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RVing message boards => Boondocking => Topic started by: Nastones on January 09, 2017, 05:08:35 PM

Title: Sub-panel
Post by: Nastones on January 09, 2017, 05:08:35 PM
I guess this falls in the category a dumb question is an UN asked question. Is wiring a AC sub panel in a RV the same as wiring a sub panel in a  residential home.
Title: Re: Sub-panel
Post by: Rene T on January 09, 2017, 05:20:05 PM
I guess this falls in the category a dumb question is an UN asked question. Is wiring a AC sub panel in a RV the same as wiring a sub panel in a  residential home.

It's not a dumb question if you don't know the answer.
Yes, the wiring it is basically the same as a home.
Title: Re: Sub-panel
Post by: SeilerBird on January 09, 2017, 05:23:41 PM
I guess this falls in the category a dumb question is an UN asked question. Is wiring a AC sub panel in a RV the same as wiring a sub panel in a  residential home.
Theoretically yes. You put a breaker into the main panel that has enough amperage to protect the wire that runs between the panels. E.G. If you want a 30 amp sub panel then run a ten gauge feeder wire. You can run as many circuits as you wish from the sub panel providing they are not larger than 30 amps. You could run a dozen 20 amp circuits from the sub panel but you will still be limited to only getting 30 amps total out of the sub panel across all the circuits.
Title: Re: Sub-panel
Post by: Gary RV_Wizard on January 09, 2017, 05:30:49 PM
Yes. The entire RV system is considered to be a subpanel that receives its power from yet another sub-panel, i.e. the power post on the campsite. If you want to add another subpanel to the RV, the rules are the same.
Title: Re: Sub-panel
Post by: tvman44 on January 09, 2017, 05:35:05 PM
Yes the same rules apply.
Title: Re: Sub-panel
Post by: robertusa123 on January 10, 2017, 08:33:58 AM
More or less.    What you doing and why
Title: Re: Sub-panel
Post by: Lou Schneider on January 10, 2017, 12:33:24 PM
Yes and no.  Ground and neutral stay separate in the RV panel, just like any other subpanel.  An RV panel also includes a main breaker to allow you to disconnect power at the panel and to act as secondary protection for the incoming power, either 30 amps or 50 amps.

The reason for the input breaker is to protect the power cord in case the source you plug into doesn't have the proper size circuit breaker, such as using an adapter to plug a 30 amp cord into a 50 amp shore socket.
Title: Re: Sub-panel
Post by: Nastones on January 10, 2017, 02:19:21 PM
@ robertusa123, I am putting a 3 Circuit sub-panel in my RV for a 3000w inverter.
Title: Re: Sub-panel
Post by: robertusa123 on January 10, 2017, 05:55:46 PM
I don't see a problem.    Over kill.never hurts
Title: Re: Sub-panel
Post by: AgilityMom on February 13, 2017, 08:45:42 PM
My doggies and I have a wonderful old van with Refrigerator, Microwave, TV, and either a portable heater or portable A/C depending on season.   We usually plug into the two 20 amp standard 3 prong RV outlets with two 25'  #12 extension cords.  We have never tripped a RV hookup breaker so 20 amps is plenty adequate.  But we are running into lots of places we want to go that have ONLY 30 amp and 50 amp hookups.  So I need to turn a 30 amp hookup into two 120v 15 amp outlets: one for fridge, microwave, tv and the other for either heat or A/C.

I have a 30' outdoor electrical cord with a 30 amp male on one end and 3 #10 wires coming out the other end.  I want to attach a subpanel box with two 15 amp breakers, then come off each breaker with #12 wire to a single standard 120v 15amp outlet.  What kind of breaker box do I need that can be wired as a subpanel with two 15 amp breakers and is as tiny as possible?  A Home Depot, Lowe's, Amazon, or eBay Part Number would be greatly appreciated.  Should I store the subpanel box inside or outside our van?  I could mount it on a stake to put near the van.

Also what is the best/cheapest tester to make sure the 30 amp RV hookup is properly wired?  I want to test the 30 amp RV hookup, plug in my 25' cable+breaker box unit, then test each of the 15 amp outlets before plugging anything in.  Again, a Part Number and source would be nice.

