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Author Topic: Newbie electrical questions  (Read 561 times)

WMH Cheryl

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Newbie electrical questions
« on: July 16, 2017, 02:43:15 AM »
I recently purchased my first RV 5th wheel, a used 1997 AutoMate.  The problem I have discovered with AutoMates is that each one was custom made so no two are exactly the same.  I received a generic binder that the Automate club had put together.  Not super useful since most things don't match my trailer.
Bottom line, I am trying to figure out the electrical system and finally found the AC breaker panel and what I assume is a DC fuse panel.
Pic #1 is AC breakers and a few are obvious to me.  Far left Green labeled Main is the master shutoff for AC.  Continuing from there is WH, GFI, GP, AO, MW.   GFI is obvious as any GFI outlets, MW probably for microwave, AO maybe for Air Conditioner?   Would WH be for Whole House?  How is that different than the Main?  No clue on GP. ??
Pic#2-4 are from inside the underneath storage area on the other side of the battery compartment, 50 amp converter on the left of fuse box.  They did something strange in my opinion (but I have no RV experience).  There are two thick sets of red and black wires that travel to the battery box and two 12v batts each have a separate set of wires.  The batts are not connected together there but above the fuse box there appears to be a shunt or something where the two sets of wires join?    Anyone know what that is? 
The reason I am asking is because I suspect that something is funky with the converter or that mess of wires because when I purchased and they had it plugged into Shore power the batts got really hot and after purchase when I removed them to test they are pretty fried, only reading about 3.2 volts each out of 12 so I am guessing that they are fried. 
I will be boondocking and adding a solar system that will be separate from this and just connect into the shore power side and the converter will then in theory just charge new deep cycle batts for the DC side.  I have different solar batts (two 6v 210ah) that will be used for the inverter/AC side.
Any info would be appreciated.
« Last Edit: July 16, 2017, 02:46:25 AM by WMH Cheryl »

Kevin Means

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Re: Newbie electrical questions
« Reply #1 on: July 16, 2017, 03:41:49 AM »
Hi Cheryl, welcome to the RVForum. Congratulations on your new-to-you RV! Documentation for older RVs is usually pretty thin, but for a 1995 RV, you actually got pretty lucky. Your electrical labels seem to still be there, and they're stll readable. Those are often gone within a couple of years.

Like you said, that green breaker labeled MAIN likely cuts off all A/C power to the RV. The next one labeled WH is probably the electric Water Heater element, so you don't have to use propane to heat your water when hooked up to shore-power. GFI is what you said, but GP is a mystery. Maybe General Purpose A/C outlets?? AO must be Air Conditioner (if you've got one) but I have no idea why it's labeled AO. To test it, plug into shore-power, turn that breaker off, then see if your AC will turn on. Then reset the breaker and try it again. And MW I'm sure is MicroWave.

It does sound like your batteries are shot, but I'd make sure the converter (charger) is working before relying on newly installed batteries. Hook the new batteries up, plug into shore-power, then measure the voltage at the battery's terminals. It should be higher than 12.7 volts.

I'd have to inspect the wiring closer before I could determine if there were any wiring snafus, but others here might hazard a guess. And it's just a suggestion, but unless you have a real need for having two separate house battery-banks, it's usually much more practical, and far simpler to have one larger battery-bank - even with solar. Solar controllers are very capable of working harmoniously with other chargers.

2011 Winnebago Tour 42QD
Towing a Jeep Rubicon Unlimited LJ
RVI Brake 2, Minder TM-66 TPMS, 960 watts of solar
(Can't wait to spend more time RVing)
Lakeside, California

WMH Cheryl

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Re: Newbie electrical questions
« Reply #2 on: July 16, 2017, 04:22:09 AM »
Thanks Kevin.  Ahhh. Water Heater makes sense.  I just realized that the refrigerator isn't listed I wonder if is under the GFI breaker?  I will have to do testing, wasn't sure if those breaker markings were standard or not. 

The reason I am considering a separate solar system is because I am used to small off grid  systems that I have around the ranch.  The panels won't be attached to the trailer, etc.  Since I don't understand RV electronics, just seems easier to wire an RV plug into a large inverter and plug the shore power plug into that.  Mainly just to run the refrigerator and freezer on solar and a couple of minutes of microwave occasionally.  Cutting into or changing the current DC wiring makes me nervous. 

The solar system would not travel with the trailer, just for use here off grid so I don't use up propane running the generator or the refrigerator. 

If the shot batteries were so hot when plugged into Shore power, is it possible that the converter was over charging them?


WMH Cheryl

  • Posts: 4
Re: Newbie electrical questions
« Reply #3 on: July 16, 2017, 04:29:43 AM »
Anyone know what this is called?  I find it strange that the two batteries on the other side of the wall are not joined together in the battery box but have two sets of separate wires that join here.  Located above DC fuse box.

Rene T

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Re: Newbie electrical questions
« Reply #4 on: July 16, 2017, 04:35:23 AM »
  If the shot batteries were so hot when plugged into Shore power, is it possible that the converter was over charging them?

Are the batteries wet cell where you can add water or are they maintenance free? Usually on a wet cell battery, due to lack of checking for water, the cells dry out and short out causing them to overheat and the battery case usually swells out. Do you have any idea how old they are?
Rene, Lucille & co-pilot Buddy
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WMH Cheryl

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Re: Newbie electrical questions
« Reply #5 on: July 16, 2017, 04:42:25 AM »
The batts have a 2014 sticker.  When I pulled them out there were some cells that needed distilled water added.  Unfortunately when I hooked up a solar panel and charge controller to one the super low voltage is causing the charge controller to error out.  I will have to take them into town to be hooked up to a smarter charger on AC to see if they can be brought back.  Not real optimistic about that with the 3 v reading.
Whoops, yes they are wet cells.  Flooded lead acid.


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Re: Newbie electrical questions
« Reply #6 on: July 16, 2017, 09:42:47 AM »
For a good lesson on RV electrical, Google "Jack Mayer".  Look at his electrical section.
I know you believe you understand what you think I said,
But I am not sure you realize what you heard is not what I meant

2016 Leprechaun 319DS

Gary RV_Wizard

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Re: Newbie electrical questions
« Reply #7 on: July 16, 2017, 11:18:56 AM »
GP is typically 'General Purpose' and simply means the circuit handles multiple things. Might, for example, have refrigerator, the converter/charger, and maybe a couple outlets. RV builders tend to design for their own convenience in the assembly process and building the wiring harness to work on multiple models.

Gary Brinck
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Home: Ocala National Forest, FL