, if it is hooked up, your automobile battery as well. The speed and degree of charge depends on how much power is used for lights and appliances, as only the surplus goes to charging the battery.

... Whenever possible, use the automatic built-in charger of the Univolt System for charging. The charging circuit automatically controls the current, reducing it as the battery increases in charge."

From the sound of this, the Univolt System handles it all. Mine makes a slight buzzing noise, which I understand is normal. Did older Univolt Systems not have a charging circuit that limited the charge?


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