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Old 01-19-2021, 08:52 PM   #1
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RV Electrical Wiring Advice

Question First: does anyone know of any reason I can't or shouldn't use a 12g extension cord in place of 14-2 Romex?

Why:
I'm getting ready to run wiring for an inverter project. According to Cavie, long runs of 120 are more efficient than long runs of 12v. Makes sense to me.

The RV is factory-wired with 14-2 Romex to the 120 outlets. I want to mount the inverter next to the entry steps (batteries) and make 120 AC/Out runs to the power panel in the bedroom.

I have a clean path along the passenger side wall all the way from the entry steps, where the inverter will be, to the bed support wall on the right. The factory wiring makes a hard right angle at that point to the foot of the bed where the power panel is. That's where I get stuck.

I'm trying to avoid diving down into the storage compartment if I can help it, keeping it all inside like the existing wiring. I'd have to drill upward from the compartment and unfortunately there are water lines in the existing run for low point drains. Definitely don't need that trouble.

I thought maybe a 12g extension cord would be easier to fish through that 90d turn. I thought of sneaking a snake along the bed support wall, following the existing wiring but it's so tight back there (up against the wall), I don't know that I can grab it from the outside. The second pic is the bed support wall and the 90 is made right after it passes through that hole.

I actually don't have the step-up into the bedroom shown in the floor plan.
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Old 01-19-2021, 09:19 PM   #2
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If it was me, I would snake a fish tape back to the 90. Hook the wires to it and pull it back to the steps. Then work the other way.
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Old 01-19-2021, 10:25 PM   #3
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You could use 12-2 w/ground cord, use a SO or SJO type jacket. This is stranded wire and much less stiff than Romex. Since this is stranded wires, have to either have the proper termination where you are landing it on both ends or use a insulated crimp ring terminal on each end.

Most slides outs have SO or SJO cord when they need to get power into the slide and need something that flexes with movement.

Note that runs of less than 50' of wiring that is rated for the maximum amperage don't occur that much voltage drop on 120AC. Unless you are loading at the 15AMP level for the 14-2 forever you will never notice.
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Old 01-20-2021, 12:28 AM   #4
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Thank you

Thank you both for your feedback.
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Old 01-20-2021, 02:38 PM   #5
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Last summer I installed a Dirt Devil Central RV Vac. After thinking I was going to tap into an existing 15-A circuit I had another idea.

My Xantrex Freedom X Inverter was in one of the ourside storage compartments under the area where I intended to mount the van unit under one of the dinnette bench seats. There was already an hole in the floor for other wiring. I purchased the optional 20A GFCI outlet for the Xantrex Inverter (easy 2-minute installation). I then bought about 6' of 14/2 SOOW cord and then installed a male plug end, ran the other end through the hole in the floor after poking a hole in the foam insulation and then installed the female receptacle and sealed up the hole with more spray foam.

I plugged in the central vac and it works great. The wire does not even get warm to touch when running the vac for the typical 5 - 10 minutes it tales to clean the coach.

I also got the added bonus of being able to run the vacuum without shore power or without running the generator since I am tied into the Inverter.
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Old 01-20-2021, 04:05 PM   #6
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Quote:
Originally Posted by The_Breeze View Post
Question First: does anyone know of any reason I can't or shouldn't use a 12g extension cord in place of 14-2 Romex?

Why:
I'm getting ready to run wiring for an inverter project. According to Cavie, long runs of 120 are more efficient than long runs of 12v. Makes sense to me.

The RV is factory-wired with 14-2 Romex to the 120 outlets. I want to mount the inverter next to the entry steps (batteries) and make 120 AC/Out runs to the power panel in the bedroom.

I have a clean path along the passenger side wall all the way from the entry steps, where the inverter will be, to the bed support wall on the right. The factory wiring makes a hard right angle at that point to the foot of the bed where the power panel is. That's where I get stuck.

I'm trying to avoid diving down into the storage compartment if I can help it, keeping it all inside like the existing wiring. I'd have to drill upward from the compartment and unfortunately there are water lines in the existing run for low point drains. Definitely don't need that trouble.

I thought maybe a 12g extension cord would be easier to fish through that 90d turn. I thought of sneaking a snake along the bed support wall, following the existing wiring but it's so tight back there (up against the wall), I don't know that I can grab it from the outside. The second pic is the bed support wall and the 90 is made right after it passes through that hole.

