Ground Wire

[Phatman]

Originally Posted by NfiniteMile

Is It Ok To Ground Wires To ANY Metal Surface Of The Bus Or Does It HAVE To Be The Chassis? I Was Thinking Of Just Drilling A Hole Through The Subfloor With A Self Tapping Screw.

You should never use a self tapping screw to ground anything. Especially 120 volts. Drill a hole, use a bolt, washer, lock washers and a nut. Self tappers can back out.

[Mozz20]

Originally Posted by Native

The wire bundle at the top are positive cables and the ones that swing lower are negative cables.. All are DC.


The green wire is the ground for the inverter/charger. The AC load panel is grounded a another location, actually to the body. In the same bundle as the green wire is a black wire about the same size as the green wire and below the green wire, this is the ground for a DC panel I added for the house side.


I ran parallel 2/0 wires for both the positive and negative between the inverter (up in the cab) as well as parallel 2/0 runs for the house batteries from the second alternator and between the house batteries in the battery box. I also ran parallel 2/0 cable between the batteries in the chassis bank as well. I figured it was easier to run two 2/0 cables than one 4/0 cable ... and the parallel 2/0 combine to act as one 5/0 cable electrically. I left the 2/0 run from the chassis alternator to the chassis battery bank as-is because it was doing what it is designed to do.


So, it looks like there is a lot more going on with that picture than it really is.


Here is what is happening on the other side of that picture (in the battery box):
Attachment 43427
That "thing" in the middle is the battery isolation relay.

Can I ask a clarifying question here? You said those top cables are the positive side. I don’t understand why you’re grounding the positive and the negative at the same point on the chassis. That seems like a really bad idea and a way to immediately short everything out. Maybe I just don’t understand this at all, i’m fine being a n00b if it clears it up. Thank you!

[Native]

Originally Posted by rydawg3000

Awesome! Thanks a lot, that really helped clear the dust for me. Now I realize I’m looking at the outside of the steps in the background!

You are welcome. The background is the forward side of the battery compartment. The battery compartment is on the driver side of the bus just behind the driver seat.

Originally Posted by rydawg3000

Also, mad kudos for making clean, even lengths in your beefy cables.

Thank you. Since I was running parallel runs, I *HAD* to make them equal lengthsor one length would be shorter thus less resistive. This can lead to more heat in the longer cable in the parallel run.

[Native]

Originally Posted by Mozz20

Can I ask a clarifying question here? You said those top cables are the positive side. I don’t understand why you’re grounding the positive and the negative at the same point on the chassis. That seems like a really bad idea and a way to immediately short everything out. Maybe I just don’t understand this at all, i’m fine being a n00b if it clears it up. Thank you!

No problem asking the question. The ground cables from above terminate at the grounding lug to the left of the picture. Also attached to that grounding lug are the negative cables for the batteries. The batteries are in the compartment behind the cables. The top (positive) cables as well as the negative cables all run into the battery compartment at the top left of the picture.

[rydawg3000]

Here’s what I ended up with:
6 AWG wire running through a 2x4 on the floor. Used heavy duty heat shrink on the portion of cable going through the floor. I also recycled a plastic sleeve from some of the original bus wiring for extra protection. Bolted to the inside of the chassis using a 3/8” bolt, washer and nylon lock not. I’m going to put a little dab of ProFlex around the hole where the cord goes through the metal floor to seal things up.

[Native]

I sure hope you used a wire brush to clean off the frame where the washer & bolt is attached. Since it is under the bus, you will want to make sure you have a rock solid connection to the frame.

[rydawg3000]

Originally Posted by Native

I sure hope you used a wire brush to clean off the frame where the washer & bolt is attached. Since it is under the bus, you will want to make sure you have a rock solid connection to the frame.

Yes I did, its just not as large as the washer, just a little larger than the end of the lug. Thinking about it, its no hassle to go back and clean off a little more to be safe. Thanks for looking out and for all the help!

On a similar note that one of you may have experience with: in my grounding research I got sucked into the truck realm and was reading about anti-static or grounding straps. Any use for this on the road when not driving? Is it a useful second layer of protection? If so, is their a strategic place to attach it?

Once again, thanks for the help Native!

[Native]

Originally Posted by rydawg3000

Yes I did, its just not as large as the washer, just a little larger than the end of the lug. Thinking about it, its no hassle to go back and clean off a little more to be safe. Thanks for looking out and for all the help!

On a similar note that one of you may have experience with: in my grounding research I got sucked into the truck realm and was reading about anti-static or grounding straps. Any use for this on the road when not driving? Is it a useful second layer of protection? If so, is their a strategic place to attach it?

Once again, thanks for the help Native!

The straps are to help control electrostatic discharge (the little sparks that you get on a dry winter day after walking on carpet, amoung other ways) when working on sesitive electronics. If you do not have one, then you can pre-ground yourself by grabbing a piece of metal attached to the frame/body of the bus. So, if you are going to have a grounding strap, then attach it to the frame/body.



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