1978 MC8 - Wiring Ideas

[PNWorBUST72]

So I am getting to the point where I need to make some decision about floorplan and running electrical.

I am trying to decide if I want to run armored cable through the bays to feed my AC side, run conduit on the inside wall since I am framing it with 2x4 or running AC down the center channel.  My OTR AC is out so that whole channel is open...with the exception of maybe the front AC line.

Is the marine 12/3 fine stranded really needed or is it just the premium choice?  Would that apply if I am running conduit for all the runs?

DC/12v is going to run in a channel above  the windows.  AC low DC high...again fine stranded single wires?

Pics of your rides would be helpful... 

[chessie4905]

You could consider uf underground rated wire. It has a tough outer cover that, frankly is a little bit of a pita to strip the ends but not majorly. Many demand stranded, but if wires are properly supported along the way, I havent seen actual issues of any significance. Let the flames begin.lol. You could use stranded thhn and enclose it in plastic or asphaultic loom. Thhn is available at Lowes and Home Depot. Consideration using  other colors for the load carrying conductor, black, red,yellow,etc, except for neutral(white) and ground(green) if you have several circuits that are used for different purposes. I think most just use the black, white, bare or green though. For low voltage wiring, stranded conductors, colors and extra wires the length of coach for future updates/changes. If you encase these in plastic loom, get a different color loom to differentiate from AC loom if used for other wiring. Don't forget to allow a little slack. You can secure loom with Zip ties in tunnel. Make them snug but not so tight that they severely distort loom.

[richard5933]

Not sure if armored cable necessary - might make it really difficult to run through the many tight spaces you will be running things. Perhaps for the leads going to the appliance itself, since that would be unsupported for a short bit, but even that seems like overkill. The majority of the cables are going to be secured to something which eliminates a lot of the stress on them. Those not fastened to a bulkhead or structure can be zip-tied together to make a strong bundle. Someone saw my work and asked if I owned stock in the zip-tie company -  I'm not shy about using them and they do keep things neat and secure.

Invest in some good material to use to wrap/protect your harness as it pulls through bulkheads or around corners. Ours uses lots of heater hose for this, as well as something that looks like fire hose. They fed the lines through these before connecting, and then anchored things down tightly. This prevents the rub points that will become a failure in the future.

Ours has marine cable running throughout. Looks like romax but much more pliable and easy to run.

Whatever you use, be sure to run extra cables in various places for future expansion. At least a few DC runs going nose-to-tail, and at least a couple of 120v runs to each of the major junction points or access hatches.

[PNWorBUST72]

Do you have pics of a post of your build by chance? 

Also, is there a need for special ends to use outlets?  I saw a youtube video when a guy used marine tinned stranded but he said the ends wont provide a solid connection in an outlet.

Suggestion on good crimpers. tools and hardware?

[Bill B /bus]

For the DC side run #10 wire to a  terminal board for distribution at that area. For instance forward by driver's area, living room, kitchen, bathroom, and bedroom.  You'll need 12V for additional items in the bays and engine compartment,  I use a bus bar with multiple  overcurrent  devices (circuit breakers)  in the overhead of the first bay near the battery bank.
With this system you know where your power source for every light, fan, etc without having to remember how you wired it.

Bill

[chessie4905]

Use switches and recepticles that clamp the wires instead of holding with screws. You could probably loop the wire ends for screws and apply solder to keep it from fraying, but I prefer the clamps instead.

[PNWorBUST72]

For the DC side run #10 wire to a  terminal board for distribution at that area. For instance forward by driver's area, living room, kitchen, bathroom, and bedroom.  You'll need 12V for additional items in the bays and engine compartment,  I use a bus bar with multiple  overcurrent  devices (circuit breakers)  in the overhead of the first bay near the battery bank.
With this system you know where your power source for every light, fan, etc without having to remember how you wired it.

Bill

Sorry Bill, you lost me.  Pics maybe? 

[PNWorBUST72]

Use switches and recepticles that clamp the wires instead of holding with screws. You could probably loop the wire ends for screws and apply solder to keep it from fraying, but I prefer the clamps instead.

I like that idea better, is there any downside to those style outlets?

