Grounding - common or separate?

[MadCompSci]

Electrical question:

I have a 24VDC solar array and inverter for 120VAC and a converter for solar-powered 12VDC. I also have the 12VDC bus power.

Should I tie the negative of all these systems together or keep them separate?

[rossvtaylor]

Your 12VDC ground (negative) should be bonded to the chassis. The ground (not the neutral) of your 120VAC should also be bonded to the chassis. Your solar panel wires (the + and -) will run directly to the charge controller, through a breaker or fuse (preference given to a breaker with a disconnect function)...and those wires won't normally be bonded to the chassis.

[Booyah45828]

I don't think I would. Your chassis is already 12vdc-, I don't think I'd want to risk any issues pushing power where it doesn't belong by connecting your 24vdc- to the chassis as well.

Have an open on the negative side of the equation and with it grounded to the chassis the power will attempt to find another route, which might not be up to the task. I don't know how many amps your solar array is, but I feel that a lot of the grounding cables and straps aren't designed for high amperage.

[HamSkoolie]

Originally Posted by rossvtaylor

Your 12VDC ground (negative) should be bonded to the chassis. The ground (not the neutral) of your 120VAC should also be bonded to the chassis. Your solar panel wires (the + and -) will run directly to the charge controller, through a breaker or fuse (preference given to a breaker with a disconnect function)...and those wires won't normally be bonded to the chassis.

Well I tried to "thank" you Ross but apparently I've thanked you too many times and have to "spread some thanks around" before I can thank you again.
Grrrrrrrrrrrr