How should I ground my electrical/ solar system

[Mr. Goodkat]

I've done some research and I'm still confused as to wether I should have a chassis ground or have my AC and DC both grounded back to my battery bank only.

*I don't have my house system connected to my alternator and I don't plan to anytime soon. I have a Furrion 30 amp shore power inlet and plan to use our Honda eu2200i generator when necessary.

I have a Midnite Solar disconnect box with a 250 amp disconnect to manage the input and output power from the battery bank and charge controller. So far everything is grounded to the bus bar in the box except for the ground for the inverter/charger that I still have to make a ground wire for. The inverter charger will also be grounded to the bus bar.

Obviously I don't want to create a hot skin situation.

My question is basically how should I ground my system?

Should I run a ground wire from the busbar in the box to the chassis?

Do I skip the chassis ground all together? Or do I run a 4/0 ground cable from the inverter side of the shunt into the box and to the ground stud in the box which should then ground the busbar to the battery bank only?

The shunt wouldn't mount in the box properly so I decided to mount it outside the box. Right now I have a 6 gauge ground wire running from the inverter side of the shunt directly to the ground busbar but I suspect that might not be the correct thing to do or that the 6 gauge cable should be replaced with a 4/0 cable.

Hopefully my pictures give you a good idea of what I have going on. *I just noticed I have the input ground on my DC-DC converter in the wrong position so I'll be challenging that*

[john61ct]

Your AC side is a COMPLETELY different topic.

Get a pro to sign off on your plans for that.

What follows is wrt DC only.

There is no "true Earth ground" in a rubber-wheeled vehicle.

The Common Reference at all points in your DC circuits should be the same, and that can be accomplished by tying your Negative buss points to the engine block and chassis at as many locations as you like.

But do not rely on those for your Negative Return paths, those should be via the same gauge wire back to source

for anything high-current, expensive or important.

Isolation devices, switches, circuit protection etc should be on the Positive paths, close to sources.

[Rwnielsen]

Just a quick note, phase your AC wiring. Neutral is white or neutral grey and ground is either green or bare copper. This will make it easier and safer down the road especially if someone else is troubleshooting it. Phasing tape is available at Home Depot and the like...

[cntryby]

Most better quality inverters have a RCD (residual current device) and a ground lug on the inverter chassis. This can be used to tie to a ground bus for DC.



Gen-sets are the same, I believe the super quite "Honda EU" line is floating neutral.

Shore power should provide ground through the plug.


You can check with the manufacture, but I would probably isolate the different circuits and their grounds. This means the inverter and gen don't ground to the bus chassis. This means switch gear needs to be sourced that maintains isolation... including the bus batteries.

What are the rules on links I have a couple of articles that are relevant.

[cntryby]

Without seeing your whole system, it's really hard to say, but it looks as if your grounds are all tied to you metal boxes. Without a true earth or grounds being tied to an RCD if you have an appliance / equipment failure your metal box could become HOT. If wood is your only insulator (wood is a conductor) it could start a fire as the current is trying to flow to the bus chassis if it is still tied to the neg battery post.

You can not wire a bus like a house, at least not safely.

[Mr. Goodkat]

Originally Posted by Rwnielsen

Just a quick note, phase your AC wiring. Neutral is white or neutral grey and ground is either green or bare copper. This will make it easier and safer down the road especially if someone else is troubleshooting it. Phasing tape is available at Home Depot and the like...

I have 6/3 wire that will be going from the AC OUT in the inverter to the 70 amp box. The ground will obviously go to the ground bus bar but if I'm correct the neutral goes to the lug/neutral bar on the right of the breakers.

For my AC circuits I'm making them 20 amps and using 12/3 boat wire. The same goes for my air conditioner.

[Mr. Goodkat]

Originally Posted by cntryby

Most better quality inverters have a RCD (residual current device) and a ground lug on the inverter chassis. This can be used to tie to a ground bus for DC.



Gen-sets are the same, I believe the super quite "Honda EU" line is floating neutral.

Shore power should provide ground through the plug.


You can check with the manufacture, but I would probably isolate the different circuits and their grounds. This means the inverter and gen don't ground to the bus chassis. This means switch gear needs to be sourced that maintains isolation... including the bus batteries.

What are the rules on links I have a couple of articles that are relevant.

My inverter/charger does have its own ground terminal on the bottom right corner of it's frame. My MPPT charge controller and DC-DC converter both also have their own ground separate from their input and output leads.

This is a diagram that I've been studying while anticipating my electrical portion. It's not exactly the same as mine but a couple of components are the same.

I might call this guy I saw on Tiny Home Tours. He has I nice bus conversion with one of the biggest and most sorted electrical systems I've seen. He obviously knows what he's doing and he said he's willing to help people. Their bus is called the Broccoli Bus.

[Mr. Goodkat]

Originally Posted by cntryby

Without seeing your whole system, it's really hard to say, but it looks as if your grounds are all tied to you metal boxes. Without a true earth or grounds being tied to an RCD if you have an appliance / equipment failure your metal box could become HOT. If wood is your only insulator (wood is a conductor) it could start a fire as the current is trying to flow to the bus chassis if it is still tied to the neg battery post.

You can not wire a bus like a house, at least not safely.

Yeah it's turning out to be trickier than I thought, I know I can do it and get it done. I just thought it would be easier to get the answers I need to get it done with all of the conversions out there or all the manufactured RVs out there setup for solar.

Part of the process and the fun of a skoolie!