I actually don't have the step-up into the bedroom shown in the floor plan.
Thor uses flexible wire in the slides for 120 Volts. They use 14-3 SOOW, 9 strand and is rated for 15 amps at 90 C. Romex is only used for rigid wiring. Solid wire is uses where ever possible because it is easier to hookup and does not require any termination. For your application SJOOW cable would be my recommendation.
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Old 01-20-2021, 04:53 PM   #7
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I'm surprised that the RV industry has not adopted marine wiring specs. Marine romex is twisted wire which handles movement much better that household solid wire romex.
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Old 01-20-2021, 07:08 PM   #8
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Here is a picture.... get it at Lowes, HD, most anybody with electrical supplies.
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Old 01-20-2021, 07:24 PM   #9
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Thanks again

I'm going to Harbor Freight and/or Lowes tomorrow to judge the thickness of SOJ wire and pick up a fish tape. It's an hour away but the ACE down the road has the 14/2 romex and no SOJ. I only have my finger to make an educated guesstimate about the diameter of two runs. Oddly enough, the shape of the romex (flat) would give me the room but SJO's flexibility makes it the easiest to use for that 90d bend. If it wasn't for that one obstacle, I'd be free and clear and it would be done by now. I need one run from the transfer switch to the inverter (AC in) and then from the inverter back to the power panel (AC out).

I have to watch the diameter because I need 2 runs and don't know if I can open the hole in the bed support and shower wall wide enough to fit two runs. It's not that I mind making it bigger, but getting to it is a completely different question. If I put the slide partially in. I can get my hand back behind the end piece but not the leverage I need to widen the hole. On the other hand, fighting with Romex to make that turn will be [your opinion here].

I go to sleep and wake in the morning with this stuff in my head. LOL.

Thanks for all your help and suggestions.

p.s. the Walmart down the road has 14-3 extension cord. I had to say hmm. Sure would save some road time but says 13Amps
https://www.walmart.com/ip/Hyper-Tou...Cord/842431456
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Old 01-20-2021, 07:59 PM   #10
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Oh.. extensions cords are not the same as SJOOW. 14/3 SJOOW is rated 18 Amps, extension cords are rated as a stand alone device.
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Old 01-20-2021, 08:12 PM   #11
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I have to admit, the thought crossed my mind. A man can dream, can't he?

Off to Lowes tomorrow. Their wire is 1/4" where HD is 3/8" and I need all the room I can get. Two 25' runs and I should be well on my way to phase 1. If I can figure out a way to make both pulls at once, I'll be dancing in the street.
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Old 01-21-2021, 10:51 PM   #12
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"...the proper termination where you are landing it on both ends or use a insulated crimp ring terminal on each end"

Does anyone know the proper term for the cable terminators required to simulate romex? The inverter is expecting romex.

Thanks in advance.
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Old 01-22-2021, 01:01 AM   #13
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Quote:
Originally Posted by The_Breeze View Post
"...the proper termination where you are landing it on both ends or use a insulated crimp ring terminal on each end"

Does anyone know the proper term for the cable terminators required to simulate romex? The inverter is expecting romex.

Thanks in advance.
Depends on the type of connection push pin or screw. The crimp type connectors come in bullet, ring and fork types up to 10 awg. Personally I would use an insulated solid wire pigtail and a solder filled butt connector. Waytek Wire has all the connectors you could want.
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Old 01-22-2021, 01:54 AM   #14
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this thread will give an electrician nightmares
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Old 01-22-2021, 02:04 PM   #15
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Witricity

Quote:
Originally Posted by cavie View Post
this thread will give an electrician nightmares
I agree!
Now, if only the Americans would give China (or let them steal) the Tesla technology, they could make miniaturized and affordable versions of his power transmission ideas and maybe these could be used in RVs. No more hard-wired headaches!
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Old 01-22-2021, 02:32 PM   #16
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Quote:
Originally Posted by cavie View Post
this thread will give an electrician nightmares
but you don't explain why?
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Old 01-22-2021, 03:26 PM   #17
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Using extension cords or one of the various flexible cords in the OPs suggested manner is NOT to code. Using it for slide power is (when done properly).
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Old 01-22-2021, 03:32 PM   #18
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Using extension cords or one of the various flexible cords in the OPs suggested manner is NOT to code. Using it for slide power is (when done properly).
Thanks. That's at least a partial answer but what does the code attempt to prevent by requiring Romex over SJO? Is it the length of the run, heat, what?

I don't see myself making that bend with Romex and don't have the luxury of having everything out of the way like Thor did when they wired it.
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Old 01-22-2021, 04:18 PM   #19
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SJO is not robust. When the cable just lays around I think ozone or UV attacks the insulation to the point it just crumbles when it ages. But I do not make the rules, heck, it is hard enough to read the rules!
Found this on a OSHA site:
Under what conditions might the use of flexible power cords as permanent wiring be an acceptable/permissible use of flexible wiring? Response: In accordance with 1910.305(g)(1)(iv)(A), unless specifically permitted otherwise in section 1910.305(g)(1)(ii), the use of flexible cords and cables is prohibited as a substitute for the fixed wiring of a structure. Section 1910.305(g)(1)(ii)(A) through (L) provides ways in which flexible cords and cables may be used; and section 1910.305 (g)(1)(iv)(A) through (F) provides ways flexible cords may not be used.
Just finding it gave ME a headache....
You have to think of insurance coverage too...
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Old 01-22-2021, 04:27 PM   #20
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Here is the Standard (1910.305) I refer to above.
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