Trailer neutral/ground bonding

[boondox]

Hey All,

I just want a double check here. As a self edgimicated guy sometimes I miss things.

I have always understood that the ground and neutral should be bonded in only one place. I just sold my teardrop trailer to some friends and as soon as they plugged it into their outdoor GFI protected outlet it popped. I came over and took a look and found that the trailer's breaker box has all of the neutral and ground wires connected on the neutral bus and a clip from the neutral bus to the ground. Definitely done at the factory (the trailer was made by Hunter). I had never plugged it into a GFI outlet and had never discovered this.

Is there a reason for this? Is there some safety issue I am unaware of? If one was only powering the trailer with a generator that didn't have the ground and neutral bonded it would be good, but this trailer will only be plugged into shore power.

Assuming that I should separate the ground and neutral I will get a ground bus, switch all the grounds to that and remove the bonding clip. I also noticed that the skin of the trailer is not connected to ground, it seems like that would be a good idea too.

Thanks!

 

[Zil]

The only connection to mother earth ground should be the green wire from all the outlets and devices back to the main power panel from the grid. The common white wire should not be cross connected to the green except at the original power supplier at the main panel. The chassis and metal skin of the vehicle should be connected to the green earth ground. It is very important that this green mother earth ground is sound from chassis to the main panel from the grid.

 

[boondox]

That is what I have always understood. It is strange in this case as this is how the manufacturer did it and Hunter is a pretty big, well known outfit.

 

[Zil]

RV builders are overwhelmed by sales and have hired many new employees.

 

[boondox]

Well, this trailer is 18 years old or so. Doing some reading and I guess the best course is to separate the neutral and grounds. Still wonder why they did it and if they know better than I.

 

[MrNatural22]

️️️ As a beginner when I wired my cargo conversion for shore connection I read the RV box is a sub panel and to never
bond neutral and ground on a RV sub panel.
Touching your door handle or trailer skin when barefooted will get your attention quickly if you do it wrong. ️️️?

 

[Mike Jordan]

NEC says grounding and neutral wires are connected to the same buss bar, in the main panel. (where the main breaker is) They are only separated in a sub panel. (a panel down stream from the main breaker panel) Your TT should only have one 120v panel, that would make it the main panel. If the main breaker is there, that definitely makes it the main panel. So without seeing it, that sounds like it is wired correctly

The issue is probably the GFCI outlet at the house. They are not designed for the scenario. It may be, getting overloaded by the batt charger... or something. If the GFCI is older, replacing it "may" help. Or make sure there is zero load when you plug it in. Then try adding loads. But to plug the RV in, you may need a non-GFCI outlet

 

[RCinFLA]

GFI's require all the current going out the hot line return via the neutral line. If you tie ground and neutral together at trailer some of the return current goes back on neutral and some on ground wire. Pop goes the shore GFI.

 

[MrNatural22]

An RV panel is downstream from the main panel that is the source to which the RV plugs into for shore power (main breaker) That makes the RV panel a sub panel, and neutral and ground are separate.

 

[carbon60]

An RV panel is downstream from the main panel that is the source to which the RV plugs into for shore power (main breaker) That makes the RV panel a sub panel, and neutral and ground are separate.

Just to elaborate a bit on a slightly old thread: the RV panel is a sub-panel until unplugged from the grid and on its inverter, at which point it becomes the "main" panel. This is why proper inverters with built-in transfer switches have a relay that bonds neutral and ground when "off-grid".

 

[boondox]

Yep. The real question was why the manufacturer chose to bond the ground and neutral and was there a particular reason. I went ahead and separated the two, adding a ground bar.