80 Amp RV Panel (Combination Park Style)

[nsula_country]

I normally respond to electrical posts, not create them...

Have been wiring up the shop. Getting down to the details. We have 2 travel trailers. A 28', 50 amp service, with 1 15k AC (2nd AC ready but not installed, hence 50A service) and a 17' hybrid with a 9-11k AC. Neither travel trailer would ever demand the service rating. Actually the 17' docking station currently is a 20A 1P breaker.

We want to park the trailers under the 30x60 lean off of the shop. Can make two runs and install a 30A and a 50A RV box and 2 breakers and be done.

I'd like to use a park style combination panel with a 50A, 30A, 20A receptacle and is loaded with breakers for each. Requires only one run, one breaker.

Example of Combination Panel
https://www.amazon.com/gp/product/B00A8FQUYW/ref=ox_sc_sfl_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

Question is... Drumroll... Will this actually be considered a sub-panel since nothing hard wires on the load side? It is simply a panel with breakers and receptacles, similar to a portable generator distribution box.

Waiting on the answer those familiar with RV park wiring and/or combination panels.

Thanks,

CT

 

[sberry]

What exactly is it you want to know? It needs to be fed 4 wire if there is another main it is coming from.
The way it looks it could be used as service entrance equipment as it has limited spaces. A common panel may be way cheaper and you wouldn't have to group the recepts, you could tailor their location.
Its priced right.

 

[nsula_country]

What I would like to know is, would this be considered a "sub-panel"? I understand it's a 4 wire. A 50 amp RV box is 4 wire regardless. Shop main panel is 200 amp directly behind meter, bonded.

Question is does this fall under "sub-panel" code requiring a ground rod? If so, how is it different than installing a 50 amp RV box and a 30 amp RV box next to each other?

The travel trailers will be parked next to each other. No occupency, just keeping AC and refrigerators going between trips. Common panel or 2 separate RV receptacle boxes next to each other. No advantage but 1 conduit or 2...

I just don't remember seeing a ground rod at each pedastel at campsites.

CT

 

[sberry]

If its in the same building it doesn't need extra rods.
A detached structure would. While a panel in another building is often called a sub its really a service to the structure from another service and needs some of the elements of a service, disconnects and rods.

 

[nsula_country]

Same 4200 sq/ft slab, but on other side of the wall... NOT DETACHED. That's what I was looking for. Had been studying the NEC 2011 (last one I bought) for the dividing line.

Felt the Combo Panel would be legit with just 4 wires.

Thanks

CT

 

[wyliesdiesels]

So you want to wire it with a 4-wire feeder? Its considered a sub...

 

[malibu101]

My thoughts....

You're feeding it with 4-wire since it needs it. Perfect.

On ground rods-
These are very common at "nicer" campgrounds. I've never seen any of these posts with a ground rod or wire running to one. Just because I've never seen it doesn't mean it's right.

Though, I've always thought it kinda odd that often times on the back of the post (backside of where the electric is) is often a cable and WATER hookup on the same post.

 

[nsula_country]

My thoughts....

You're feeding it with 4-wire since it needs it. Perfect.

On ground rods-
These are very common at "nicer" campgrounds. I've never seen any of these posts with a ground rod or wire running to one. Just because I've never seen it doesn't mean it's right.

Though, I've always thought it kinda odd that often times on the back of the post (backside of where the electric is) is often a cable and WATER hookup on the same post.

My thoughts exactly. Campgrounds across the US have these. Usaully see a 400-600 panel feeding a row of slots or a loop.

Question... is this a non detached sub, requiring no ground rod? Per NEC? IN THE SHOP! IT IS ATTACHED!!

Is this right at campgrounds? They are detached...

CT

 

[66cj225]

A layman's idea- how about drill large hole in wall, run cords inside to outlets. Outlets under different set of rules and secure from tampering. Needs to be vermin proof though.

 

[tyme2par4]

It is considered a sub panel, but if it is on an existing structure that already has ground rods, then it doesn't need it's own ground rods.

