RV Outlet NEC Code Question

[BurbMan]

Hi guys,

I currently have an outlet installed on a pole by where I park the RV. The outlet is a 30a amp RV outlet and is 30a 120v (NOT 240v).



It's fed directly from the panel with #10 wire connected at the main panel to a 30a single pole breaker.


I would like to change out the outlet to a box that has the 30a outlet, along with a 20a GFI and two breakers, one 30a and one 20a, one for each outlet. This is an outdoor weatherproof box like you would see at a campground or RV park.



Reasons for the change are:

1) I like having a breaker so I can plug in the RV and then power it on. This eliminates wear and tear from arcing on the plug.

2) It would be nice to have a convenience outlet there. I can't just add one without it being protected by a 20a breaker.

Ideally I would like to feed this with the 30a 120v circuit that's already there.
Most of the time the RV draws very little power, it's only trickle charging the batteries. It will draw power with the a/c on, so just won't be able to use the conveience outlet at those times. I'm not looking to increase power capacity at the outlet, and I have no need for 240v there, it would be nice to plug in an extension cord without having to unplug the RV.

Can I feed this new outlet with the existing circuit, or is this considered a subpanel because it has breakers? Do I need to feed it with a 30a double pole breaker like it was a sub panel?

I know I "can" wire it from the existing circuit with no issues but am wondering if anybody knows what the NEC rule is on this.

[myredracer]

soren wrote:
Electrical questions are always pretty entertaining on the forum, usually because there are plenty of wrong answers, but this one is in a league of it's own.

I will tell you one thing for certain, I would never ridicule anyone on a forum simply because I did not agree with their opinion, esp. if I thought my opinion is superior because I happened to think I have more training, education, experience or qualifications. And I would never post any comments along with a note that I am a PE (ever...).

soren wrote:
How many of you would expect to find pairs of massive feeder conductors, as in 3/4" diameter wires, bolted inside of a 50 Amp pedestal, with no breaker that size anywhere. How many understand a ten foot tap rule? RV park wiring has lots of things a typical residential electrician might find odd, or even wrong.

As I noted earlier, ALL of this depends on the local inspector, and they may be extremely competent, or clueless.

The OP's initial query is of a pretty basic & simple code nature. How are comments like the above and others you've made helpful in clarifying the OP's situation. I even commented that the OP could go to the Mike Holt electrical forum (where there are electricians, engineers, inspectors and other electrical experts) if he still had any doubts. How many homeowners even take out a permit to install an RV recept./pedestal? Not interested in debating the different methods for wire pulling and when to.

eom...

[enblethen]

Soren:
You may want to look at Art 225 II 225.30

[soren]

stevenal wrote:
Breakers in the box make it a sub-panel. No need for a main breaker in the box for it to qualify as a sub-panel. Install a couple ground rods per code and you're good.

Fail. Specifically, NOT a sub-panel, not treated as such in the code, and exactly why most folks should not be answering questions on topics they know nothing of.

[time2roll]

Kayteg1 wrote:

time2roll wrote:
You can have the city inspect your work if you have any concerns.

I am General Contractor and not expert in electrical, but did electrical in the past.
When I think your technical conclusion is correct, from the experience I can tell the City Inspector does not have to have electrical knowledge, although he might.
What inspectors do is checking out the build with the design, meaning you need to design and have it approved by Building Department for the inspection.
The Dept should have qualified planer who can elaborate on the design in their office.
Codes change from state to state and from city to city, so you can never tell....

Yes in my experience if you want a city inspection the city will require written drawings to review and a fee to be paid before the inspector comes out. And I think the OP will probably get perfectly good guidance if asking nicely at the city permit counter of the building code department.

[stevenal]

Breakers in the box make it a sub-panel. No need for a main breaker in the box for it to qualify as a sub-panel. Install a couple ground rods per code and you're good.

[soren]

Kayteg1 wrote:

time2roll wrote:
Not an electrician but putting that combo TT-30 and 5-20 outlet should not be an issue using the existing 30 amp feed. Nothing wrong with multiple outlets on one branch circuit, the 5-20 has a 20a breaker to limit power so good to go IMO.

Of course it does become easier to draw more than 30 amps and still most sub-panels have more branch capacity than the main feed.

You can have the city inspect your work if you have any concerns.

I am General Contractor and not expert in electrical, but did electrical in the past.
When I think your technical conclusion is correct, from the experience I can tell the City Inspector does not have to have electrical knowledge, although he might.
What inspectors do is checking out the build with the design, meaning you need to design and have it approved by Building Department for the inspection.
The Dept should have qualified planer who can elaborate on the design in their office.
Codes change from state to state and from city to city, so you can never tell....

