Please give input on my electrical system design

[highdesertranger]

your controller should have a battery positive, and a battery negative. you have the battery positive marked but don't have a battery negative. I was thinking the terminal you have marked as ground was battery negative. if it is battery negative and you hooked it straight to your battery you would be talking the solar out of the loop and the meter would not read it. again I was told only one ground wire on the battery and this wire goes to the shunt all other grounds hook on the other side of the shunt. highdesertranger

 

[B and C]

your controller should have a battery positive,  and a battery negative.  you have the battery positive marked but don't have a battery negative.  I was thinking the terminal you have marked as ground was battery negative.  if it is battery negative and you hooked it straight to your battery you would be talking the solar out of the loop and the meter would not read it.  again I was told only one ground wire on the battery and this wire goes to the shunt all other grounds hook on the other side of the shunt.  highdesertranger

His battery negative from the controller is connected to the bus that is chassis ground.  This way the solar output goes through the shunt to the battery and the shunt sees it so it can be measured.  The drawing shows those two common grounds a ways apart but are actually right next to each other on the actual controller that he linked to.  His labeling shows common negative.

His drawing is correct.  There is the negative from the solar panel to the controller and a negative from the shunt to the controller.  Those negative are common on the controller.

 

[FALCON]

like this?

 

[Optimistic Paranoid]

Get rid of the green wires/connections all together.  Those connections are for earth ground, not battery ground and are not needed in a mobile environment.

Really nice diagram

I am coming to this discussion a little late, but I think I am going to dispute this comment.

The instruction manuals for both my Samlex and my Morningstar inverter specifically call for a separate ground wire from the ac side of the inverter to the chassis.  If his inverter has a terminal for ac safety ground and the manual calls for it to be used, then he should certainly do that.

I didn't see anything on his diagram about shore power or a converter.  My rig will have both, and I will be certainly grounding the vehicle chassis to the 3rd wire on the shore power cable for safety.

Regards
John

 

[B and C]

Yes, except you don't need a fuse or breaker on the negative side.  All fuses go on the hot / positive side.  Everything metal in a van is a ground and you don't have any control over those.  All positive / hot wires are seeking this ground and need to be fused.  A big cable from either the ground side of your shunt or the buss bar is fine.  If you are going to use the buss bar as your frame ground, you need a large wire from the shunt to the buss bar too.  Four gauge minimum.  Ground the negative cable to the frame and the body.  You want a good ground everywhere.  This can help reinforce the factory ground bonding of the frame, engine and body otherwise you will be relying on the factory bonding under the hood.

 

[Optimistic Paranoid]

See this old thread:

https://vanlivingforum.com/Thread-The-Wrong-Fuse?highlight=disaster+fuse

. . . for a discussion as to why you MIGHT want to fuse the negative chassis ground to battery coonection.

Regards
John

 

[speedhighway46]

Be sure to keep the ac neutrals and grounds separate, not connected as they are in normal house wiring. This is known as floating neutrals and is required in RV wiring.

 

[B and C]

After going and reading the linked to thread, it seems that the inverter is what is causing all the angst.  Since it can short out and back feed 110v to the 12v system, I would just fuse the ground for it by itself.  Combining the ground from the inverter to the 12v ground  before the fuse doesn't prevent a problem as they're still connected before the fuse.

I have worked on DC systems almost my entire life first starting on cars drag racing.  I then went on to build a couple of vans that we traveled in extensively.  I have installed big sound systems in cars too.  I now have a RV that I have done a lot of electrical work on.  I have a career as a telephone technician since 1972 (telephones work on 48-52 VDC).

 

[ccbreder]

Electrons move from the source back to the source. Like; terminal battery-one back to terminal battery-one. Or; 120V hot back and forward to 120V neutral. You would have to show me the schematic allowing 120V inverter hot, to feed back to 12V negative, that does not blow the 12 volt positive fuse. A fuse is not needed in a safety ground, inverter or not.

 

[B and C]

I am clueless on the inverter stuff.  I have a 200w model that is not grounded at all (other than battery negative).  It is hardwired into the battery bank with a fuse on the positive though.

 

[speedhighway46]

Oopslala: this is the thread.

