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Small Cabin Forum / Cabin Construction / What gauge wire... (and BBQ pipe/tubing)
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DaJTCHA
Member
# Posted: 17 May 2012 13:29
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I'm in the process of reworking the roof on a CL freebie (a 1965 Banner camper) from a flat to domed roof and figured now was the best time to run wires for 12v lighting. Since I'm building a frame that will be secured through the top that is already there, I can drill the holes exactly where I want the light and use the cavity that I create above to make the wire runs. The question is this: If I plan on using (this is if I don't go superbrightleds) 5 of the 15watt fluorescent light fixtures (at the most) what gauge wire do you think I should use? I'm going to take a guess and say 16, but I'm sure there are others than know better than my guesstimate.

Another question...I've removed everything that runs on propane except for the stove. I'd like to put an "outlet box" with a snap cover on the outside of the camper wall directly behind where the stove is located and run a brand new (very short length here) of propane hose from the fitting on the stove to the outlet box on the outside. The idea is I can store the propane tank when not in use and place in on the ground when we're up at camp and want to make coffee and breakfast in the morning. Can I purchase (at a store) a 5' length of flexible gas tubing that has the propane tank fitting on one end and the appropriate fitting to match the stove fitting on the other? How would you go about this endeavor?

Thanks ahead of time, you guys are great and this forum is an invaluable educational asset!

MtnDon
Member
# Posted: 17 May 2012 14:32
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I didn't see how many feet of wire run there would be, one way direction total, battery to furthest light.

Propane. Get a rgulator you can mount to the exterior wall. Connect the regulator to the stove using copper tubing (sold in a roll or by the foot at many places). There should be a flare fitting at the stove, probably for 3/8 tubing, but check. Fit the flexible hose to the inlet side of the regulator. Use the Acme nut to connect to the propane tank when on site. Do not run flexible hose through a wall to the inside.

DaJTCHA
Member
# Posted: 17 May 2012 17:42
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How'd I know that MtnDon would answer my ???'s

From where the battery box will be located to the furthest light, I'd say about 30-35ft? All the lights will be the 8w fluorescent fixtures.

I did a search for wall mounted propane regulator...they're not cheap?! $98 is what I'm finding, OUCH!

DaJTCHA
Member
# Posted: 17 May 2012 18:16
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I don't know if this is a stupid question or not, but why can't I run a short length of black gas pipe with a fitting at one end to accept the yellow coated flexible gas pipe to join to the stove inlet? At the other end the black pipe would exit the wall of the camper had an immediate elbow with a short nipple of pipe on it that feeds to the regulator and then has a short rubber hose that would thread up to the propane tank?

toyota_mdt_tech
Member
# Posted: 17 May 2012 18:19 - Edited by: toyota_mdt_tech
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You could get a propane regulator from Home Depot in the BBQ section, but its not rated for anything but that but works great. . Use 3/8" copper line, you MUST use a double flare for the ends, (put the fitting on before you flare it) or a ferrule type fitting for those without a double flare tool. The ferrule slides over the tube, tighten down the ferrule nut and it crimps onto the copper pipe/tube

LED lamps will use very little current. But could someone try to hook it back to std bulbs? If so, use 14AWG minimum. Othwerwise, certainly be able to go smaller.

MtnDon
Member
# Posted: 17 May 2012 18:37
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Quoting: toyota_mdt_tech
The ferrule slides over the tube, tighten down the ferrule nut and it crimps onto the copper pipe/tube


Flare fitting, including reverse flares are the only type of fitting approved for propane gas, other than threaded pipe fittings as used in rigid black iron pipe. ... Since propane leaks can be dangerous I would not recommend deviating from that.... I did once need to make an emergency splice in some soft copper tubing and used compression fittings as that was all I had on hand in the boonies. It leaked ever so slightly.

DaJTCHA
Member
# Posted: 17 May 2012 19:11
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So, if I understand this correctly I could use rigid black pipe on the outside with regulator attached to the end...pipe goes through the wall and into the camper and then on the end of the pipe, a flexible gas pipe from the threads to whatever the stove fittings are in size?

MtnDon
Member
# Posted: 17 May 2012 23:48 - Edited by: MtnDon
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Black iron pipe has the advantage of being resistant to damage. Soft copper could be used from the regulator to the inside if protected against abrasion where it passes through the wall. From there to the stove could be soft copper with flare fittings or if the stove is movable one of those corrugated flexible yellow gas lines.

toyota_mdt_tech
Member
# Posted: 18 May 2012 00:45
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Don, I did use double flared at both ends (as a Toyota dealer tech, I have this tool on hand) of my copper pipe to my cabin. The copper runs right to the RV stove. I did however use a BBQ regulator from Home Depot which comes with the rubber whip hose too, cost was about $20. My copper pipe is secured all along the way, with band clamps, but the band clamp has the rubber insulator. Dont secure the copper with any dissimilar metal, you will get corrosion.