And this is why, if the OP has a burning desire to install this RV pedestal (or "Stand" in NEC parlance) AND get the blessing of his local code authorities, he needs to figure out EXACTLY what they want to see. The issue is that most here are guessing and making assumptions based on what they know, and understand. Things like how to wire a sub-panel, and that the calculated loads involved are linear, with no factors applied. (As in, "you need a 50 amp feed, since you have a 30 and 20 amp receptacle) Bottom line is section 551 of the National Electric Code deals with RV electrical supply installations and it has little overlap with other types of installations. How many of you would expect to find pairs of massive feeder conductors, as in 3/4" diameter wires, bolted inside of a 50 Amp pedestal, with no breaker that size anywhere. How many understand a ten foot tap rule? RV park wiring has lots of things a typical residential electrician might find odd, or even wrong. The theory and practice is also very driven by the manufacturers of the equipment, and NEC rules can defer to doing installations, "according to manufacturer's instructions".

As I noted earlier, ALL of this depends on the local inspector, and they may be extremely competent, or clueless. A case in point is the poster who discussed how the inspection went on his garage sub-panel installation. Quite literally, several of the code agencies I have done business with would take the information the poster provided, verified it, and fire the inspector. In tough enforcement areas, missing ground rods, unverified trenching, and conduit installation, and other possible violations are not trivial matter. In other jurisdictions, you're lucky if the clown will take the time to drop his Snickers bar and coffee cup long enough to step out of the truck,and take a quick glance, before passing the job.

[Kayteg1]

time2roll wrote:
Not an electrician but putting that combo TT-30 and 5-20 outlet should not be an issue using the existing 30 amp feed. Nothing wrong with multiple outlets on one branch circuit, the 5-20 has a 20a breaker to limit power so good to go IMO.

Of course it does become easier to draw more than 30 amps and still most sub-panels have more branch capacity than the main feed.

You can have the city inspect your work if you have any concerns.

I am General Contractor and not expert in electrical, but did electrical in the past.
When I think your technical conclusion is correct, from the experience I can tell the City Inspector does not have to have electrical knowledge, although he might.
What inspectors do is checking out the build with the design, meaning you need to design and have it approved by Building Department for the inspection.
The Dept should have qualified planer who can elaborate on the design in their office.
Codes change from state to state and from city to city, so you can never tell....

[randallb]

Do it correctly the first time and in the long run it will be a lot cheaper. You can buy a good 50/30/20A breaker equipped RV box for about $120. Add the appropriate size direct bury cable with plastic conduit as it comes out of the ground (this should be legal in most areas but check your local code) and be done with it. You will always find that saving money up front will cost you more down the road. With the job done like you were setting up a new RV park it will last you for the rest of your life and will be there if you upgrade to a 50A RV. I myself always use a 50 to 30 adapter cord to my 30A EMS if the park has 50A outlets in the pedestal. The 50A outlets are always in better shape and much less likely to be burned up compared to the 30A outlet. If you can not afford it right now wait a little while. You will be much happier in the long run.

[wa8yxm]

If you are planing on 30 amps max.. No problem, Just swap the box

If you want to be able to draw the full 50 amps (30+20) you will need to pull new wire.

That simple.

I put in a box like the one you have but only a 20 amp breaker

NOTE: THe code allows a smaller breaker on a bigger outlet.. The other way around however is not allowed in most cases.

[soren]

myredracer wrote:

soren wrote:


What? I've pulled at least a million of feet of wire over thirty years as a licensed commercial/industrial electrician, I have never heard of, or seen, anybody who soldiered a head together, to pull wire. Got to give credit where it's due. Electrical questions are always pretty entertaining on the forum, usually because there are plenty of wrong answers, but this one is in a league of it's own.

Huh... As an EE, having worked with hundreds of elec. contractors over 30 years and having pulled many hundreds of feet of wire myself, guess I don't know what I'm talking about. Not the normal way of doing it, but for a homeowner who may not have the right tools and knowledge and for small wire, won't result in the pull cord separating from the wire being pulled in, esp. in a tough pull.

