electrical

[kent osborn]

Thanks,

I looked around briefly behind the goucho, but I didn't see anything; next time we go back I'll look much closer.

When we were working on the electrical system today
we discovered that the Uni-volt system was kaputz.
The previous owner had moved the system under the sink which
has a leak.

So Obie One came up with the idea of installing a 3000 watt
dc to ac inverter that has a built in battery charger. We were thinking of hotting up all the plugs, all the time that way. If we move the system back to over the axel and install two sealed batteries that are run parallel I think we will be okay.The other thing is that our tow vehicle came originally with two batteries also (camper special). As long as we are careful with our electrical use. Have you ever heard of any one doing this in an A/S???

Thanks

[59toaster]

Originally posted by kent osborn
Thanks,

I looked around briefly behind the goucho, but I didn't see anything; next time we go back I'll look much closer.

When we were working on the electrical system today
we discovered that the Uni-volt system was kaputz.
The previous owner had moved the system under the sink which
has a leak.

So Obie One came up with the idea of installing a 3000 watt
dc to ac inverter that has a built in battery charger. We were thinking of hotting up all the plugs, all the time that way. If we move the system back to over the axel and install two sealed batteries that are run parallel I think we will be okay.The other thing is that our tow vehicle came originally with two batteries also (camper special). As long as we are careful with our electrical use. Have you ever heard of any one doing this in an A/S???

Thanks

Inverters are brutal on batteires. Takes a LOT of 12v power to put out 3,000 watts. Be very selective in using it. Service van I built I had a 2500 watt and with about a 5 amp 120 draw it would low volt the battery in about 1.5 hours

[kent osborn]

Thank you for your advice.

We are still looking at the idea, but any advice I can get is good
advice.

[Tinsel Loaf]

I pulled the two batteries out and put one 12 volt 310 amp sealed concord battery it their place, under the couch between the now empty battery boxes. Put a 3000 watt pro sine inverter in. The wiring was a pain but everything works very well. The inverter draws 60 watts when it is running but you will find you will not be using it much while boondocking. I love the 120 amp charger and the voltage regulation you get while at low voltage camp sites. All in all it is worth it for the convenience.

[kent osborn]

Hi,

I went to start a new job today and the tenants still had not
moved out!! Great so I ran to the A/S to do some more work.
I was looking for the acess panel so we could replace the
embilical when we get it from Inland Rv. First I pulled out all
the bins under the goucho and saw nothing but the 12"x12" floor?? So I thought maybe it was under the water tank and took that out to; nada. Now it was time to get serious so I took out
the goucho and stripped off all the flooring up to the door; nada!!
What? Was the access panel guy on vacation that day? What helped me was the advice I recieved from everyone and the lady from Inland told me that the cord was 7' long. So I measured back
from the male end on the hitch and cut the floor open and there it was!!!

(next time I'll set the depth on my saw less, it is easier on the
blade when you pass over the frame that way)

Thanks everybody!!!

[markdoane]

3000w inverter? Those are pretty expensive, aren't they? Please post if you find a good price. Are you going to get pure sine wave or modified?
Here's an idea-buy a big, cheap inverter for things like the coffee pot and lights, and buy a small, really good full sine wave for the TV and computer monitor.

[kent osborn]

Your' re right,

They are expensive!!! The one we got is about 1500.00 and it is not a sine wave. We are not, as far as I can tell now, going to be running a computer or anything that fancy. What our intention is to hot up all the plugs all the time; but what we are trying to
work out is weither or not we can incorporate the batteries
from our truck into the system or if we should keep the systems totally seperate.
What we are afraid of, is since this thing is an inverter/battery
charger is that it might cause problems with the elctrical system
in the tow vehicle. Our electrician (Obie one) is working out
the details. Obie said the same thing that you did about getting
two of them, because what he was concerned about was that
we may not be able to run cell phone battery chargers or
power tool battery chargers. But we do have one of the Honda
2000 eu generators.

Any other ideas???

[thenewkid64]

The only way to run the inverter off all four batteries is to have a huge (gauge 0) wire running from the truck batteries to the inverter. Also ALL four batteries need to be the same size and type for the system to not kill single batteries. Running the inverter off the 2 internal batteries will work fine, but you will need to watch the usage. Most inverters only output the amperage that is required by the devices that are plugged in. This means you will be able to run a TV lots longer than a coffee maker.