[PNWorBUST72]

This wire is crazy expensive...

https://www.amazon.com/AWG-Triplex-Flat-Marine-Wire/dp/B01M8NWF7K/ref=sr_1_12?ie=UTF8&qid=1550341430&sr=8-12&keywords=marine%2Btinned%2Bfine%2Bstranded&th=1&psc=1

[PNWorBUST72]

For the DC side run #10 wire to a  terminal board for distribution at that area. For instance forward by driver's area, living room, kitchen, bathroom, and bedroom.  You'll need 12V for additional items in the bays and engine compartment,  I use a bus bar with multiple  overcurrent  devices (circuit breakers)  in the overhead of the first bay near the battery bank.
With this system you know where your power source for every light, fan, etc without having to remember how you wired it.

Bill

Bill - Do you mean mount these in each area vs a larger one in a central location?

https://www.amazon.com/dp/B01BV1MS1K/?coliid=I3GK1C1C4LCN7G&colid=18O78BGDAS6YV&ref_=lv_ov_lig_dp_it&th=1

[buswarrior]

Lost a post to the nether regions...

I am a strong supporter of oversizing the circuits with potential for high current.

12 gauge for anywhere that a busnut is likely to try plugging in an electric heater, and for the HVAC.

As for how to connect to devices, see what the wire manufacturer says...

Good quality crimped connectors. Buy a ratcheting crimper and never look back.

I prefer to buy my electrical stuff at the big electric supply house, and pay whatever I have to pay. Name brand, expensive and ordered once.

Little risk of getting junk. I have quite a supply of internet sourced crap for the grandkid to play with now... simply dangerous...

Big box store stranded cable hardly counts as stranded...pretty big gauge of individual strands... defeats the purpose of using stranded.

So, you spend a few hundred dollars more on quality materials, heck, even over pay a few hundred more than some online source... In the end, so long as you've got quality goods, who cares?

Happy coaching!
Buswarrior

[PNWorBUST72]

I like the approach Buswarrior!  I agree.  I dont mind paying money for the right product is all..

Am I looking at the right type of stuff for the AC side here?  12/3?  The wire I linked the right type? 

If I go that route, would it be better to run conduit throughout?  I am thinking the unions between the pipe and the boxes is stronger therefore removing chances of the wire bouncing around and causing issues.

[richard5933]

If I go that route, would it be better to run conduit throughout?  I am thinking the unions between the pipe and the boxes is stronger therefore removing chances of the wire bouncing around and causing issues.

Not sure that conduit is necessary unless routing through an area that will see exposure to elements or at risk of damage. A well-planned wire chase on each side of the bus will be able to carry much of your 120v wiring. Try and plan for access at a later time - it will probably be necessary.

There are a few things about the Custom Coach electrical system that are questionable, but they did a great job of providing a way to get to the wires. May involve lots of screws and pulling a panel or two, but every stitch of wiring is accessible. They also used top quality cable and nearly 50 years later it's still in great condition.

[Jim Blackwood]

***** THHN is not suitable for automotive use! *****

It uses a double layer cheap vinyl insulation and in an unprotected environment the outer clear layer will rapidly deteriorate and split off, leaving only the inner layer to insulate the wire. In addition, the individual strands are of a larger gage size making the wire less flexible and more prone to breakage from movement or vibration. THHN is intended for use in metallic conduit runs and in stationary equipment controls, not the harsh environment often encountered in automotive applications. Do yourself a favor and buy the correct wire. The cost is generally about the same for standard vinyl insulated automotive wire. Better still, use the cross-linked wire that has been a standard in OEM applications for the last 3 decades. It is more expensive but what costs more, better insulation or a fire?

Jim

[buswarrior]

If you enjoy using conduit, run enough for future expansion.

A wire chase, as noted, is easier.

Nobody plans to drive a screw into a cable... trim it too short... carve the insulation off at the quick...but everyone finds a way... whatever you choose, will you be able to pull out and replace the ruined conductor, or run enough spares?

Protection against rubbing thru the insulation in a vibrating vehicle is often done poorly by busnuts. Securing against movement and not burying the methods, so you can re and re is a trick.

Plans change, we forget something, new tech comes along... how resilient will your install be to changes?

Happy coaching!
Buswarrior