Change out of Univolt

[stephenh2]

Well I pretty much completed the upgrade to my new Inteli-Power 7200 yesterday. I also took the time to repair the battery box, which was in poor shape due to the entire weight of the old Univolt resting on top of it with support only on one end.

The door to the battery box still doesn't close as well as I would like, partially due to the fact that the PO replaced the latch bar with something completely inadequate. He put a flimsy metal bar there that bends with only a moderate amount of pressure applied to it. I need to find a replacement for the bar, so if anyone has one laying around, I would be glad to make a deal for it.

Photos of the upgrade:











I closed off the "new" converter compartment with 1/4" plywood, leaving ample air flow top and bottom. The framework for the opening stiffened up the panel sufficiently for me to feel good about the horizontal mounting arrangement.

Stephen

[Inland RV Center, In]

Originally Posted by stephenh2

Well I pretty much completed the upgrade to my new Inteli-Power 7200 yesterday. I also took the time to repair the battery box, which was in poor shape due to the entire weight of the old Univolt resting on top of it with support only on one end.

The door to the battery box still doesn't close as well as I would like, partially due to the fact that the PO replaced the latch bar with something completely inadequate. He put a flimsy metal bar there that bends with only a moderate amount of pressure applied to it. I need to find a replacement for the bar, so if anyone has one laying around, I would be glad to make a deal for it.


I closed off the "new" converter compartment with 1/4" plywood, leaving ample air flow top and bottom. The framework for the opening stiffened up the panel sufficiently for me to feel good about the horizontal mounting arrangement.

Stephen

Looks great.

Andy

[Zeppelinium]

Don't throw away the fuse block inside the Univolt. It has the current measuring shunt on it.

Zep

[Aviator]

Zep,

What is the current measuring shunt still needed for? Isn't there on integral with the Intelli-Power and similar systems? (Please pardon my ignorance, I understand DC systems and T/R's, but the Airstream setup is new/unfamiliar to me.)

[Zeppelinium]

Originally Posted by Aviator

...What is the current measuring shunt still needed for? Isn't there on integral with the Intelli-Power and similar systems? ...

The IntelliPower has auto current limiting and shutdown. It does not have an output that tells you what the current is, real time.

The shunt is an approximately 0.001 ohm resistor. You put it in the battery's negative (ground lead). In the ground lead, both of the sensing wires are never more than 50 millivolts above ground--it's a nice safety approach. You will find three small gauge wires back where the Univolt was and you now don't know what they did. One of them was tied directly to the positive side of the batter and reported total battery voltage. The other two were attached across the shunt and reported amps in millivolts/amp (one millivolt equalled one amp). The 1975 and later models had a mechanical voltmeter and millivoltmeter in the control panel, but they were inaccurate, to say the least. Sort of a green-yellow-red scale. See an alternative here. If you read the whole thread, for $50 you get an electrical engineering degree.

Zep

[2xS]

Originally Posted by stephenh2

I need to find a replacement for the bar, so if anyone has one laying around...

I used an 2" x 3/8" steel plate cut to length for this job; I drilled and riveted a new piano hinge to the door and to the plate, then I riveted the plate to the trailer. It's looks lovely and is solid.

Getting rid of that Univolt was one of the first things I did; mine was installed under the bathtub that was disintegrating!

When it comes down to it:
Univolt = any fuse block + any 12V power supply/charger


@Zep - You assume the control panel still functions or that someone (without an electronics degree) could fix it!

[Zeppelinium]

Originally Posted by 2xS

...Zep - You assume the control panel still functions or that someone (without an electronics degree) could fix it!

Ah, ha! Everyone could have a working control panel (or at least working tank level monitors) if they got on the band wagon and made a group purchase of the circuit board and panel linked above.

Zep

[Aviator]

Thanks, Zep.

[2xS]

Zep,

I had been eying your offer on that for a while, as well as your research on the replacement. I would have taken you up on it if it wasn't for some fancy bells and whistles I would like to integrate like ALL digital indoor/outdoor temperature, propane tank levels, battery voltage and ammeter data from the 4 main branch circuits; I'd also like to display the charge rates of my solar panels and wind turbine (those circuits haven't been ran to the control panel yet though, and I don't know if I want to)... I'm also going to attempt to give the panel a Star Trek like feel by hilighting a wire-frame-Airstream model with the data displayed around it; the panel is a piece of Plexiglas with a clear adhesive printable vinyl sheet blacked out in the areas that I don't want light to shine through...

Besides polishing this thing, the control panel is the last real project to tackle, but I'm still in the wake of enjoying the fruits of my 10 grueling month, +60 hours a week restoration. I've had big plans for that control panel from the start... because I do happen to have an electrical engineering degree

PS I will be utilizing your R2R comparator ratios and relative tank level-resistance data as a baseline though, and THANKS for that!

[stephenh2]

Thanks for the input.

Zep, I did read the whole thread a few days ago. Its still quite a bit over my head... so I think I'll keep my 50 bucks. I don't really have time right now to take on an upgrade like yours. I'm going to be hitting the road with my rig next Thursday.

