Question about grounding.

[HaldorEE]

I have been thinking about chassis grounding my van based RV system. You can see the electrical drawings here.

24V Van System Drawing. Get your overripe tomatoes ready!

After months of pontificating, I have finally pulled together the electrical design for my RV conversion. Let me know what you think. This is my first version and I would much rather fix as many problems at the pixels on a screen stage as I can.

diysolarforum.com

I plan on having alternator, solar and shore power. The inverter (Victron Multiplus) will take care of AC neutral/gounding. I am connecting to the vans electrical system which does tie the battery negative to the van chassis.

The alternator DC-DC charge controller (Victron Orion TR Smart) come in an isolated or unisolated version. Is there any real reason to keep my house battery negative rail isolated from the van chassis ground?

Are there any upsides or dowsides to either scheme? The isolated DC-DC controller only cots $40 more and I can always bond the two grounds together if I decide to do so later.

Opinions? Suggestions for further research?

 

[HaldorEE]

Should I keep the AC ground isolated from the Van chassis ground? I am planning on using metal armored MC cable for my AC wiring. That would need to change if I need to keep AC ground and van chassis ground isolated.

 

[Zil]

If you ever plug into a pedestal for AC you definitely must have your chassis bonded to the green earth ground wire. I don't see where the chassis needs be separated from the AC ground. You do need the AC neutral isolated from the chassis, same as AC hot. My inverter has a case lug that is connected to my common negative chassis. So the AC ground is to the chassis. I don't know your B to B devices. But I prefer my chassis negative all bonded together.

 

[HaldorEE]

I kinda answered my own question. The only reason to not get the galvanically isolated DC-DC charger would be to save $40. That is not a good enough reason for me.

I have updated my system drawing in the linked thread to reflect that.

That way I can bond AC ground to chassis ground without the slightest concern.

 

[HaldorEE]

If I ever decide to bond my house system negative to chassis ground, I can do that with a jumper wire.

 

[HaldorEE]

The MidNite Solar device goes on the AC connection. I thought you were referring to something between the solar panels and the SCC. My bad.

Amazon.com: MidNite Solar Surge Protection Device MNSPD-300-AC: Electronics

Buy MidNite Solar Surge Protection Device MNSPD-300-AC: Surge Protectors - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Looks like this is required per UL 1449. Is this only for systems that backfeed the grid?

Looks useful to protect against surges when connected to shore power and in that mode grounding is provided by the shore power connector. Not a bad idea.

Posted to wrong thread.