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jxjcksn's avatar
jxjcksn
Explorer
Mar 15, 2014

Confused about wiring my Recent Purchase

Good evening guys and I hope you all can help me. I have gleaned a wealth of knowledge so far but have come here for the advice from people that know RV's.

Story ....
Moving into an RV for 4 months whilst house sells.
Have an OLD Barn / Shed building which has power 200ft from main building, however, was wired ages ago and hence only has an old breaker panel with 3 feeds 2 Hots and a Neutral/Ground. This panel runs off the main, so I suppose by old standards would be called a sub main. By today's standards should be a sub panel, however, it has no Ground Poles around the barn, hence not really a sub panel and not to current code. All the grounds / neutrals for the lights and sockets in the panel for the barn are joined together into the one bar at the bottom of my Sqaure D Panel.

I am moving an Travel Trailer in there next week and have to get the electrics sorted this week. I spoke to 2 electricians and both explained that what I had was NOT uncommon and what they did in Those Days.

After much reading and research I asked should I strip the old panel out, and purchase a Sub panel with separate neutral and ground bars, sink 2 8ft ground rods to spec for the new box, and rewire all the grounds and neutrals to the new box. i.e. neutral bus isolated from grounds and old grounds would be tied to box and 2 new 8ft ground rods.

They both said that this was unnecessary, AS LONG AS I was sure that the neutral bus bar was in good condition and that I was sure that the wiring in my USED trailer was in good condition. I understand that with codes and safety now it is required to provide a separate ground circuit at a sub panel, however, being as old as the barn is, would it be possible or sensible at all to wire the trailer up, once all checks made to existing wiring, to my existing barn panel as it stands just now.

I'm running way over budget for this project and need to know what I have to do and what is possible. Safety is paramount ! I will do what I have to do but am getting confused with what electricians say and what I have taught and know myself and what I have researched.

Your advice would be most welcome guys.
Use existing Panel .. or complete rewire ?

Just had 4 truckloads of gravel laid for the trailer, going through my orientation next week and delivery withing 1.5 weeks.

Background....
Mechanic by trade, good overall knowledge of electricity and wiring.
Don't like doing things in halfs, don't complete projects or DIY unless researched to death and 110% comfortable !

PS. This is my First RV / Travel Trailer
PPS. Thanks in advance for any replies

27 Replies

  • wa8yxm's avatar
    wa8yxm
    Explorer III
    This may not be code. but personally.. I would leave the old panel, run a 50 amp line to the outlet for the RV, and drop a ground rod (10 foot driven in the ground with at least a 12ga wire (I would use 10) to the green screw,, (Oh and I'd use a green wire). and not worry about the rest of the already installed stuff in the barn. I mean. If they want to bring it up to modern code (Technically it was likely code when it was done and thus still is) they can.. But that is how I'd do it.
  • Do you need 240v? Consider repurposing one hot for the ground. New panel or add a ground bus to existing.

    When money permits, pull new wire.

    Honestly I would just use it as is without changes.

    If the buyer asks just tell him it has always been that way and he can update anything he likes once the purchase is complete.
  • You cannot connect ground and neutral together at two locations. The neutral at the sub panel location must be insulated/isolated from ground.
  • KD4UPL wrote:
    If I understand correctly you've got a 3 wire feed from the panel in your house to the one in the barn. 2 hots, 1 neutral, no ground. This is perfectly acceptable and was allowed by code until recently.
    However, this arrangement was always required to have a ground rod or two at the barn. There was never a time where it was allowed by code without ground rods.
    There's no reasons to worry about the lack of a ground wire from the main panel. Just drive your two ground rods and hook the wire to your existing neutral bar. Make sure the neutral bar is bonded to the metal can of the panel.
    If your neutral and ground are not bonded in the barn panel you really don't have a ground that will clear a fault.
    Install the proper outlet and plug in the camper. It will work fine.


    x2

    Dusty
  • If I understand correctly you've got a 3 wire feed from the panel in your house to the one in the barn. 2 hots, 1 neutral, no ground. This is perfectly acceptable and was allowed by code until recently.
    However, this arrangement was always required to have a ground rod or two at the barn. There was never a time where it was allowed by code without ground rods.
    There's no reasons to worry about the lack of a ground wire from the main panel. Just drive your two ground rods and hook the wire to your existing neutral bar. Make sure the neutral bar is bonded to the metal can of the panel.
    If your neutral and ground are not bonded in the barn panel you really don't have a ground that will clear a fault.
    Install the proper outlet and plug in the camper. It will work fine.
  • @ enblethan,
    Perfect, I had come to much the same conclusion. Will need to check integrity of Neutral Buss to case ensuring no continuity, will need to ensure main breaker at house functioning for disconnect before rewire, intend to disable / disconnect everything other than 1 light in shed and 1 receptacle, have 30 amp breaker free for hot power and organizing proper receptacles and have 10/3 UF wire ready to go (XS from a Well rewire). Wiring to receptacle for trailer <25ft (estimate 18.5). Will ensure stainless steel self tappers used for ground buss bar if not supplied (Paint removed at contact point, Continuity tested before live phase). Initial connect to 1st ground should be <6ft from box. Using 6 Gauge copper for ground (unbroken to 2nd). Hopefully that should cover it !

    Thank you for your reply and information Sir !
  • Buy a ground buss from your local hardware store.
    Drill and tap the box to mount it. Do not use sheet metal type screws.
    Drive the two ground rods 6 feet apart.
    Install the correct sized and type of breaker for your rig.
    Install the proper receptacle for your rig.

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