What do I need to save off of the old Univolt's fuse panel, the whole fuse panel or just the shunt plate? How do I get the plate off, is it riveted onto the fuse panel? (I see the four rivets that fasten the fuse panel to the Univolt) Then, when I get it off, can I connect it to my fuse box with a wire to each end of it and then connected across one of the fused circuits, then just plug my old wires back onto it?

Any other parts worth salvaging on the Univolt?

thanks,
Stephen

[Zeppelinium]

Originally Posted by stephenh2

...What do I need to save off of the old Univolt's fuse panel, the whole fuse panel or just the shunt plate? How do I get the plate off, is it riveted onto the fuse panel? ...

Nothing worth salvaging except the shunt. You can make a new shunt out of 11" of #8 stranded copper wire and two medium electrical cleats, it's not a disaster if you don't save it. If you want a high amp 12V power supply for your shop, sometimes and old Univolt can be used for testing pumps and jacks, etc., but that's the only use I can think of (unless you're building a foam airplane and you need a hotwire cutter).

I recommend against using the Univolt fuse block. Get a new 12V fuse block that uses the mdoern flat automotive fuses.

Zep

[stephenh2]

Zep,

My shop is on my back right at the moment. Don't think I want to carry a Univolt around with me. I'll take a shot at removing the shunt and carry it on down the road for awhile. The Blue Monster will have to stay in Reno, in a dumpster or otherwise. If I can't figure out how to set it up, I can do without a meter for awhile.

Oh, I did replace the fuse block with a new one. I'm very happy with it and highly recommend the upgrade.

Stephen

[Overlander]

In your third photo...the front of the old univolt, there are three wires. A red and black that both have a 90 degree push on type connector that are attached to a flat steel plate "AMMETER BLACK" and "AMMETER RED". And the third is a single gray wire on the bottom right corner with a spade style connector. What are these three wires for and what do you do with them on a univolt replacement. I don't see them on your after photos? Any guidance on this would be great, I'm in the middle of a replacement right now.

[stephenh2]

The Push on red and black wires are for the meter in your control center. I just left mine loose since there is no shunt for an ammeter on the new converter. I removed my fuse panel and saved it with the old shunt intact in case I decide I want to try and reuse it.

I THINK the gray wire is for the "Shore Power connected" indicator light in your control panel. I also left this loose. I just plug something in to and A/C outlet in the trailer if I want to know if I have 110v service connected.

I just got my system to where it is usable and put off the 'extras' until later. I may ore may not decide to connect and use those circuits later on. Best of luck to you.

Stephen

[Silverflames]

Hello all first post.. I have a 27 foot 1969 Ambassador. I just installed the Intelli-Power PD9270 (70 amp model). It went smoth and its running great. Suprised and happy it went so well.

Mine is located under the bathroom sink in the access hatch. I reused the old fuse pannel, and just tied direcly into it. There is not really any room next to the power coverter for a battery, is there any rule on how close the battery has to be to tie it in?

Thanks,

Keith

[stephenh2]

Keith,

Welcome to the forums. It really is satisfying to have an upgrade go so well. Be sure and post some photos. My old fuse panel had some problems, so I just started fresh.

I would prefer to keep the battery as close as possible to the converter. Shorter battery leads are more efficient. I would like to see battery leads less than 8' long. If you go farther away, you should go to a larger gauge lead. I know some folks have gone much farther than that. Do some searching on the forums and you might find a more detailed answer. Where was the original battery box on your Ambassador?

Stephen

[Aage]

Howdy and welcome to airforums.com, Keith!

It's nice to change out the old power supply especially as most of them hum like a good thing.

However, I would recommend you consider changing out the old fuse panel as well. If yours is like mine at all, the fuse clips are corroded beyond safe use, and need to be updated.

For reasonable dollars, you can get a good one like this.

As a bonus, it uses the newer automotive-type fuses that can be bought at almost any gas station.

[Silverflames]

Thanks all!

I will take a look at the fuse panel closely. I will probley end up updating it. I will check the connections and see how bad they look. I don't want any fried wires! I thought about putting the battires in the Closet, but it will probley be close to 8 feet away... mabey I should move the inverter there as well? The only down side, is my wife would have to find a new place for her shoes!

[stephenh2]

Wherever you put the batteries needs to be sealed off from the inside of the trailer and vented to prevent the buildup of explosive gases. Remember that you will have to extend the trailer wiring for all of the circuits if you move the location of your converter. I moved mine only a foot or so from the original location and did not have to splice any wires. I did replace the battery cables to gain about a foot of length.

My space is limited to one battery at this time. The battery box is located under the stove, with an outside access hatch. The door to the hatch is not in the best of shape. There is room for only one battery. I hesitate to do too much modification since I plan on tearing out the kitchen cabinets and redesigning the layout.

Stephen

[Silverflames]

Just a follow up post. Power inveter still working well, have not installed a battery yet, all the places we go have power hook up, and we are no were close to boondocking it yet... Next project is the axles... Wish me luck..