Electrical Wiring Placement and Connections

[Vernation]

Hi There,
The time has come to start putting the wiring back in the Safari.
I have some general circuit questions and a specific how did you solve this issue question.


I plan to put the interior back how it was, so the light fixtures will be in the same place as before, but there are some extra electrical items that weren't part of the original design--two fantastic fans, tank monitors, that kind of stuff.


General questions: Should the fans each have their own separate circuit? Should the tank monitors and water pump be on their own dedicated circuit?


Specific question: The lighting is all over the place--there is no elegant way to connect them in parallel without many connections (crimps / wire nuts) being located behind walls. Since a connection is the most likely place for an electrical failure, I hate to put them somewhere hard to reach in order to repair.


The Safari had/has three junction boxes up in the cabinets, but they are out of the way of everything. It would be quite a detour to use them. As much as possible, I am trying not to put extra holes in the walls. Even if I made new junctions somewhere else, I can't imagine where I would place them to be convenient to all the lighting.


How did you solve these issues? Do you have a favorite connector? Did you end up putting some connections behind walls? Did you just have long individual runs to the junction boxes?


Help me picture this.
Thanks.

[ITSNO60]

Originally Posted by Vernation

Hi There,
The time has come to start putting the wiring back in the Safari.
I have some general circuit questions and a specific how did you solve this issue question.


I plan to put the interior back how it was, so the light fixtures will be in the same place as before, but there are some extra electrical items that weren't part of the original design--two fantastic fans, tank monitors, that kind of stuff.


General questions: Should the fans each have their own separate circuit? Should the tank monitors and water pump be on their own dedicated circuit?


Specific question: The lighting is all over the place--there is no elegant way to connect them in parallel without many connections (crimps / wire nuts) being located behind walls. Since a connection is the most likely place for an electrical failure, I hate to put them somewhere hard to reach in order to repair.


The Safari had/has three junction boxes up in the cabinets, but they are out of the way of everything. It would be quite a detour to use them. As much as possible, I am trying not to put extra holes in the walls. Even if I made new junctions somewhere else, I can't imagine where I would place them to be convenient to all the lighting.


How did you solve these issues? Do you have a favorite connector? Did you end up putting some connections behind walls? Did you just have long individual runs to the junction boxes?


Help me picture this.
Thanks.

Avoid making any splices in inaccessible areas period. You either run power to switches then from switch to first light, then on to 2nd light etc. or run power to light first and a switch loop down to switch (If you do this run a spare negative otherwise there will be no negative at the switch for future use, or for switch illumination, USB charger etc). All splices are at switch locations or light locations and accessible by removing the devices or fixtures. There is no reason to make splices in inaccessible locations and in fact if you were wiring a building it would be prohibited by code, (I don't know what RVIA or AYBA has to say about 12 volt splices though, maybe someone here can enlighten us on that.) Remember to leave enough slack in the wires to be able to pull them out far enough to access the splices.

For things like your fans you can always run a separate line to each one then you have the option of putting them both on one circuit or each on it's own at any point in time without having to run more wire after the walls are covered. More wire yes but running more wire now is 10 times easier than after the walls are covered.

There are always handy places to hide splices and still have them accessible, like behind smoke and CO alarms, inside furnace closet, behind medicine cabinet or mirror, behind plumbing access panels etc etc but in reality planning it so they all end up at the fixtures and switches is easily done, in fact it's the easiest way. Using these alternative locations is usually for later additions or repairs and shouldn't be necessary on a clean slate with full accessibility.

Keep in mind at any lights where you might want a USB charger to run both a switched and an unswitched, or power to the light first and a switch loop down to the switch with a spare negative as mentioned earlier.

edited at 6:43 for additional info

[ITSNO60]

Note, everything in my post above refers to 12 volt DC wiring, not AC line voltage! All line voltage splices must be contained in approved enclosures!