 

[nsula_country]

A layman's idea- how about drill large hole in wall, run cords inside to outlets. Outlets under different set of rules and secure from tampering. Needs to be vermin proof though.

THIS WILL NOT occur! A little too layman.

CT

 

[nsula_country]

It is considered a sub panel, but if it is on an existing structure that already has ground rods, then it doesn't need it's own ground rods.

Thank you. Confirms what I thought.

CT

 

[Norcal]

A layman's idea- how about drill large hole in wall, run cords inside to outlets. Outlets under different set of rules and secure from tampering. Needs to be vermin proof though.

Because the NEC prohibits cords being passed through walls, see 400.8(2).

 

[malibu101]

Just asking....
Will this be a non-inspected installation?
I hope you get an answer with backup data although I think I agree that attached to the same structure as the other panel, no additional rods should be necessary.

If it is to be inspected as part of your project.....
This is a knowledgeable question that that your inspection agency should have no problem giving you an interpretation on what they want to see.

 

[nsula_country]

Just asking....
Will this be a non-inspected installation?
I hope you get an answer with backup data although I think I agree that attached to the same structure as the other panel, no additional rods should be necessary.

If it is to be inspected as part of your project.....
This is a knowledgeable question that that your inspection agency should have no problem giving you an interpretation on what they want to see.

No inspection. Existing structure and service.

CT

 

[prostreetamx]

I just built an attached garage with a 100a sub panel. In my area they now require a uffer ground even on attached additions. I also set it up for a RV hook-up. I ran one 6/3 with ground on a 50a breaker. I plan to tap into the 50a RV plug and add a 30a 120v and a 20a 120v receptacles that will be fed from the 50a feed but have separate matched breakers. I only have one RV space so only one plug will be used at a time. It wouldn't hurt to drive a ground rod for your 4 circuit sub panel.

 

[nsula_country]

I just built an attached garage with a 100a sub panel. In my area they now require a uffer ground even on attached additions. I also set it up for a RV hook-up. I ran one 6/3 with ground on a 50a breaker. I plan to tap into the 50a RV plug and add a 30a 120v and a 20a 120v receptacles that will be fed from the 50a feed but have separate matched breakers. I only have one RV space so only one plug will be used at a time. It wouldn't hurt to drive a ground rod for your 4 circuit sub panel.

Ufer is tied to 1st panel (main) with additional, 2x 8' rods.... No ufer outside under lean, but same monolithic slab...

CT

 

[wyliesdiesels]

I just built an attached garage with a 100a sub panel. In my area they now require a uffer ground even on attached additions. I also set it up for a RV hook-up. I ran one 6/3 with ground on a 50a breaker. I plan to tap into the 50a RV plug and add a 30a 120v and a 20a 120v receptacles that will be fed from the 50a feed but have separate matched breakers. I only have one RV space so only one plug will be used at a time. It wouldn't hurt to drive a ground rod for your 4 circuit sub panel.

I have heard that Las Vegas has some weird amendments like that. NOt sure what they think it will accomplish.

Nevertheless, the NEC doesnt require electrodes for anything attached....

 

[nsula_country]

Ufer was developed in the desert... High resistance soil...

CT

 

[wyliesdiesels]

Ufer was developed in the desert... High resistance soil...

CT

yes i know all about UFERs and their history.

Was developed for the army for use in desert.

But when there is already an electrode in an attached structure, adding an additional probably wont accomplish anything in regards to lowering the resistance to earth....

 

[nsula_country]

yes i know all about UFERs and their history.

Was developed for the army for use in desert.

But when there is already an electrode in an attached structure, adding an additional probably wont accomplish anything in regards to lowering the resistance to earth....

Is true. No arguments here.

Ufer does have an interesting history if one wants a Google search...