[Hit'nMiss]

Gee I wonder how Kent Osborn's inverter set up worked out. But I guess we'll never know as he hasn't checked in since January 2004. Another (countless) disappeared member and another (countless) unfinished story.
I read somewhere that the Osborn's traded their Safari for a 2004 Bambi. Assuming the converter was in the Safari I wonder if they left it in the trade-in? Doubt they got much extra credit for it if so.

Flicka

[sprusegoose]

I am presently wiring my 69 caravel to use a 2800 watt pure sine wave inverter/charger. Running shore power to inverter/charger. When not on shore power the inverter will draw from the battery pack ( 6- six volt).
Also have two 120 watt solar panels charging my batteries. Only will do it once, hope it it done correct. Will power entire camper with shore or inverted power.

[Janets Husband]

Ok these projects sound really good however, Lets look at some facts about inverter as a load.

Lets pick a 3000 watt inverter, and lets make an assumtion that it is say 90% efficiant, that would mean at full rated draw it would pull 3300 watts.
3300 watts devided by 12 volts is 275 amps.

Looking at an ampacity table, we find we will need to use 2/0 copper at the 90deg. C rateing.
The voltage drop should not be a problem at the lengths of wire required.
(If you keep the two way wire length under 20')

2/0 awg THHN cable for those of you who have not used it can be a bear to use. If you need to terminate it most people will not have the crimpers needed to do the job correctly.
If you use bolt on connectors you will need to check them from time to time.


I have for many years installed battery banks for large communications systems, and I have found that useing "Welding Cable" for the main supply is the way to go. More expensive but much more flexable and easier to route. Use a good quality 600V rated cable and secure it with plastic cable clamps every 3' or at any turn. Note: when spec'ing this cable, standard AWG lugs won't work, you must size welding cable connectors.

A bit of trivia: When traveling Janet and I use a small electric heater to heat our trailer it is rated at 1800 watts. It has all the poop needed for all but the coldest nights, and I haven't seen one of those yet.

In doing this job you are working with enough power to heat a large trailer, and you don't want your primary wirering to become a heater.
So don't skimp on this installation, or you might end up with a pile of scrap aluminum for your troubles.

[sprusegoose]

I am placing the battery bank on the front with the inverter in its own box in front of the bat box. Shore power going directly into the inverter. Bat charger lines should be less than three feet long. Same with the bat power lines coming back to the inverter. The 12 volt breaker box will be inside the caravel- estimate 5 ft cabling. Plan on using 8 gage wire for all 12 volt system. In reading 12 volt info- I find that the voltage drop is calculated on the total wire lenght ( to and from the breaker box). Caused me to increase the wire size.
Dan
69 Caravel

[Janets Husband]

Originally Posted by daniel

I am placing the battery bank on the front with the inverter in its own box in front of the bat box. Shore power going directly into the inverter. Bat charger lines should be less than three feet long. Same with the bat power lines coming back to the inverter. The 12 volt breaker box will be inside the caravel- estimate 5 ft cabling. Plan on using 8 gage wire for all 12 volt system. In reading 12 volt info- I find that the voltage drop is calculated on the total wire lenght ( to and from the breaker box). Caused me to increase the wire size.
Dan
69 Caravel

The charger will only supply what it is rated at. Maybe 60amps? 8awg wire will work just fine for that.
The feed to the inverter DC/AC should be the heavy cable.
If the inverter can draw 275 amps at full rate (3000W), you will need to size this wire so that it will not melt.
The voltage drop should not be a problem with that short of a run.

[74Argosy24MH]

Originally Posted by Janet's Husband

Ok these projects sound really good however, Lets look at some facts about inverter as a load.

Lets pick a 3000 watt inverter, and lets make an assumtion that it is say 90% efficiant, that would mean at full rated draw it would pull 3300 watts.
3300 watts devided by 12 volts is 275 amps.

I did exactly this, a 3000 watt inverter which runs the whole mh. True the cable needed is heavy (I used 4/0) and it takes some planning to install properly. It should not foul anything and definitely should be fused. When you get to this size inverter a lot are also chargers (make sure you don't get into a loop where the batteries feed the inverter to make ac which feeds the charger and then charges the batteries). Combining functions makes installation easier and does free some space. The chargers and inverters usually are better quality than the smaller ones with a higher charge rate, stepped charging, and better ac waveform.

The alternative of using a smaller inverter, isolating circuits and installing a subpanel is not that easy. I knew no matter what circuits I did not include would be the wrong one(s) to leave off. Finding a location for the subpanel, running and concealing the new 120v wire looked like a lot of work. By using the large inverter I could hook into the existing wiring where it entered the mh, much easier than the subpanel route.