[mrdes8]

Hey, must feel good to move on to another stage of the project. So many things encompassed here, design, electrical engineering, best/safe practices, expressing your own style. A few wide ranging comments/ideas... I usually can't believe how much wire Airstream ran and where they put it. Th '68 had so much wire everywhere, battery and 110v originating in curbside rear and going all over the trailer, including the crazy control center. I like to try to get as much of my electrical "stuff" near the trailer center streetside (including batteries for solar), shorter runs, less wire etc. A single circuit for ceiling fans can certainly work if you know the power draw and size your wire and fuse properly. Yay! for LED lights, a whole center trailer circuit on 15 amp fuse. I try to keep as much wiring as possible NOT in the ceiling and on the ribs as much as possible, no 110 stuff just straggling across the center of a bay messing up the insulation. I'm not against going under the floor if done properly. Marine wire is nice to work with but pricey and needs wire connectors at almost every end, particularly 110 stuff. Whatever connectors you use get a good ($30-50) crimper tool for proper crimps.
Much more to possibly say or think about. Previous advice was all good. Take pics of what you do so you can find that elusive wire. I would say I used 1/3 the wire that Airstream did. (And plumbing too.)
Good luck, Mark D

[Vernation]

@mrdes8


"I try to keep as much wiring as possible NOT in the ceiling"


Why do you avoid the ceiling? I've seen other people try to put it up there exclusively, for easy access, I think...



Completely agree about the crazy amount of plumbing and wiring in the original layout. Makes you go, "Surely there's a more efficient way to do this..."





@ITSNO60


"you can always run a separate line to each one then you have the option of putting them both on one circuit or each on it's own at any point in time without having to run more wire after the walls are covered. More wire yes but running more wire now is 10 times easier than after the walls are covered."


Ain't that the truth! There's a bit of analysis paralysis going on over here, just knowing that whatever I put in there, I'm going to have to live with.

[SSquared]

I recently did a water pump replacement and saw the instructions recommend having a dedicated circuit for the pump. Pumps do draw a fair amount of current when running--I think in the 6-10 amp range--so they don't share well with other significant draws.



We got a SeaFlo brand replacement pump that drew so much current when it ran that it made all the lights in the trailer blink (even on different circuits)! That pump lasted a week before I ripped it out and put in a Shurflo.

[kb0zke]

Yes, a water pump can be a fairly high-current item, but only when it is running. How much do you run the pump? Is there a lower-current item that is unlikely to be running at the same time as the pump? If so, they could be on the same circuit.


Yes, there should be a continuous wire run from one point to another - no junctions or splices between the two points. That said, it might make sense to put a junction in a place where a future item will go. Maybe you are undecided about lights over the bed, for instance. Run the wire with a junction box anyway. Then, if you decide to put in the lights, the wiring is already there. If you decide against them, so what?

[ITSNO60]

Originally Posted by kb0zke

Yes, a water pump can be a fairly high-current item, but only when it is running. How much do you run the pump? Is there a lower-current item that is unlikely to be running at the same time as the pump? If so, they could be on the same circuit.


Yes, there should be a continuous wire run from one point to another - no junctions or splices between the two points. That said, it might make sense to put a junction in a place where a future item will go. Maybe you are undecided about lights over the bed, for instance. Run the wire with a junction box anyway. Then, if you decide to put in the lights, the wiring is already there. If you decide against them, so what?

We do that a lot in homes but no J-box, we just place the extra wire in a loop and do not connect the other end, then label it and photograph it.

[mrdes8]

Yeah, so in my mind the insulation, especially in the ceiling is more important than the wiring which can be done several ways. In my '68 Overlander it seemed like wires were everywhere with no real plan to it, often making large areas between the skins poorly or even un-insulated. I am a fan of separate circuits for all the individual appliances, with appropriate wire size and fusing. Now, when you get to the early 70's, Airstream began to put a 10"-12" panel down the center of the ceiling with access for all the wiring, a somewhat reasonable idea, but again leading to poor insulation in that critical area. I spent 40+ years in the automotive industry and decades as a serial home renovator so along the way I picked up all kinds of ideas on how I liked to do things. Concerning automotives, one of our favorite sayings became, " so you gave them (engineers/designers) a chance to think about it and they came up with this!". Next we can tackle the AC side of it.
Good luck, Mark D

[Vernation]

"Next we can tackle the AC side of it."