 

[BradKW]

In the last diagram, there are two positive wires from the battery, one to inverter and one to positive bus bar. Is there any reason that this can't be done with just one wire instead, say the 2awg to buis bar and then more 2 awg from bar to inverter?

If there was a charger in this system, would the bus bar be appropriate place to connect?

And with respect to grounds, I understand that when we drive a spike 6 feet into the earth for a house ground, that the current can now go into the ground. That makes sense to me. But in a vehicle that is insulated from the earth on 4 rubber tires, what does grounding to the frame actually do?

 

[Mobilesport]

In the last diagram, there are two positive wires from the battery, one to inverter and one to positive bus bar. Is there any reason that this can't be done with just one wire instead, say the 2awg to buis bar and then more 2 awg from bar to inverter?

If there was a charger in this system, would the bus bar be appropriate place to connect?

And with respect to grounds, I understand that when we drive a spike 6 feet into the earth for a house ground, that the current can now go into the ground. That makes sense to me. But in a vehicle that is insulated from the earth on 4 rubber tires, what does grounding to the frame actually do?

If the invertor is supplying your needs while connected to the bus bar its fine connected there.
I would wire the charger directly to the battery for less voltage drops and less connections.
The frame just acts like a huge busbar , plus it simplifys your wiring by not having to run long ground wires.
Ask ,,,what is a floating ground??????    
I still hav'nt figured that out yet.

 

[Mobilesport]

He's got a 100 amp fuse inbetween the neg bus and chassis ground ???
He dont need that does he???
And he also has a 50 amp fuse by the controller battery + , should'nt that fuse be on the other end close to the house battery pos terminal?

 

[Mobilesport]

He's got a 100 amp fuse inbetween the neg bus and chassis ground ???
He dont need that does he???
And he also has a 50 amp fuse by the controller battery + , should'nt that fuse be on the other end close to the house battery pos terminal?

 

[Mobilesport]

Do you mean absolutely no grounding to the frame at all, like this?

Or, still ground the battery to the frame, like this?

All of them ground wires that you have on the right side of the shunt need to be moved to the left side of the shunt , there should only be one wire that goes from the battery neg to the right side of the shunt , nothing else.

 

[FALCON]

This was the last version of my wiring diagram:

Full size:

My actual wiring was either the same as this diagram, or quite close to it. I did it about 8 months ago now, so I can't remember for sure. The charge controller remote temperature sense wires are ok and/or recommended in the Morningstar manual to go to the negative battery terminal. These are not ground wires, they're just wires for a thermocouple.

 

[FALCON]

In the last diagram, there are two positive wires from the battery, one to inverter and one to positive bus bar. Is there any reason that this can't be done with just one wire instead, say the 2awg to buis bar and then more 2 awg from bar to inverter?

I'm no expert, but yes, I think the inverter could be wired from the bus bar. I don't recall for sure why I did it separately. I just checked and all my versions of the diagram, from the very first one, had the inverter wired separately from the battery. (So it may only have been that I started it out that way without all that much specific reasoning, and then just never thought about it much, or never had enough reason to change it)

If there was a charger in this system, would the bus bar be appropriate place to connect?

I'm not exactly sure what you're asking here. I do have a charge controller as shown on the diagram, connected to the bus bar.

And with respect to grounds, I understand that when we drive a spike 6 feet into the earth for a house ground, that the current can now go into the ground. That makes sense to me. But in a vehicle that is insulated from the earth on 4 rubber tires, what does grounding to the frame actually do?

I'm not sure. I suppose the van frame is better than nothing at all, but I'm no expert.

 

[BradKW]

I'm not exactly sure what you're asking here. I do have a charge controller as shown on the diagram, connected to the bus bar.

Thanks... I meant additional charging via a 120v converter from shore power, or an alternator...

oh, what are the powerpoles for on either side of fridge?

 

[FALCON]

Thanks... I meant additional charging via a 120v converter from shore power, or an alternator...

oh, what are the powerpoles for on either side of fridge?

They are Anderson Powerpoles. They work well for connecting (and disconnecting) wires together. The fridge came with a power supply wire. One end of that wire plugs into the fridge (with some kind of specific plug end), the other end has a male 12v cigarette lighter end. The Powerpoles allowed me to run my own wire from the battery to the fridge, and connect that wire to the fridge power supply cable.