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Chuck 06-06-2002 01:16 PM

What is it? is it a converter, or an inverter? both? does it charge the battery, too?

tenrsingr 06-06-2002 02:29 PM

two fold purpose...
This little puppy is supposed to charge your battery and provide the 12VDC to your rig. Depending on what model you have there are I would image different wiring schemes. This is also the thing you will notice humming at quiet times, or atleast the times its supposed to be quiet. Then all you can hear is this humming sound... Well that would be your univolt, but now if its not humming, you might have a problem. I figure you would have the 12 VDC neccessary to run your lights, fans, or entertainment system. Oh yeah, and your water pump...
Best of luck, cause I sure needed it when I had problems with mine...

ALANSD 06-06-2002 03:56 PM

if you plug into the a/c outlets on your rv without shore power or generator they are useless. The univolt is charging the 12v batteries from the a/c input when plugged in.
I suggest an inverter for using TV or video games or laptops and such if you do not want to run the generator, while off shore line power. You may already have one but if not-
I purchased a nice Jensen inverter with two a/c outlets that rusn my 13" tv and the kids playstation game when travelling without the gen running. It came off ebay and cost half what the store gets- also was new in the box.

Chuck 06-06-2002 04:03 PM

So the outlets in the trailer that look just like houshold 110vAC won't work w/o shore-power? How about the a/c unit? water pump?

FrankR 06-06-2002 06:11 PM

AC DC Electrical systems
Most Airstreams have several kinds of electrical systems. AC is the reference given alternating current that is used in homes and industry. DC is direct current and is associated with battery like electrical. A converter is an electrical divice which converts ac voltage to dc. This is very similar to a battery charger. Old converters were designed to put out a very powerful voltage with little or no regulation. This high voltage with no control would over charge the best batteries and thusly destroy same. A switch is required to control battery charge andto allow converter to be shut off. An inverter is a great electrical device that makes AC from DC. For every AC amp, the batteries must contribute 10 amps DC. A well planned electrical system, can provide an enhanced enjoyment of being on the road. Airstream electrical decisions were made based on finances and cost. Airstreams also have another DC system that is controlled by the tow vehicle.

Action 06-06-2002 07:38 PM

So Frank,
I have a '66 Overlander. I currently do not have a battery in my trailer due to renovations in the back of my trailer. And I still have 12v and 110v devices that work, when plugged in to house current. When I get the plumbing fixed and reinstall the battery, will the univolt overcharge the battery? Or put another way, how well is a 1966 univolt regulated as to battery charging? (Based on your post, do I need to invest in another switch to control overcharging?)

FrankR 06-06-2002 10:18 PM

Up grades to Airstream electrical
There are several areas that need redesign in Airstream trailers. The old univolt will put out some very powerful voltage. Our trailer can produce about 70 amps at 14.7 volts. The univolt will cook and destroy any battery. If the battery has a selector switch to control charging and a voltmeter to monitor condition, the univolt is a valuable asset. There are times that a switch to control the converter is very valuable. The proper care and charging batteries is now a known science. On this same forum there are several other informational posts reguarding AS rewire.
An understood voltmeter is a critical tool for the good maintence of the DC battery system. Yep, it is good to have a AC digital meter also. Just touching a simple push button can reveal the voltage of either the DC or AC system. Many other devices depend on proper voltage values...

Action 06-07-2002 11:26 AM

Thanks for your input Frank.

I can get the meters and wire those in however I am fuzzy on the switch. Are you talking a selector switch to disconnect the battery totally. (I have a switch on my boat to switch between batteries or switch them both off of the system) Or some type of switch to knock down the amps when the battery approaches full charge.

Cause 70 amps is huge! And I didn't realize that the univolt could crank out that kind of current. I have only owned my bullet for a month and a half. And it is my 1st trailer. I have had boats for years. And the charging that my boat gets is when the engine is on at a cruise. I don't slip it.


FrankR 06-07-2002 12:51 PM

Volts, switches and stuff
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I may have mis-spoke. The output for all converters are not the same. There are converters from 30-90 amps. Ya just gotta look at your model. The battery switch is in fact a boat selector switch. Using this switch will allow connection to battery #1 or #2, both or none. While connected to shore power, all 12volt devices can be powered by the converter and NOT charge the batteries. Driving down the road and the trailer batteries do not need any charge, selector switch to off. The dc volt meter should be digital. These meters are available from most solar equiptment stores. An easy way to wire a meter is to use a nice quality push button switch. A fully charged battery will reflect 12.6 volts. A long sloooooo charge is better than a full 90 amp charge. I like to monitor ac voltage too. Gov minimum to us is supposed to be 117 volts ac. Do not use ac volts less than 108 volts ac. RV's and boats are very similar....

FrankR 06-07-2002 12:54 PM

Converter switch too
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Yep, the converter can be turned off as not needed. It tries to use power from the my inverter.......

ALANSD 06-07-2002 01:30 PM

Frank- you must have been on the road...good to have you back posting again on the forums .

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