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Which side should rough wiring for roof ac be on?

tooldad1041
Explorer
Explorer
We are converting a cargo to toy hauler. We have a donor camper for the AC, fridge, windows, and couch. However the donor camper is an hour away at the lot and the cargo trailer is at the shop where we live.

We are putting the ceiling in the trailer now and can't get to the donor camper until this weekend at the earliest.

All I need to know is should the romex wire be routed to the front or the back of the AC unit? I am not sure the brand, but I'm sure it's a dometic.

I just dont want to drill through the steel trusses when I can route the wire along the wall to the correct side of the AC unit without drilling if possible.
11 REPLIES 11

ajriding
Explorer
Explorer
Good to know solid wire should not crack. Maybe I was mis-informed, or have dated info. I have never seen cracked wire either.
Despite any code, I would not think a heavy extension cord would be more fragile than a solid wire clanking around inside an RV wall. Im not sure what the issue would be,
but it will be a lot cheaper to use house wire than expensive stranded wire…

Dave_H_M
Explorer
Explorer
mine cones into the ac from the front of it.

Use the Bobo technique.

Bobbo
Explorer II
Explorer II
Just leave enough wire up there to reach either end. Cut it off if it is too long when you install the A/C.
Bobbo and Lin
2017 F-150 XLT 4x4 SuperCab w/Max Tow Package 3.5l EcoBoost V6
2017 Airstream Flying Cloud 23FB

cavie
Explorer
Explorer
ScottG wrote:
Use 12awg Romex.


Yes #12 GA on a 20 amp breaker.
2011 Keystone Sprinter 323BHS. Retired Master Electrician. Retired Building Inspector.

All Motor Homes are RV's. All RV's are not Motor Homes.

cavie
Explorer
Explorer
ajriding wrote:
Always on the front on ones I have seen, mostly Dometic
Right or left does not matter as the 3-wires from AC will be kind-of looped anyway and hang in the return air space/cavity. The side that the power is attached will likely be where the knobs are located. If middle then middle, if knobs on the right then route the power there.
If you can come from the front then should be perfect, if from the side then, yes, aim at the front 5 inches.

When you say,Romex, do you mean solid copper house wire?
Generally RVers tend to believe that solid wire will be more likely to develop cracks, but the wound/stranded electrical cord (like a heavy extension cord) will not crack due to vibrations on the road.

I always buy a heavy gauge extension cord (cheaper than buying by the foot) and use that for the AC electrical. Im on 6th camper renno.


120 volt wiring in all rv/s is ROMEX. Flexable rubber cord is only used in movable slides. Wiring is per the NEC. Solide wire does not CRACK.

Just run enough wire to the hole to go all the way around it.
2011 Keystone Sprinter 323BHS. Retired Master Electrician. Retired Building Inspector.

All Motor Homes are RV's. All RV's are not Motor Homes.

tooldad1041
Explorer
Explorer
Yes, I am using 12g romex. Thank you for the front reply. That's all I needed to know. One of the next few weekends we will get to our lot to remove the AC from the donor and install it in the cargo.

The cargo has the frame reinforced around the vent for AC prep. I am a shop teacher. I have taught construction, electornics, and woodworking. I would use either 12g romex or 10g stranded. I chose romex as that is what is in most campers.

We have ran all wiring for 110 v outlets under trailer in 3/4 pvc with junction boxes. None exposed. All 12v wiring is 14g stranded in sheathing and ran on the inside with grommets wherever it goes through the frame to protect from damage.

All precautions are being taken for electrical. Thanks for the answers

ScottG
Nomad
Nomad
Use 12awg Romex.

A1RVTraveler
Explorer
Explorer
The 120VAC wiring need to be at the front of the AC unit.

DrewE
Explorer
Explorer
ajriding wrote:

When you say,Romex, do you mean solid copper house wire?
Generally RVers tend to believe that solid wire will be more likely to develop cracks, but the wound/stranded electrical cord (like a heavy extension cord) will not crack due to vibrations on the road.


Nearly all commercially produced RVs use standard solid household cable ("Romex") for the AC wiring. Wire breakage doesn't seem to be a big problem. Connections working loose are more common, but would be at least as much a problem with stranded wire (for screw terminals). Stranded wire is also not compatible with the self-contained receptacles used in most RVs.

Most extension cord wire would not be approved for permanent installation per the electric code. That doesn't immediately make it unsafe, but it would make it not acceptable per code in most places.

ajriding
Explorer
Explorer
Always on the front on ones I have seen, mostly Dometic
Right or left does not matter as the 3-wires from AC will be kind-of looped anyway and hang in the return air space/cavity. The side that the power is attached will likely be where the knobs are located. If middle then middle, if knobs on the right then route the power there.
If you can come from the front then should be perfect, if from the side then, yes, aim at the front 5 inches.

When you say,Romex, do you mean solid copper house wire?
Generally RVers tend to believe that solid wire will be more likely to develop cracks, but the wound/stranded electrical cord (like a heavy extension cord) will not crack due to vibrations on the road.

I always buy a heavy gauge extension cord (cheaper than buying by the foot) and use that for the AC electrical. Im on 6th camper renno.

wa8yxm
Explorer III
Explorer III
This is a guess based upon the two different makes I have but the Driver's side about 1/4 to 1/3 the way "Back" from the front.

Suggestion: Get A/C, then route wires. that way you put 'em in the right spot.

Suggestion two: Go to A/C maker's web page and shag an installation manual for your hard drive.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times