Neutral Busbar VS. Grounding Busbar How to properly ground solar batteries and devices 24V and 12V

[sasquatch487]

Please go to my profile and read the About section for information on all of my current hardware. Thank you!

I bought an all-in-one inverter solar charge controller and utility charger for a vehicle solar system and I want to understand how to properly ground and bond all of the essential items in the system. I have downloaded a PDF and I'm reading it but it is very technical and a lot of information does not relate to my project so I thought I would start a discussion here amongst experienced people to try to get right to the point.

In creating my profile I listed all of the hardware and accessories that I've currently bought and stuff that I plan to buy. I did forget to list a 24 to 12 volt transformer to power my second fuse panel. The fridge runs on 24 volts or 12 when it's plugged into 110 it displays that it's running at 24 so I plan to run it at 24. I also think it would be smart to run my lights LED at 24 volts for best efficiency and smallest wire and any other devices I can find to run on 24 volts. My Webasto heater and Max fan are running at 12 volts and I'm sure there will be plenty of other items that I will only find in a 12 volt application so it will be nice to have both.

Where I'm at now is I have the main unit wired to the batteries and an AC input wire just to get the batteries charged from shipping. Being aware of the need for grounding I disconnected batteries and put them in storage mode for now until I can get the rest wired up. 1/0 is my biggest Cable in the system so I plan to run from my negative bus bar of the system to a separate 300 amp grounding bar then run another 1/ 0 cable to the vehicle chassis. From there I'm not quite sure how I should handle grounding and bonding things like my refrigerator the fan the heater the all-in-one solar controller etc.

I welcome all and any input and advice that I can get on the subject thanks.!

 

[12VoltInstalls]

‘Bonding’ generally implies AC voltage systems. Typically one does not ‘bond’ a vehicle DC system although your neg(-) busbar should tie a cable to the vehicle chassis at the least (I often do a homerun to the vehicle starting battery neg(-) but a good clean stout connection to the ‘body’ is good. I don’t recommend the frame as that may not be “grounded” to the battery/body with a very robust connector if at all.)

run another 1/ 0 cable to the vehicle chassis

It is fairly good practice to have that neg(-) cable be the same sized wire as your power system so it can support whatever possible fault that occurs. Good job on that.

 

[sasquatch487]

‘Bonding’ generally implies AC voltage systems. Typically one does not ‘bond’ a vehicle DC system although your neg(-) busbar should tie a cable to the vehicle chassis at the least (I often do a homerun to the vehicle starting battery neg(-) but a good clean stout connection to the ‘body’ is good. I don’t recommend the frame as that may not be “grounded” to the battery/body with a very robust connector if at all.)

It is fairly good practice to have that neg(-) cable be the same sized wire as your power system so it can support whatever possible fault that occurs. Good job on that.

Thank you for your input.

To be clear, I have 24V LIFEPO4 batteries in parallel under the bed running the low voltage house system and 2700W inverter. I don't know that I would in my case want to run all the way to the van starter battery negative as it's 12V and AGM.

At this point in order to get to chassis I would drill a hole in floor and install a bolt through with another wire to the chassis and in the case of devices run negative wires to fuse panels and any "grounding" wires ( ex. The metal cabinet of the inverter as it's mounted on wood not the metal of the vehicle) directly to the "grounding Busbar" as opposed to the negative Busbar for the system. This way I'm grounded to body/chassis for the system and components.

Would you agree that's sufficient? In the future I will also ground the solar panels.

Pics are updated. Cleaned up the wiring, connected batteries to system. Current Connected replaced the broken on/off switch with a high quality Victron ?

 

[12VoltInstalls]

Would you agree that's sufficient

As long as both DC and AC systems have a reference to the chassis at a single point the safety aspect is sufficient provided that the reference is connected with the same or larger gauge as the highest loaded cable/device used in the system for each.