Any ideas or suggestions are welcomed (especially inexpensive/cheap ones).  We are three Shih Tzus and a nice old lady who travel the south for Agility Trials in our wonderful old 1999 Econoline Conversion Van.  And, yes, we have a top-of-the-line smoke detector and I check it every time we hook up our van.  Thanks loads for any help anyone can offer.

Izzy, Bob, Buffy . . . and Mom
Title: Re: Sub-panel
Post by: SeilerBird on February 13, 2017, 08:59:44 PM
https://www.walmart.com/ip/Conntek-RV-3-Feet-Y-Cable-Adapter-RV-30A-Plug-to-2-U-S-3-Prong-Connector-15-20A-with-Light-Indicator/131896787?wmlspartner=wlpa&selectedSellerId=4133&adid=22222222227053590015&wmlspartner=wmtlabs&wl0=&wl1=g&wl2=c&wl3=154966632925&wl4=pla-266381512961&wl5=9012416&wl6=&wl7=&wl8=&wl9=pla&wl10=113500221&wl11=online&wl12=131896787&wl13=&veh=sem
Title: Re: Sub-panel
Post by: JackL on February 14, 2017, 05:00:40 AM
Sure, but if your RV has a 30 amp panel, why not add a completely separate 50 amp, 220 volt panel and have two separate feeds coming from your power pedestal

 I just did that.

Jack l
Title: Re: Sub-panel
Post by: AgilityMom on February 14, 2017, 11:05:43 AM
Thank you for your reply, but the splitter cable you indicate is extremely dangerous in my situation.   I have a VAN, not an RV.  I do NOT presently have a breaker subpanel of any kind so the full 30 amp could flow to my #14/#16 standard wiring if a short or overload occur creating an almost certain fire.  The "5-cent" surge protectors on my power strips would be useless.  A 30 amp circuit requires #10 wire or larger; no #14 or smaller wire can exist on even a 20 amp circuit.  So I have to have a sub-panel with breakers that will trip at 15 amp to protect my van and electrical items.  For RVs with subpanels, splitter cables may be useful.  But for a plain ole van with cables coming from a RV hookup to a power strip, a splitter is extremely dangerous.

Please to anyone:  Do not ever use a 30 amp plug to 15/20 amp plug splitter cable unless you are going directly into some kind of subpanel with proper breakers.

Title: Re: Sub-panel
Post by: SeilerBird on February 14, 2017, 02:13:08 PM
sorry
Title: Re: Sub-panel
Post by: Lou Schneider on February 14, 2017, 02:24:58 PM
Tom, she said her van doesn't have a breaker panel at all, it's just outlets wired directly to extension cords she plugs into the park's outlets.

Using a splitter to split a 30 amp feed to two 15 amp plugs can indeed allow a single branch circuit to draw up to the full 30 amps, at least until something melts or catches fire.

Kudos to AgilityMom for recognizing she has a dangerous situation and for trying to fix it.
Title: Re: Sub-panel
Post by: John From Detroit on February 14, 2017, 05:03:40 PM
There normal "Sub" panel in a House has no main breaker, It is fed off a breaker in the MAIN panel which serves that purpose.. It may, however, have a "Master" switch that turns it off completely.  Also as noted the Ground and Neutral are **NOT** Bonded

the "Main" panel in an RV  WILL have a master breaker (30 or pair of 50 amp)
and in the case of a 30 amp box there is a limit to teh number of branch breakers (3 I think but do not quote me on that) .. But again the Ground an Neutral are NOT bonded.

That's really the only difference.
Title: Re: Sub-panel
Post by: John Hilley on February 16, 2017, 04:44:12 PM
You can use a deep 4" square box with a Busman cover. They are available in combination fuse and receptacle. They fit on a standard 4" square box.

Busman Fused Receptacle Covers
http://www.cooperindustries.com/content/dam/public/bussmann/Edison/Resources/Catalogs/Bus_Edison_Box_Cover_Units.pdf (http://www.cooperindustries.com/content/dam/public/bussmann/Edison/Resources/Catalogs/Bus_Edison_Box_Cover_Units.pdf)