The AC side doesn't seem as complicated:
I have 5 outlets, one on each wall plus one (refrig).


I can't imagine how I would route wires to cover all of them in one go, so I was going to take ITSNO60's advice and just send wires to each of them and hopefully combine them at the panel.


AC and Refrig get dedicated lines...


The only question that comes in is whether I want to run extra wires for possible future (or present) upgrades. --wifi boosters, etc that were never part of the original plan.



Unless of course, I'm missing something...

[ITSNO60]

Originally Posted by Vernation

"Next we can tackle the AC side of it."


The AC side doesn't seem as complicated:
I have 5 outlets, one on each wall plus one (refrig).


I can't imagine how I would route wires to cover all of them in one go, so I was going to take ITSNO60's advice and just send wires to each of them and hopefully combine them at the panel.


AC and Refrig get dedicated lines...


The only question that comes in is whether I want to run extra wires for possible future (or present) upgrades. --wifi boosters, etc that were never part of the original plan.



Unless of course, I'm missing something...

Can't you daisy chain the general use receptacles? Depending on the size of your breaker section it can get pretty tight in there for splicing multiple Romex circuits together, not to mention breaker space. Unless you have room for a 4 square junction box near the panel, and accessible. AWG 12 makes it even worse.

[mrdes8]

AC thoughts... usually one circuit to each side of the trailer, assuming 12ga/20 amp. I like to run a dedicated circuit to the converter/charger. I do run a circuit to the fridge but recently I haven't used it as I run the compressor fridge on 12v all the time. I seem to always have an outlet in the front overhead locker though I have yet to actually use it. I upgrade the panel to the smallest I can get, usually an 8 fuse one. Remember to NOT bond the grounds and neutrals in the box, I always add a separate ground lug. I have never put a new A/C unit on a trailer so I don't have anything to say about that, I'll bet others do. We do have a 2K inverter but rarely use it, we are very low power consumers, no TV, microwave, hairdryers, air fryers, etc., but I could run them all if I wanted.
Good luck, Mark D

[Vernation]

"Can't you daisy chain the general use receptacles?"
"usually one circuit to each side of the trailer"


The original configuration had one receptacle on the front wall, one on curbside, one on the back wall, one on street side.


Since power will be coming from mid-street side, theoretically I could put the street side and front receptacles together on one run. It would be quite the detour to do this with the other two though...


I'm planning for a 12v frig, but it also has the 120v option, so I thought putting in a 120v line for it won't be something that I regret.


I'm glad to hear both of you saying "12 awg" -- This is what I bought. I have read about some people installing 10 awg and was doubting my choices.

[ITSNO60]

Originally Posted by Vernation

"Can't you daisy chain the general use receptacles?"
"usually one circuit to each side of the trailer"


The original configuration had one receptacle on the front wall, one on curbside, one on the back wall, one on street side.


Since power will be coming from mid-street side, theoretically I could put the street side and front receptacles together on one run. It would be quite the detour to do this with the other two though...


I'm planning for a 12v frig, but it also has the 120v option, so I thought putting in a 120v line for it won't be something that I regret.


I'm glad to hear both of you saying "12 awg" -- This is what I bought. I have read about some people installing 10 awg and was doubting my choices.

Noooo you don't want 10 gauge, you will never get it to fit in the boxes. If there are receptacles that will only see light loads like TVs and such even 14 gauge is fine, and easy to work with. Think of box fill, the bigger the wire the less you can fit in a box.

