Surface Mount Wiring In Interior?

[WhitneyK]

I know it has been mentioned, but search results where 17,000 + hits.

I'm considering running my wires for my weekender on the inside using those surface mount "railways" with the cover instead of inside my walls. For example: http://www.homedepot.com/h_d1/N-5yc1v/R ... ogId=10053

My thought:
Pros
1. Easier?
2. If I need to get to it I can
3. If I need to add something, it's easier
4. No holes through the floor? into the walls

Cons
1. Doesn't look as neat as running inside walls
2. ???

This will be for 12V & 110V

Please give me your thoughts on this (I said "please")

[Dale M.]

You might consider the "PVC" version of this style of duct.... The metal version is ok but are rigid and will tolerate very little mistakes... THE vinyl (PVC) version is less expensive will conform to irregularities better, in some cases you can do away with some of the corner pieces and and angle turns and just "miter" it to make turn/angle...

http://www.homedepot.com/webapp/wcs/sto ... 005270-_-N

Have used both metal and PVC versions of this duct and unless there is compelling reason to have metal the "PVC" type would be my product of choice....

I think it comes in a dual version that has a divider so you can have 120v AC and and "low voltage" in same "duct" but it kept separate by a divider.... Anyway there is LOTS of configurations of the PVC version out there.... Research well and you may be surprised....

Dale

[doitright]

The only thing I can think of is do not run 12 v and 110 v wire in the same conduit. Only problem with this type race way is keeping it grounded. If a nick on a wire happens and a section would be charged it may not blow the breaker until it becomes grounded by like your hand touching it and also another section that is grounded. Ouch
doitright

[Miriam C.]

You can run surface mount and be fine with it. You should not however, never play with swords or other sharp objects so you don't cut through the pvc... Just kidding guys.

The other thing you can do is hide it behind wood trim!

[Larwyn]

So, what happens when you mix AC and DC circuits in the same duct?

[parnold]

I notched out some wood and covered my wires with that. The wood was then stained to match the interior. You can even plan your runs to look like intentional decorative "chair rails" type of thing.

Looks better than commercial wire run stuff IMHO.

[Miriam C.]

So, what happens when you mix AC and DC circuits in the same duct?

If you let the smoke outta one you let the smoke outta both and one has a whole lotta smoke....?

[WhitneyK]

Dale, yes I was planning on the plastic type of duct. I couldn't think of the proper terminoligy at the time and the link I used was the first thing I came across, just as an example. I recently purchased some for work that was 2 piece plastic, 5' was only like $4. The dual / split duct would be good too.

Did also think about running along the top edge and doing a mini crown molding. Paul has a good idea with the chair rail or just routed wood strips.

The wire I am considering using in my frugal attempt at this build is to use the 14 ga stranded well pump wire (I have a wooden spool of it).

1. 14 ga should be heavy enough for the 12V & the 110V (not planning on operating much with the 110V; laptop, maybe a light, if I use a small microwave or other small appliance, it would be plugged in at the source where the shore wire come in)
2. I understand that stranded is the better choice for trailers
3. My well pump wire is double insulated (thickness) for use in submerged applications
4. It is already paired (like speaker wire) with one of them being marked, and I have access to the 14/2 (3 wires) well pump wire for the 110V

I appreciate the input I'm getting, keep it coming. So the biggest issue is looks.

And, like Larwyn asked, "so, what happens when you mix AC & DC in the same duct?"

I understand about AC & the interferance with Cat5, but is there a "bleed over" with AC / DC?

[Miriam C.]

snip,snip
The wire I am considering using in my frugal attempt at this build is to use the 14 ga stranded well pump wire (I have a wooden spool of it).

1. 14 ga should be heavy enough for the 12V & the 110V (not planning on operating much with the 110V; laptop, maybe a light, if I use a small microwave or other small appliance, it would be plugged in at the source where the shore wire come in)
2. I understand that stranded is the better choice for trailers
3. My well pump wire is double insulated (thickness) for use in submerged applications
4. It is already paired (like speaker wire) with one of them being marked, and I have access to the 14/2 (3 wires) well pump wire for the 110V

I appreciate the input I'm getting, keep it coming. So the biggest issue is looks.

And, like Larwyn asked, "so, what happens when you mix AC & DC in the same duct?"

I understand about AC & the interferance with Cat5, but is there a "bleed over" with AC / DC?

May I suggest if you are using the same wire for both the 12vdc and the 120 AC that you consider some form of marking the wire! If you ever do have an issue you will want to know which is which. Or run them on opposite sides of the TD and leave instruction for who ever may need to know.

As for running them together.....if you were running them outside where there is a decent chance of damage I would tell you to run them on different sides. Inside knowing the difference between them is more important. And if you let the smoke.......

[Larwyn]

I have ran many miles of control cable in electrical substations. We always ran the 125VDC wires in the same conduit as the 120VAC. In fact AC and DC were often ran in the same multi conductor cable. We did avoid running current transformer circuits in the same cable with anything else but even that was usually in the same conduit. Most people will never be involved with wiring current transformers.

The manufacturer of your battery charger, if you have one actually put AC and DC circuits in the same box. Same goes for most any electronic device that plugs into the wall, as even though they plug into an AC wall outlet to get their power, that AC is immediately stepped down and converted to the DC required by the electronics inside.