The SOY-B would work for you. Use two 4" square boxes back to back. Mount the Fuse/Switch Busman cover on one box and the receptacles on another 4" square box. Use a chase nipple to connect the two boxes together and a cable gland to bring the 30 amp cord into the assembly.
Title: Re: Sub-panel
Post by: AgilityMom on February 18, 2017, 01:13:17 PM
I thought I had this all figured out, BUT . . .
I have:
    30 foot RV cable Male plug to bare wire
    Square D 30-Amp Main Lug Load Center [ http://www.truevalue.com/product/30-Amp-Main-Lug-Load-Center/9759.uts ]
    Two 15 amp breakers
    #12 Romex
    Old Work Boxes
    Outlets and Covers
   
I planned to attach the RV cable to the Lug Load Center, then come off the 15 amp breakers with #12 romex to two standard plugs.  This should give me two circuits that will trip at 15 amps, one circuit for heater or AC and another circuit for refrigerator/microwave.  The RV hookup is the "panel" and will trip if 30 amps is exceeded and  the Lug Load Center is the "subpanel" that will trip if either of the two circuits in my van exceed 15 amps.

The Lug Load Center has no ground bar (but an apparent screw hole for attaching a ground bar).  What do I do with the ground?  Did Home Depot sell me the wrong pieces?  Do I need a 30 amp breaker --> two 15 amp breakers?  Where can I find a wiring diagram?

This seems so simple, but since I can find no wiring diagram anywhere to confirm my plans, I've got to be missing something.  I'm pretty good with Google and with basic wiring, but I cannot seem to find a wiring diagram anywhere to confirm that what I plan is correct and safe. What assembly do I put on the bare end of my 30 ft/30 amp RV cable to give me two 15 amp circuits in my van?

Thank you all for all your answers ! ! !
Title: Re: Sub-panel
Post by: SeilerBird on February 18, 2017, 01:16:08 PM
Good luck
Title: Re: Sub-panel
Post by: JackL on February 18, 2017, 03:17:06 PM
I thought I had this all figured out, BUT . . .
I have:
    30 foot RV cable Male plug to bare wire
    Square D 30-Amp Main Lug Load Center [ http://www.truevalue.com/product/30-Amp-Main-Lug-Load-Center/9759.uts ]
    Two 15 amp breakers
    #12 Romex
    Old Work Boxes
    Outlets and Covers
   
I planned to attach the RV cable to the Lug Load Center, then come off the 15 amp breakers with #12 romex to two standard plugs.  This should give me two circuits that will trip at 15 amps, one circuit for heater or AC and another circuit for refrigerator/microwave.  The RV hookup is the "panel" and will trip if 30 amps is exceeded and  the Lug Load Center is the "subpanel" that will trip if either of the two circuits in my van exceed 15 amps.

The Lug Load Center has no ground bar (but an apparent screw hole for attaching a ground bar).  What do I do with the ground?  Did Home Depot sell me the wrong pieces?  Do I need a 30 amp breaker --> two 15 amp breakers?  Where can I find a wiring diagram?

This seems so simple, but since I can find no wiring diagram anywhere to confirm my plans, I've got to be missing something.  I'm pretty good with Google and with basic wiring, but I cannot seem to find a wiring diagram anywhere to confirm that what I plan is correct and safe. What assembly do I put on the bare end of my 30 ft/30 amp RV cable to give me two 15 amp circuits in my van?

Thank you all for all your answers ! ! !

First; if you are using 15 amp breakers, you only need no 14 wire
Second, the panel you show does not show the interior, but what you should have coming in from your 30 amp cable is a black (hot) which should go to a main lug which is attached to the bus. A white neutral which should be attached to a lug or neutral bar. and a ground (green) which should be attached to a ground bar.

Then your out going feeds to you receptacles should be attached Black to each of your breakers, white to the neutral bar or lug and the bare ground wire to your ground bar.

Jack L
Title: Re: Sub-panel
Post by: John Hilley on February 19, 2017, 10:13:09 AM
What you have planned should work fine. You don't need a 30 amp breaker, that is in the pedestal you are plugging into. You don't need a ground bus, just connect the three grounds together with a wire nut and an additional ground pigtail that you connect to a screw in the threaded hole you see in the box.

Ground pigtail
http://www.homedepot.com/p/Ideal-Grounding-Pigtail-12-AWG-Solid-Tail-5-per-Bag-Standard-Package-is-4-Bags-30-3392S/203734801 (http://www.homedepot.com/p/Ideal-Grounding-Pigtail-12-AWG-Solid-Tail-5-per-Bag-Standard-Package-is-4-Bags-30-3392S/203734801)