CT

 

[prostreetamx]

I installed a bunch of different types of uffer grounds for a Nevada Power ground test about 20 years ago. They were doing a long term test to see what would actually work in our soil which has no moisture content at all and driving a ground rod is not an option in many cases due to the layer of caliche that is just below the surface in some areas. That stuff is just like concrete. We have no water table anywhere near the surface. They have added a few more acceptable grounding methods over the years and removed some that used to be OK. The prefered method is a 20'+ length of rebar near the bottom of the footings but not touching the earth. Most other states can still just drive a ground rod due to the shallow water table. A ground rod is pretty cheap insurance if allowed in your jurisdiction.

 

[Falcon67]

Because the NEC prohibits cords being passed through walls, see 400.8(2).

Above that, what I've found with my race trailers is that adapting the RV style cord to a plug on a GFCI circuit usually trips the GFCI. The new trailer does it instantly when you power up anything. Note - I have not gone over the electrical yet to verify all the plugs and light wiring. But the older trailer that I personally wired will set off the "more sensitive" GFCI circuits in the shop.

 

[malibu101]

Above that, what I've found with my race trailers is that adapting the RV style cord to a plug on a GFCI circuit usually trips the GFCI. The new trailer does it instantly when you power up anything. Note - I have not gone over the electrical yet to verify all the plugs and light wiring. But the older trailer that I personally wired will set off the "more sensitive" GFCI circuits in the shop.

I seen what you're saying too.
When I've seen this happen it was because the trailer had a panel in it with the grounds and neutrals together like a main panel. Not separated like a subpanel.

Ground and neutral touching on the load side of a GFCI will trip it.

 

[tarmy]

When I built my garage...I had one of the panels for my friends RV added to the outside. It is off my main 200A garage panel. Works great...no rod...it is treated as essentially part of the system that is in the garage...

A couple things to consider...I also added a water bib...and sani sewer connection. My inspector did require separation for the the water bib from the exterior panel. Not sure why...he said they needed to be 10' apart....no bigge.

The sani had to be 10' from the hose bib as well...

Only reason I bring it up....is that if you are doing like I did...which is to set it up for an actual trailer/RV...then be aware there might be some quircks.

Also, put it where you can use it to run a welder as well...I end up using the RV panel for other things as well.

 

[EOC_Jason]

FFS he's in Louisiana not the desert... If you want to play it safe, drive a single freaking grounding rod in next to where you set up the box and be done with it... It's not like we are taking a huge expense...

 

[Falcon67]

Because the NEC prohibits cords being passed through walls, see 400.8(2).

I seen what you're saying too.
When I've seen this happen it was because the trailer had a panel in it with the grounds and neutrals together like a main panel. Not separated like a subpanel.

Ground and neutral touching on the load side of a GFCI will trip it.

That may be it, I intend to open the panel tonight and check, also test all the outlets. Reading the RV forums shows claims that some AC units may cause trips but that seems odd, it's just another appliance. Interesting that Forest River didn't provide any electrical diagrams of the trailer, or anything about the installed equipment including the inverter.

 

[nsula_country]

FFS he's in Louisiana not the desert... If you want to play it safe, drive a single freaking grounding rod in next to where you set up the box and be done with it... It's not like we are taking a huge expense...

Just an extra $15 for a rod and clamp... Got that.

No inspections. Just code.

Don't really want to Hilti a hole in the slab and have a ground rod to trip over if it's not going to benifit. Already have 2 rods at service entrance.

CT

 

[Norcal]

Just an extra $15 for a rod and clamp... Got that.

No inspections. Just code.

Don't really want to Hilti a hole in the slab and have a ground rod to trip over if it's not going to benifit. Already have 2 rods at service entrance.

CT

A ground rod is not required & no legitimate reason to use one.

 

[nsula_country]

A ground rod is not required & no legitimate reason to use one.

10-4 confirms my understanding of the sub-panel rules.

Thanks!

CT

 

[EOC_Jason]

Don't really want to Hilti a hole in the slab and have a ground rod to trip over if it's not going to benifit. Already have 2 rods at service entrance.

There is your answer, if you would have to drill I wouldn't bother either...

 

[Norcal]

If it was a 8' rod standing proud of the earth, it would not be compliant anyways.

