Electrical system Replacement

[motorcarmike]

Hey all.

Ive been searching and searching and there is so much information out there, but id like to reach out to my fellow fiberglass RVers.

I am replacing my entire interior electrical system in my boler and want to keep it really simple. I only want one plug in for 110V which would only be used to run shore power. The rest will be 12V lighting.

What do i need to bring my shore power to 12V? transfer switch?

30Amp converter charger?
circuit breaker to protect converter?

any help or advice would be great!
Thanks
Mike

[Defenestrator]

If you don't use an inverter (that is, 120V only available when on shore power), you don't need a transfer switch. Just a converter/charger, and optionally a power protector.
You'll need some breakers, fuses, and cutoff switches, but those are sometimes integrated with the converter/charger.
One main breaker leading in. Possibly separate breakers for the outlet and the charger. A cutoff switch for the battery. A main fuse on the battery plus individual fuses for various 12V systems.

[Gerry]

As Elliot said, just a converter to convert the 120V down to 12V will do. Some new converters will come with all components Elliot mentioned above and all that is needed it to run the wires to the new converter.
When I replaced my original converter in my 78 Boler I had to cut the placement hole just a wee bit larger and the new convert went in the same location. I then ran some 12/3 electrical wire (like you buy for house wire) to where I wanted the 120 wall plug of the terminals marked for such on back of the new converter, and all the 12 volt lines to different sections of Boler lights, fan, fridge, Furnace.
Years ago I had rewired entire inside of Boler and color coded all these separate appliances. Makes it a lot easier to locate if any problem comes up on any on item.

[motorcarmike]

I did come across this drawing when searching on here. I notice there are no fuses or breakers.

I do see the converter/charger i was looking at has a 30A fuse.

In the drawing, the terminal block could be changed to a fuse block going to the various 12V circuits, correct?

The cut off switch is just to shut the entire 12v system off right?

Thanks for the help. Ive done plenty of vehicle electrical but the charger/converter is throwing me off on how to properly wire it in.

Mike

[steve dunham]

I would wire the trailer to current RV industry and NEC standards .
The additional cost and installation time is minor and when you go to sell the,trailer you will recover your money IMHO
Doing a job twice never pay.

** Advice from an old retired electrician **

[motorcarmike]

Which would be?
I just didnt want to buy a big fancy transfer switch. Currently there is no electrical left in my boler. Being a flat top boler, it didnt have much to begin with.

[Defenestrator]

Correct on all accounts.
Replacing the terminal block with a fuse block should work well.
The cutoff switch cuts the battery off from everything, for storage or safety when working on it.

[steve dunham]

I also don't see any propane, carbon monoxide or smoke detection ,or proper overcurrent protection, or proper bonding or GFCI protection , etc . The wiring in most FG trailers is minimal at best.
so cutting it any farther just amplifies the short comings.
I would suggest you find a Scamp wiring diagram and use it as a starting point.

[Joe Romas]

Mike.
All you need is a simple converter. It will have space for 120 volt breakers, you'll need 2, one for the converter and one for your AC outlet, charge your battery and have a combined fuse panel and terminal board for 12 volt DC uses. All in one simple package.

NO transfer switch needed! 12 volt stuff runs off the battery that is kept charged by converter when on shore power.

Here's one that might fit your needs.
https://www.amazon.com/WFCO-WF-8735-...8&s=automotive

Joe

[motorcarmike]

Originally Posted by Joe Romas

Mike.
All you need is a simple converter. It will have space for 120 volt breakers, you'll need 2, one for the converter and one for your AC outlet, charge your battery and have a combined fuse panel and terminal board for 12 volt DC uses. All in one simple package.

NO transfer switch needed! 12 volt stuff runs off the battery that is kept charged by converter when on shore power.

Here's one that might fit your needs.
https://www.amazon.com/WFCO-WF-8735-...8&s=automotive

Joe

thanks,
the link didnt work, but im guessing it was this..
https://www.amazon.ca/WFCO-WF8735P-B.../dp/B004LF13GA

what is the difference between that and this?

https://www.amazon.ca/WFCO-WF9855-Mo...rter%2Fcharger

just a fascia panel?

[motorcarmike]

Originally Posted by steve dunham

I also don't see any propane, carbon monoxide or smoke detection ,or proper overcurrent protection, or proper bonding or GFCI protection , etc . The wiring in most FG trailers is minimal at best.
so cutting it any farther just amplifies the short comings.
I would suggest you find a Scamp wiring diagram and use it as a starting point.

Thanks for the reply, I totally agree about the detector stuff. those will be battery operated so no need to wire them in.

I dont have a sink, water pump, fridge, stove top or anything like that. When i say basic, i mean basic lol. I did find the scamp electrical drawing...and there is a lot more going on than i need.

[motorcarmike]

i tweaked that earlier drawing a bit to see what you all think. is this the proper way to hook up the charger converter?

[Joe Romas]

Mike

A converter would contain the fuse block, converter and circuit breaker shown seperatly on the drawing into one compact box. Item #3 would go directly into item #2 and the two breakers would be one used for the outlet(s) and the second to the converter.

More like the Scamp drawing.