When in business we would normally see 2 kinds of DIY work, either overkill or underkill. I still remember seeing additions wired with #10 UF stuffed into tiny GEM boxes, then on the flip side I saw my share of orange extension cord wiring inside the walls as well. I even saw a main 50 amp disconnect where someone fed it with two pieces of extension cord by twisting all 3 conductors together and putting them under the lugs.

Don't be afraid to use #14 when you know it will never see a heavy load, it is much easier to do a professional looking job in a tight spot with it. Technically only the galley and bath plugs are required to be 20 amps. Usually the outside one will be as well because it is tapped off the GFCI circuit.

There will be those who disagree and want to use #12 everywhere but trust me, 30 years in the business you don't need it everywhere and it can work against you especially in free conductor length and box fill violations. If you plan on a space heater make that one 20 amps though, if you want to run it on high. Hopefully you will be using some sufficiently sized boxes, at least 18 cu inch. For shallow walls a shallow 4 square with a plaster ring gives you far more room than a single gang shallow.

I realize in a trailer there is no 120 volt lighting and very few recaps so it may be easier to just use all #12 since you're there anyway but if you do make sure to use big enough boxes so you don't end up with a hack job.

[Vernation]

@mrdes8
One of the factors I am trying to deal with is using the same wire-routing holes in the ribs.


Since originally all of the power came from the left rear, there are a lot of holes in that area, becoming less as you move away.


I was thinking of putting the power mid-streetside. Mostly for weight considerations. --That puts all of the weight directly over the axle instead of five or more feet behind it.


Now I'm wondering whether I should rethink that placement. I'm not sure there are enough holes to do the job. And making more holes in the supporting structure in order to route more wires seems like a bad idea to me...


How did you overcome this issue?


Perhaps I can spread out the placement of the solar components so that most are over the axle and only some are behind it?

[mrdes8]

Hey, so I am a big fan of electrical, especially the batteries being as close as possible to the wheel well streetside, for weight and length of wire runs. I also try to put a few wire runs in the ceiling and walls as possible. No solar wiring in walls. 110v runs in cabinets and closets etc. Hope this pics helps. Batteries were placed and used to determine the depth the cabinets needed to be. I wouldn't worry too much if you need to do a couple more holes, try to keep them 3/4" or smaller.
Good luck, Mark D

[Zeppelinium]

Ceiling wires:

Taking down the ceiling skin is a two-person job, and even then it's not easy. I cut my [23' Safari] skin into two pieces and put the joint at a rib. In my Sovereign I cut it into three pieces. The joints look perfectly normal and I can manage the skins by myself.

Zep

[Vernation]

"I cut my [23' Safari] skin into two pieces and put the joint at a rib."


Hmm. How did you secure it?: Was there enough aluminum for the halves to overlap at the rib so that you could secure them? or did you put up an extra join piece for them to slip behind?


Most of my wire holes run through the ribs curb-side, not at the ceiling center, more like above the door...

[mrdes8]

One thing I've done on the last couple trailers is to run side to side wiring under the floor instead of up and over the ceiling. I think it uses a lot less wire and keeps those spacious 1 1/2" deep cavities open for insulation.
Good luck, Mark D

[Zeppelinium]

Originally Posted by Vernation

"I cut my [23' Safari] skin into two pieces and put the joint at a rib."

Hmm. How did you secure it?: Was there enough aluminum for the halves to overlap at the rib so that you could secure them? or did you put up an extra join piece for them to slip behind?

I stand corrected. I removed the center light/fan fixture (3 fans in the Safari is overkill-one Fantastic fan and one vent is plentyi), so I had to put a large patch at the location. Turns out I cut the skin into three pieces, so one of the cuts is mostly concealed by the fan patch. The other cut is right through the middle of the air conditioner, so that cut is only visible for about 1.5" one either side of the AC. I used a thin metal cutting blade on a sabre saw, so the kerfs are only about 1/16" wide, not very noticeable.

Zep