Another Univolt Question

[kmoore]

I know my 34 year old univolt has seen better days and will need to go, but I was hoping I could make it through the fall camping season before I replace it. My question is: does the Univolt die a a slow death and produce multiple problems/issues or do they usually just quit working all together?



Electrical diagnosis is not my strong suite and the 12v systems are showing signs of having demons within. Various scenarios below....all on 110 shore power, with 110 working great, AC on ect.

• Turn on one two many 12v lights and it will trip a breaker on the 110 panel
• try to use the tounge jack and blows breaker if a light or two is on
• two 12v lights are on and you turn on the third, then one of the other two will go out.....come right back on when you turn that one off again, did not kick the breaker this time.
• Turn on all lights and every 12v appliance and all is fine.... for a while.

Could I have other issues that I am not aware of?

Any thoughts ideas are appreciated!

[Mexray]

Dump the old Univolt! It's past it's prime, and even it it worked properly it will overcharge your batteries if you leave it on, all the time...

Give someone like Randy at Bestconverter.com a call - that's where I got my new solid state, 3-stage converter/charger to replace the Univolt...

the new unit works great and when the batteries are fully charged it goes into 'float' mode at just enough voltage to keep the batteries at full charge...

Ray

[Inland RV Center, In]

Originally Posted by kmoore

I know my 34 year old univolt has seen better days and will need to go, but I was hoping I could make it through the fall camping season before I replace it. My question is: does the Univolt die a a slow death and produce multiple problems/issues or do they usually just quit working all together?



Electrical diagnosis is not my strong suite and the 12v systems are showing signs of having demons within. Various scenarios below....all on 110 shore power, with 110 working great, AC on ect.

• Turn on one two many 12v lights and it will trip a breaker on the 110 panel
• try to use the tounge jack and blows breaker if a light or two is on
• two 12v lights are on and you turn on the third, then one of the other two will go out.....come right back on when you turn that one off again, did not kick the breaker this time.
• Turn on all lights and every 12v appliance and all is fine.... for a while.

Could I have other issues that I am not aware of?

Any thoughts ideas are appreciated!

Sounds like the Univolt is history.

Airstreams current Univolt, is far superior to the original and has been in use for several years with great success.

Andy

[Streamer Dan]

I also have an old univolt in a 89 excella, it makes a really annoying buzzing sound when it's on, but seems to work fine. I really want to change it out for a new (more efficient??), one but wanted to know which the best one is to replace it with, and are the new ones silent, or do they make the buzzing noise as well?

Thanks, Dan

[Inland RV Center, In]

Originally Posted by Streamer Dan

I also have an old univolt in a 89 excella, it makes a really annoying buzzing sound when it's on, but seems to work fine. I really want to change it out for a new (more efficient??), one but wanted to know which the best one is to replace it with, and are the new ones silent, or do they make the buzzing noise as well?

Thanks, Dan

Since your Univolt is only 29 years old, it must not be too bad, except for the buzz.

The buzz is easy to fix.

The buzz is cause by the shellac or varnish that was used to pot the laminations, has give out.

You can remove the transformer, immerse it in a container of varnish or shellac. Move it around every few hours to release any possible bubbles.
Do that to the transformer for 2 to 3 days.

Remove the transformer from the paint, and let it air dry for a few days.

Then reinstall it in your Univolt.

The hum will be "gone".

Costs a lot less than a new charger.

Andy

[Aage]

Dan,
New ones do not buzz.

[sepezlover]

The p.o. of my '74 Sovereign had at some point replaced the original Univolt with a Magna-Tek. It worked just fine until the day it stopped charging the battery...

[68 Overlander]

The older univolts do hum and can be fixed however you are still left with an old Univolt that is one of the most uneffecient power supplies compared to modern switching converters.
Airstream switched to the Parallax 7400 series and then the 7300 series power centers. They will charge your batteries but are not multi stage so if you do any dry camping or otherwise need a fast charge, they are not the answer. Many people also like to store their Airstreams over the winter and again, the single stage of the Parallax is not going to float batteries at a safe level for the winter. Misconception is that they shut off while they do not. You will measure 13.8 volts constantly that will eventually gas/dry your flooded batteries in time.
If you decide to upgrade to a modern converter, consider a multi stage unit such as the Iota or Progressive Dynamics units.