Grounding Question

[Capebuild]

Should I be running a wire from the negative terminal of my lithium house battery to the steel chassis frame to act as a ground?
If so...... I'm using a shunt connected to Victron battery monitor. Does this need to be considered if running a ground wire from battery.....
I guess what I'm asking ... should the ground wire to frame be connected to shunt or to battery neg terminal?

Thanks

John

[Benno]

The shunt needs to be connected to battery neg terminal then from shunt to either chassis or busbar. so all loads and charging runs through it.

Sent from my SM-G970F using Tapatalk

[TimC]

Im really interested in the answers to John's question. I don't understand why someone would ground to the chassis on a teardrop.

I get it on a boat trailer for brake/turn/tail lights. Saves the manufacturers copper running one less wire to all the lights. But most of the lights are mounted on or near a metal frame.

[Tom&Shelly]

Im really interested in the answers to John's question. I don't understand why someone would ground to the chassis on a teardrop.

I get it on a boat trailer for brake/turn/tail lights. Saves the manufacturers copper running one less wire to all the lights. But most of the lights are mounted on or near a metal frame.

I'm with you Tim: We didn't ground either our 12 house battery system or our road safety light system to the trailer frame. For both of those, we ran separate negative wires back to the battery. I believe the systems are more reliable that way.

For 120 vac (shore power), it's a safety issue and the frame should be grounded to that system.

John, if you are using the frame as a return on your 12 volt battery system, the shunt should go before the frame ground, as was state above (by Benno). The shunt is measuring the electrons going into and out of the battery to keep track of its charge, and so it needs to "see" everything including any lights, etc. using the frame as a return. (Hope that makes sense.)

Tom

[MickinOz]

It is expressly prohibited to use a chassis as a ground here in Oz.
Thou shalt not rely on a chassis ground for the return leg of any circuit......
A particularly bad thing on a boat trailer that is being dipped in water.

[Capebuild]

Thanks for the help and replies.

I'm not using the chassis for any my components running off the house battery. (I do have a ground to chassis as part of the lights coming off the TV that are powered by the TV's battery, but that system is a 7 pin connection which also includes a ground).

I was just asking about the house battery system (cabin lights, fridge, fan, etc). I've posted a picture of what my elex set up will look like.... so you can see what I'm referring to in my original question. Wondering whether I need a ground as shown in the image??

Thanks!

John

[saltydawg]

The official electrician in me says to run a ground wire to the frame, but dont use the frame as a conductor. The reason for the frame being grounded, is in case anything ever shorts to ground it will blow the fuse. Figure the only thing that the wire can really short to is the frame, wood wont short. Since your not using the frame as a conductor, just a safety thing connect it to the neg any where, as it should never carry power anyway the shunt wont care. But its not like 12 volts is very dangerous.

Same reason with a 110 volt system you should run the 110 ground to the frame, better to have it short and trip than to energize the frame. Now this does not matter much on teardrops with very very basic 110 volt systems, this is more of an rv thing.

[twisted lines]

If using the tow vehicle alternator / battery to charge the camper the ground must be connected to each battery so if you have problems doing so perhaps the tow ball is not enough

I started with the intent to not Ground my frame because "Dissimilar Metals"
Now 1 marker & 1 blinker in a corner of my city bumper will use the frame ground, And I Know its grounded very well!
If I want to charge the battery while connected to the T/V; One switch will do it.