Though less common, there are cases where AC and DC are run in the same wire. There is no ground reference and the the zero crossing of the AC sine wave rides on that DC reference. You would never notice unless reading the voltage with an oscilloscope as a voltmeter would simply read either the AC or DC component depending on which is selected.

Mixing AC and DC in the same conduit is much the same as mixing chocolate and peanut butter on the same biscuit, only not as tasty.

Generally it is excessive current that pushes the smoke out of the wires.

[Miriam C.]

yeah but who wants to repair both systems if one goes puff!

[WhitneyK]

Auntie M, I agree with the marking of the wire, however, I figure the 2 wire will be DC ( + / - ) and the 3 wire will be AC ( + N G ).

When I refer to running the wire on the "outside", I mean on the interior surface of the unit rather than inside the walls.

As far as getting nicks & cuts in the wire, I'll be performing my chainsaw juggling act on the outside of the trailer. Doesn't look to dramatic when you are only juggling 4' high, the camper is only designed for 2 & my wife doesn't like me running the chainsaw in the bedroom. Seriously?, all wiring will be ran through some sort of "conduit", and I use that term loosely because I haven't determined what material to use yet. Again, in trying to be frugal, I'll probably route some wood to run it through, since I already have wood.

Easier to access wiring when I change my mind (I hope the new one works better) about where I want something.

Mmmmm, chocolate & pb bisquit, mmmmmmmmmmmmmmm, I think I'll go eat something (always looking for an excuse)

[starleen2]

Here are some picture of a camper that I built using the PVC snap enclosures. My walls were ¾ inch thick and I didn’t feel comfortable running the wires in them.

[Engineer Guy]

The Surface Mount idea works well, and the flexibility of it is nice. Routing out Wood, or using prefab 'stuff, is likely 'equal', but the Wood looks nicer IMHO. I've run Wire 'too far' in order to get it inside Cabinets, or behind Baseboards. One implementation I saw at a Biz Pal's new House in the former E. Germany was to build her 5 Floor Biz/Residence like the proverbial Brick Outhouse, with all Walls of Block and Concrete. Then, they route out 230 VAC wire runs w/Concrete dust flying; insert Romex Cable; and plaster smooth over it while finishing the Walls. Std. practice there that cracked me up for some reason...

There's usually unprotected 115 VAC Romex Cable by the workings of any Trailer Fridge Plug in the exterior Hatch - and other places - so safety is a concern that need not be overdone.

Having seen 1st person the curve of the Earth over the Atlantic on a clear day, Earth curvature is not a myth. Neither is interference, whether experienced personally or not. Interference is not a given; it's a possibilty. If I could predict the future - including what's going to happen any given wiring scheme - I'd be at the Track betting on the Ponies instead. Read up on 1st person accounts of various problems at some of the Big Rig Sites, or on other Camper Build Sites.

http://www.rv.net/

http://www.irv2.com/forums/

Manufacturers also readily admit to non-pure-Sine Wave Inverters creating interference on TVs; Radios; and other equipment. This is no myth; it's quite real. Dimmers and power-controlling devices also can create 'hash' interference.

I think your Wire marking scheme will work out fine, and there likely won't be crosstalk interference if equipment that creates it is not used. Self-evident, eh? Here's some Real World scenarios...

Items like Cell Phone Chargers, or PC Power Supplies, are smaller because they're 'switchers'. They turn on-and-off rapidly depending on the load demands of the equipment connected. DC Switcher interference is why 'toys' that output such noise must be turned off in Airplanes at critical times so that Avionics and Control Systems guiding the Plane are not affected.

http://brneurosci.org/interference.html

'Antenna 101' practice tells us that wires run in parallel are the 'best' at exchanging signal on those wires through air, including interference.

When at a Campground, and on the same Secondary Feeder side of A.C. at the Post, noise produced by adjacent Campers can bleed into your Rig via the wiring. The source can be all sorts of Electronics, or someone using corded equipment, like a Drill. This then cross-feeds onto DC circuits, very possibility with no ill effects. It all depends on what you're operating/listening to. I certainly hear/see my Trailer 'Shur Flo' Water Pump in simplistic A/V equipment when it kicks on.

Add-on Filters MAY correct problems after the fact; sometimes not. Twisting the DC Wire pair is very old technique to have any interference induce into both Wires simultaneously, and cancel out somewhat. Wire pairs in Cat 5, and similar Cables, twist pairs for the well-known reasons above. Twisting is an extra cost step in Cable Manufacturing that would be avoided if it were prudent to do so.

It's acceptable Code practice to, say, mark one of two 230 VAC legs with red tape at both Wire ends, even when both Wires are black. If you distinguish your AC/DC Wiring by some similar, rigorous manner, I would guess you'd be fine. Good Grounding - perhaps to a Grounding Block - and a 115 VAC GFI or two should provide adequate safety.

In a past Thread, we discussed the Trailer/Vehicle +12 VDC protocol where Black is + and White is -.

Lots of folks cite personal experience and confuse it with some over-arching Universal Rule. If YOUR Plane doesn't crash, flying is safe. If it does, flying is not.