The "Meg" Build

[Lt.Dan]

I feel this is the best way to describe it, but remember, I do not have the AC input wires connected to anything, as we are essentiallyessentailly "boondocking"

This is my inverter compartment, you can see the Green Wires are coming from the AC Input from the pole outside, this consists of L1, L2, Ground, and Neutral. The Yellow lines represent the AC Output from the inverters heading to the transfer switch. The L1 and L2 are kept seperate (to power each have of the breaker panel later), whereas the Grounds are connected together, and the neutrals are connected together.



This is the actual brand/model transfer switch I have. This transfer switch has a Generator input priority, (which is where the inverters are connected to) This represents the red line coming from the Grid, and also splitting off to meet the green wire in the previous picture to supply AC input to the inverters. The yellow line is a continuation of the AC Output from the inverters. The blue lines represents the wiring going out to the Breaker Panel/ Distribution panel, the blue wiring is still factory, as well as everything in the breaker panel.


Let me know if this helps, or if more information is necessary.

 

[12VoltInstalls]

I’m following this! Geesh, 101V with a probe in dirt is pretty likely 120V in reality.

Take the safety ground port of an exterior outlet and poke the metal of the RV and see what it says for kicks. If you’re not earth grounded at the shorepower socket then one can assume you have a circuit in place through the tongue jack.

But if that is letting you get zapped from the body of the RV to the earth, why isn’t a fuse or breaker blowing?! I can’t see this happening but you’re making me want to play some games with a vom myself.

My bare copper gains its earth from the Giandel inverter and I believe the RV breaker box has a bare to the frame. Plus my 12V battery neg(-) is frame-tied.

In one spot it sounds like you’re unplugged from the shorepower mast, in another it seems like you are? I’d unplug to troubleshoot.
(That’s one cool thing about small 12V systems like mine: I simply have a cord wired to a duplex GFCI and the male plug stuck into an inverter outlet with the RV 30A cord plugged into the GFCI using a 20A adapter. No funky laurel/hardy tesla/ohms tricks can happen)

 

[Lt.Dan]

View attachment 69830

To answer your questions from left to right, top to bottom:

Connections is shore power all correct? I would assume so, it has not been modified, but also is not connected, so I believe this is irrelevant.

Could any of the neutral and hot lines be swapped? This has been confirmed to be correct, all the wiring colors coordinate correctly and ensure they are not mixed up.

Is there a connection from inverter case to chassis? Not a physical wiring connection, but the inverters are mounted to bare aluminum, which is then screwed to the chassis in several places. I'm assuming it is making connection through there?

Is there a connection from AC ground to chassis? Not that I am aware of, unless the manufacture did.

Is there a connection between neutral and ground in the box? It is NOT.

 

[FilterGuy]

Connections is shore power all correct? I would assume so, it has not been modified, but also is not connected, so I believe this is irrelevant.

You are getting the shock when not connected to shore power? Is it completely unplugged?

 

[FilterGuy]

The Inverters have a transfer switch already built in. What is the purpose of the automatic transfer switch?

 

[Lt.Dan]

You are getting the shock when not connected to shore power? Is it completely unplugged?

Completely. Nothing plugged in.

The Inverters have a transfer switch already built in. What is the purpose of the automatic transfer switch?

I figured i could use the automatic transfer switch is incase the inverters die or fault out, and I am plugged into the grid, then the rig will still get powered from the grid. This doesn't leave me stranded if the inverters fail (which has happened)

 

[FilterGuy]

Completely. Nothing plugged in.

hmmmm that is baffeling. I am struggling to understand the circuit path that was shocking you.

I assume you have a tung jack and or leveling jacks deployed....???

 

[Lt.Dan]

hmmmm that is baffeling. I am struggling to understand the circuit path that was shocking you.

I assume you have a tung jack and or leveling jacks deployed....???

Leveling jacks, but they are sitting on plastic blocks. I understand the tires have some carbon in them, but not much??

 

[FilterGuy]

Leveling jacks, but they are sitting on plastic blocks. I understand the tires have some carbon in them, but not much??

Wow... that is strange. To get a shock, there has to be a circuit. I have never heard of tires that would conduct... but who knows.
Is there anything else that could be connecting the trailer to earth?

Is the trailer parked under power lines?

Try pounding something metal into the ground (since you got the 'tingle' in just the dust, it does not have to be deep). Then hook a wire between the ground and the aluminum that gave the shock. Put a clamp-on ammeter and see what current there is.

 

[Sanwizard]

Well I just had a pretty wild experience that may or may not be dangerous. While working on the trailer, I happened to have my right hand in the dirt amd my left hand on bare aluminum on the rv. I felt a slight tingling sensation and realized the trailer was shocking me! After getting out my multimeter I found this:

View attachment 69818

A full 101v!

I know I unplugged from the 50 amp pedestal we parked next to, and im sure while connected to the pedestal, it also connected us to the grounding rod that the pedestal is connected to. But is this something to worry about? Or perhaps something i can prevent?

Similar problem that DanF had on his LV6548's and grounding. He fixed it, but I dont remember how. Perhaps ask on his Youtube channel.