Have you otherwise got anything positive/helpful to add to the thread with all that knowledge as an electrician?
Guess not or it'd be above somewhere already :R

No I specifically avoid making statements about what the NEC has to say in matters like this, for a few reasons. First, from a personal perspective, IMHO, the OP should just swap out his old receptacle to the new "RV pedestal" and be done with it. If you have ever done these, or done the calcs. and design for an RV park, you know that they are designed as a small distribution panel, and have one, or two feed conductors, a neutral and a ground. In this case, he does not need an additional set of conductors for the convenience outlet, since that's not the manufacturer's intent, or design, as evidenced on the wiring schematic attached to the product., and NEC requirements. Second, any OPINION on the topic by members here, is just that. What is acceptable to the NEC is what ever the "authority having jurisdiction" or local code inspector, has to say on the issue. Now, you or I could go into great detail about the subtle differences between wiring an RV pedestal, and a sub-panel, and why it's in a completely different section of the code. OTOH, the local inspector may have never inspected a pedestal in his life, and only think (incorrectly) that he needs to view this as a sub-panel. So, do I find the need to provide information that could quite possibly be incorrect, since I'm have no intimate knowledge of the OP's local code enforcement situation? No, and neither should any professional, including yourself.

[soren]

MrWizard wrote:
i have a near new fish tape
its only been used one time

in my past working lives, i have twisted, tied, taped, used wire cage pulls, and even steel cable come alongs or electric winches

i would solder them if i thought i needed it, to get them pulled, then cut off the end and finish the install

put discussing how to pull wire, that the OP does NOT need to pull

is not helping him

So, you are helping who exactly, by seconding the brilliant recommendation to solder a head up, to pull wire?

Here is a hint. If you are needing to apply such an EXTREME force, that the only way you could keep a head from pulling apart is to solder the individual conductors together, you are doing something wrong, and probably damaging the conductors. I have, on several occasions, removed and replaced damaged wiring, that was pulled by idiots who couldn't get a pull to move using normal techniques. They then had the brilliant idea to getthe wire moving by lashing the pull rope to a truck, backhoe bucket, etc.... and apply several times the force necessary to do the job.

In case there is any ambiguity to any of this. If you are pulling a few small conductors, say three #8 THHN, in a 3/4" PVC conduit(as was discussed here), you are at roughly 50% of fill capacity, and have no need to solder anything. If you are exerting such force that you are pulling a head apart, STOP and figure out WHY, as you are probably damaging the wires and wasting time and money. There is NEVER a need to solder a pull head together when pulling wire.

[Ralph_Cramden]

Dave H M wrote:
We coded and shmoded, and NEC and NEMA this one all the way to the ozone layer. :W

Coded and shmoded and schmoded again for good measure lol.

How many amps according to the National Electrical Schmode to fire one of these up?

[BurbMan]

So opinion seems to be split here on the exact question that I am asking....

Either:

a) This is a simple 120v outlet box made specifically for RVs that offers a choice of 2 types of 120v connections with local disconnects to prevent arcing at the plug when connecting/disconnecting.

OR

b) The presence of breakers and both 20a and 30a outlets forces us to consider this as a sub panel with 2 branch circuits. I do know that the NEC does NOT allow 120v subpanels, they must be fed with 2 hot legs, a neutral and a ground.

I am inclined to go with (a) because of the following:

1. If this was a sub-panel, it would have a "main" disconnect to shut off the whole panel, not just breakers for the branch circuits.
2. There are no knockouts or other provisions for running cables out of this panel, or for adding additional breakers, so it's hard to consider this a sub-panel if you can't connect anything to it.
3. Given the above, you couldn't utilize 240v from this panel if you wanted to ...existing connections donlt support it and there is no way to create or attach a 240v outlet.
4. This is made specifically for RV use, it's not a general use device.

Speaking of sub-panels and inspections, we just had our new 24x30 garage built and wired in January. The contractor had his electrician come in and wire a 100a sub panel in the garage. It has a single ground rod installed outside the garage, not 2 like what you are saying is now required.

The inspector came and verified that the GFI breakers worked and randomly checked some outlets. He never looked at the sub-panel, the trench to the garage was already filled in by the electrician so the depth of the conduit was not inspected, the inspector never went into the basement to see how the cable was run in the house, nor did he look at the main panel to see how it was connected.

Regarding the cable pulling, I pulled all of the cable out of the conduit except for one #12. Then I twisted all 3 of the 10's together and attached to the 12 I was using as the pull wire. I didn't solder the ends together, but wouldn't hesitate if I needed to.

I set up the 3 spools of THWN on a dowel rod so they could spin, positioned DW there with the lube and told her to squirt some in the conduit about every 6' or wire. Worked like a charm, although I think #8 would have been a bear.

[Dave_H_M]

We coded and shmoded, and NEC and NEMA this one all the way to the ozone layer. :W

I think you have a grip on it Burbman. Go for it.

[Pauljdav]

You will be good since the new box has a breaker. I have the same box as you and I turn off the main breaker I my rv to prevent the arching.