 

[malibu101]

Above that, what I've found with my race trailers is that adapting the RV style cord to a plug on a GFCI circuit usually trips the GFCI. The new trailer does it instantly when you power up anything. Note - I have not gone over the electrical yet to verify all the plugs and light wiring. But the older trailer that I personally wired will set off the "more sensitive" GFCI circuits in the shop.

Did you figure out this problem?

 

[Falcon67]

Have not had time to open the panel again to look. Will try to find the time and report back. I did check all the plugs and they are wired correctly so betting the ground and neutrals are tied at the box. That would seem odd to me since it's a 50A setup using a 4 wire shore cord. We can go 4 wires all the way to the L30 on the genny, or convert to three (30A limit) with the supplied adapter.

Remembering this thread - https://www.garagejournal.com/forum/showthread.php?t=252428&page=2

Post #37 - I wired the other trailer and left the grounds separate, shorted the neutral at the genny.

The new 6500 says:

"Grounding
The generator system ground connects the frame to the
ground terminals on the power panel. The system ground is
connected to the AC neutral wire."

So if the trailer has the ground and neutral tied in the box, I should be able to move the ground to a separate termination and unbond the neutral.

Wonder why they built it like that?

 

[wyliesdiesels]

I would do 4-wire on the trailer with isolated neutral, and BOND (not short which is something entirely different) the neutral to ground on the genny.

This way the trailer can be hooked up to an electrical service if ever desired.

You cant have a bonded neutral in 2 places on an electrical service.

 

[Falcon67]

The genny wiring diagram (Champion #100109) shows the neutral bonded to the ground internally at the unit. It just seems a bit odd that a brand new trailer - 2018 model - would have the ground and neutral bonded in the trailer box - unless that is how they typically wire an RV.

Or, the factory has made a few other "errors" on the build, maybe somebody forgot and bonded the neutral in the panel. Now I gotta go look LOL.

I could see as a "doesn't matter" if most places only provide a 30A three socket "RV" port. I need to run an outside plug on the shop for the thing, a 30A three wire RV socket would save some wire $. I need to walk down to one of the powered pit spots this weekend and see what they put in for power connections. Or ask the commercial electrician that wired it because he runs a high zoot small tire Firebird on spray.

 

[Falcon67]

http://oshaprofessor.com/Portable Generators and OSHA Construction Standards 3-05.pdf

 

[wyliesdiesels]

The genny wiring diagram (Champion #100109) shows the neutral bonded to the ground internally at the unit. It just seems a bit odd that a brand new trailer - 2018 model - would have the ground and neutral bonded in the trailer box - unless that is how they typically wire an RV.

Or, the factory has made a few other "errors" on the build, maybe somebody forgot and bonded the neutral in the panel. Now I gotta go look LOL.

I could see as a "doesn't matter" if most places only provide a 30A three socket "RV" port. I need to run an outside plug on the shop for the thing, a 30A three wire RV socket would save some wire $. I need to walk down to one of the powered pit spots this weekend and see what they put in for power connections. Or ask the commercial electrician that wired it because he runs a high zoot small tire Firebird on spray.

No way can that be correct.

Its a code violation and creates a shock hazard potential.

 

[Falcon67]

Good news - trailer is wired correctly. Neutral bar is not bonded. What I suspect happens with the cheater cord is that it ties the equipment ground and neutral together and that trips the shop GFCI. Haven't buzzed the adapter out, but some of the diagrams on the web show them to tie both hots to one hot. I'm betting it's like that because in testing we've tripped the genny breaker using the adapter. Have since bought the correct "dog bone" for 240V operation.

What I found on the 50A to 30A bone wiring:

I don't have - yet - a 240V RV connection. Have to look in the shop panel and see if there is room for one more 240V run. Shoulda got the 30 space instead of the 20!

 

[malibu101]

Do a continuity test on the cord and I bet you'll find what you described.

Also, if the above is correct, no need to even get out the meter.
Just plugging the cheater cord in (with nothing attached) will cause the GFCI to trip if ground and neutral are connected together in the cord.