 

[Lt.Dan]

Wow... that is strange. To get a shock, there has to be a circuit. I have never heard of tires that would conduct... but who knows.
Is there anything else that could be connecting the trailer to earth?

Is the trailer parked under power lines?

Try pounding something metal into the ground (since you got the 'tingle' in just the dust, it does not have to be deep). Then hook a wire between the ground and the aluminum that gave the shock. Put a clamp-on ammeter and see what current there is.

The only thing I can think of is there is a 200ft run of 10ga PV wire going to the shipping container. Im guessing the trailer could make connection through 200ft of wire, into the PV, through the container, and into the same dirt, 200ft away.

Other than that and my water/sewer connections, nothing connects it to the ground, and no power lines overhead

 

[Lt.Dan]

Similar problem that DanF had on his LV6548's and grounding. He fixed it, but I dont remember how. Perhaps ask on his Youtube channel.

@DanF, is this something you can answer here?

 

[Lt.Dan]

I just drove a pretty big screw driver into the ground, and with a wire connecting the two, there shows no amperage if set to AC or DC, and voltage between the two only shows 88V, but DAMN the shock is much worse if I touch the aluminum on the trailer and the screwdriver!!!

EDIT: Also, with the wire attached to the trailer and the screwdriver, there is no shock when my hands touch the ground and the aluminum itself

 

[time2roll]

Since you have a voltage reading..... start disconnecting something. This is a process of elimination.
Divide and conquer.

 

[FilterGuy]

The only thing I can think of is there is a 200ft run of 10ga PV wire going to the shipping container. Im guessing the trailer could make connection through 200ft of wire, into the PV, through the container, and into the same dirt, 200ft away.

I have no reason to think the PV lines have anything to do with it, but try throwing the PV disconnect to off and see if the voltage is still there.

 

[Sanwizard]

I just drove a pretty big screw driver into the ground, and with a wire connecting the two, there shows no amperage if set to AC or DC, and voltage between the two only shows 88V, but DAMN the shock is much worse if I touch the aluminum on the trailer and the screwdriver!!!

EDIT: Also, with the wire attached to the trailer and the screwdriver, there is no shock when my hands touch the ground and the aluminum itself

I think your Nuetral and ground may be connected inside the inverters. Check for voltage on inverter ground please.

 

[FilterGuy]

DAMN the shock is much worse if I touch the aluminum on the trailer and the screwdriver!!!

That convinces me that it is a dangerous issue that needs to be corrected. With the screwdriver, the connection to the earth is better so the shock current is higher.

there shows no amperage if set to AC or DC,

It may be only milliamps, but if your are feeling the shock, there is current.

EDIT: Also, with the wire attached to the trailer and the screwdriver, there is no shock when my hands touch the ground and the aluminum itself

That makes sense. The wire is a very low impedance path so it is taking the vast majority of the current. You are much higher impedance so the current through you will be very small.

 

[FilterGuy]

I think your Nuetral and ground may be connected inside the inverters. Check for voltage on inverter ground please.

I would be concerned if they are not connected! (A neutral-Ground bond is needed for the breakers to properly clear faults.

As is typical with MPP, the manual does not explain its ground scheme. However, I suspect there is no N-G bond.

This is a problem with using inverters that are targeted for home/stationary use in an RV. In an RV there needs to be an NG bond when on the inverter and NO N-G bond while on shore power.

However, I am not sure how the lack of an N-G bond would create the problem the OP is describing.


I agree with @time2roll. Start disconnecting things one at a time and see when the problem goes away.

Here are some easy things to try:

Turn off the PV
Turn off the Inverters
Turn off the main breaker in the breaker box.

 

[12VoltInstalls]

struggling to understand the circuit path that was shocking you.

neutral-Ground bond is needed for the breakers to properly clear faults.

A poorly connecting chafed wire?

Although I’d be entirely in awe, entertained and fascinated if the 88V disappears with the PV neg(-) and pos(+) disconnected…

Do you have a waterline connection anywhere? Disco lights outside plugged into ye olde campair? I wanna drive over and figure it out.
I found a Bad Thing in a trailer once when I pulled a piece of metal trim off and it sparked. I discovered a ~66V AC drywall screw in a house that a couple rooms went dim when the cellar light was turned on. Fun stuff!

 

[FilterGuy]

Although I’d be entirely in awe, entertained and fascinated if the 88V disappears with the PV neg(-) and pos(+) disconnected…

I agree but 1) the OP says the run 200 ft to another structure and 2) with the slick disconnect shown in the picture, it is very easy to try.

To get the shock, there must be some kind of circuit. If the only connection between the RV and ground was through the OP, there might be a static shock, but there would be no sustained shock. That tells me there is something else connected between the trailer and earth ground.

Do you have a waterline connection anywhere?

Other than that and my water/sewer connections, nothing connects it to the ground,

I reckon there could be some kind of path through the waterline or maybe even the sewer line. If it is easy to disconnect, that would be good to try as well. (I am not sure what the next step would be if that stopped the shock)

Disco lights outside plugged into ye olde campair?

Something like that could explain it.