DaJTCHA
Member
# Posted: 18 May 2012 10:25
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Awesome! MtnDon...what do you think about the gauge wire for my overhead fluorescent lighting? I'll never have them all on at the same time, but I plan on using the 15watt X 5 units.

Thank you as always!

MtnDon
Member
# Posted: 18 May 2012 13:02
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Distance of wire run?
The goal is to keep voltage drop below 3%.
So 12 vdc 3.75 amps, let's call it 4 amps for three lights on at one time.

#14 wire is good for 15 feet
#12 = 23 ft
#10 = 37 ft
#8 - 58 ft

You can see why I don't like 12 volt systems. Most things like lights can run ok on reduced voltage. But FL lights are going to be more critical than incandescent.

DaJTCHA
Member
# Posted: 18 May 2012 13:04
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Ouch! Maybe I should consider all LED lighting instead. The cost of the wire along is a fortune now that copper is a precious metal,

razmichael
Member
# Posted: 19 May 2012 08:51
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Something that may be applicable here is that most (at least in the last 15 years) propane systems in popup trailers and (I think ) RVs are low pressure systems for safety and to meet code. Thus, the stoves are also low pressure stoves (although some will actually work better on high pressure but this is not recommended). The advantages of a low pressure system is that you can use the quick connect connectors on the propane. My popup has a stove that can be used both inside and moved outside. Propane distribution below the trailer is copper wrapped in a protective cover but the connections inside and through the wall to the outside are flexible black hose with quick connect fittings. Disadvantage - a low pressure stove does not work nearly as well as a good old coleman camping stove. I admit that I do not use our popup stove and do not even take it with us.

On the wiring side, you should be considering the complete distribution system - battery cut-off, main fuse (could be the same thing) and then small fuse for your lights. Consider that you will likely want to add something in the future so don't just run power from the battery to the lights. A very cheap but flexible DC distribution/fuse setup can be done easily and cheaply. Here is an example of a small one I use Photo DC Distribution .

DaJTCHA
Member
# Posted: 19 May 2012 10:24 - Edited by: DaJTCHA
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Razmichael-

Thanks for your input. I was discussing the electrical system with my neighbor and he just happens to have 10 gauge wound and jacketed wire in spools of 200 ft! He said I'm welcomed to use what I need. WOO HOO! Talk about a savings find there!

Here's the stove that I've yet to pull out to inspect how the fittings are sized and oriented. The camper has (2) 30# propane tanks that I'll be removing eventually after I use the rest of the gas from them.

I'm hoping and thinking that this is low pressure LP because of the tanks and I'm fairly sure that they've got flexible copper running everywhere (in and out) of the camper. I'm going to be removing all of it for scrap and then going to fabricate the short run directly out of the wall as I had mentioned earlier.

Here's a photo of the free camper and the stove in question:
BannerCamper.jpg
BannerCamper.jpg
BannerCamper_Stove.j.jpg
BannerCamper_Stove.j.jpg


DaJTCHA
Member
# Posted: 19 May 2012 10:43
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You can see, given the plan of attack on the new LP run, that the run will be extremely short out of the back of the stove and through the wall. The only thing that will have gas fed to it will be the stove when I'm done gutting the rest of the appliances. I sold the fridge, I'm removing the "hot water" tank and heating element and I'm also removing an old "steven's" pressurized water tank and system. The need to replumb was created by the comment from the couple who gifted it to us that they think the stove has a small leak and to have it inspected. It is an awesome appliance though and it reminds me of my grandmother's kitchen stove only miniaturized.

In reference to the comment regarding lighting and future expansion: Realistically, the only thing we'll be using the power for is lighting. Eventually, I'll transition from the act of toting a recharged battery back and forth from home to a small portable solar array that charges on site. We'll see where it we go with this project.

I want to say thank you to the admin for allowing this slightly off topic thread to remain as I believe that it has some useful information that can be used in similar situations within a cabin!

razmichael
Member
# Posted: 19 May 2012 14:37
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Quoting: DaJTCHA
In reference to the comment regarding lighting and future expansion: Realistically, the only thing we'll be using the power for is lighting.

I'm sure you are not the first person to say this and then.. next will be a small pump, then something to charge an mp3 player, then a couple more reading lights and then..... Regardless you should still consider that you do need to properly fuse things - 12V DC from a battery can still cause a short and a fire - even a small battery has a lot of power. Got thing about a camper is that you can use the frame as the ground in most cases. The small distribution setup I linked to would cost about $10 (less fuses) and allow for 3 circuits (given the right wire and fuses). Just something to consider.

DaJTCHA
Member
# Posted: 19 May 2012 15:52
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Razmichael-

I apologize, yes...I agree totally with your suggestion! A fused distribution system will be part of the initial wiring plan. TY!

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