Joe

[David Tilston]

Originally Posted by motorcarmike

i tweaked that earlier drawing a bit to see what you all think. is this the proper way to hook up the charger converter?

What I noticed missing is a frame ground for the converter.

[Franswa]

the OP is in the automotive biz....I'm sure he knows there are some very good, super-smart chargers out there now...the double insulated ones don't need/have a fan (fan noise can get annoying)...and are designed to serve as a power supply with or without a battery in the circuit.....

the diagram shows only 4-5 lights !!! a three position fuse block would be plenty...

I have WAY more 12V appliances than that (furnace, pump, small inverter) and have been using a system like the one below for 3 years (no converter...no problem)....my charger is 7.2A

(and BTW, unlike cars, trailer manufacturers do NOT use the frame as neg. 12V ground....for the trailer lights or the interior lights/appliances....they use neg. ground return wires for everything...neg. wire for trailer lights goes to the trailer plug and that gets grounded to the tow vehicle frame)

anyway, this is just another option....ain't better, ain't worse....just different....some would say simpler

[David Tilston]

Originally Posted by Franswa

(and BTW, unlike cars, trailer manufacturers do NOT use the frame as neg. 12V ground....for the trailer lights or the interior lights/appliances....they use neg. ground return wires for everything...neg. wire for trailer lights goes to the trailer plug and that gets grounded to the tow vehicle frame)

The ground wire I was referring to was for the 120VAC. The green wire, on my converter, is run through the fiberglass and terminated on the frame.

[motorcarmike]

Originally Posted by David Tilston

The ground wire I was referring to was for the 120VAC. The green wire, on my converter, is run through the fiberglass and terminated on the frame.

could the ground for the converter be ran to the 110v outlet box? that should be be grounded when plugged into shore power right?

[motorcarmike]

Originally Posted by Franswa

the OP is in the automotive biz....I'm sure he knows there are some very good, super-smart chargers out there now...the double insulated ones don't need/have a fan (fan noise can get annoying)...and are designed to serve as a power supply with or without a battery in the circuit.....

the diagram shows only 4-5 lights !!! a three position fuse block would be plenty...

I have WAY more 12V appliances than that (furnace, pump, small inverter) and have been using a system like the one below for 3 years (no converter...no problem)....my charger is 7.2A

(and BTW, unlike cars, trailer manufacturers do NOT use the frame as neg. 12V ground....for the trailer lights or the interior lights/appliances....they use neg. ground return wires for everything...neg. wire for trailer lights goes to the trailer plug and that gets grounded to the tow vehicle frame)

anyway, this is just another option....ain't better, ain't worse....just different....some would say simpler

Wow! im liking this! this is super simple. ive looked at those Noco chargers at canadian tire before! never though about using it for this...

so heres a dumb question...what is a charger/ converter doing that is different than a regular 12v charger? just allowing you to use a 110v outlet off 12v like an inverter?

[David Tilston]

The case of your converter, the frame of the trailer, everything conductive should be tied back to the ground at the outlet.

The ground wire serves two functions. One is that everything you might touch will be at ground potential. I still remember grabbing a pop out of the fridge, in a friends basement. I am assuming that the ground wire was not connected, because when I grabbed the handle, (while in bare feet on the concrete floor) I was electrocuted. It was a good thing that the resulting spasm caused me to fling the fridge door open and pulled the handle out of my hand.

The other function is to ensure that everything around the conductors is at ground potential. That way, if a hot wire comes loose, then the first thing it touches will cause the breaker or fuse to pop.

[Franswa]

first, when I said no grounding to frame (if you reread the post) I was only talking about the 12V side....the OP had 12V negative grounded to frame in his first diagram.

and yes the converter is grounded to frame AND is grounded through the shore power plug ground wire (to the house or RV park grounding) as well....

in the pics below both are visible (my old power center)....the light green wire from the shore power cord....and the larger dark green wire that I assumed was grounded to the frame of the trailer frame somewhere

all this does bring up an interesting point though.....unless the trailer has the jack down or leveling jacks cranked down there is no grounding through the frame (tires insulate/break the circuit to ground)....in that case it's the house/RV park ground that would provide grounding.....just thinking out loud here....( I have in the past plugged into shore power at a RV park and stayed hooked up to the TV with no jacks down)

in most cases there will not be AC power in the trailer unless it's plugged in and grounding can be provided by the shore plug's ground.....only exception would be when an inverter is used (unplugged from shore power)....then the trailer would NEED a ground...but would not have it unless the steel frame made contact with the dirt through the jack(s).....I wonder how they deal with this in Motorhomes that are just sitting there on tires (insulated from ground)....anybody have an answer to that ???

and for the OP......trailers generally come with POWER CENTERS....these include an AC breaker box, a DC fuse box AND a converter/charger compartment (usually found at the bottom of the power center)....in that same compartment there is a relay (small black box in first pic)...when plugged in the relay is tripped and 12V power is supplied to most DC circuits from the converter (not all circuits but that's a WHOLE other thread)...and the battery is charged at the same time time by that converter....when the trailer is unplugged the relay switches back and all 12V power comes from the batteries....hope this helps/clarifies...