January 9, 2020

Solar Project: Grounding the System

Earth ground symbol
Electricity follows pathways. Typically, that's the wiring between the source and whatever requires electricity to operate. If there's a problem, it can jump the wiring and electrify nearby metal. This could be deadly to someone who touches it. Physically connecting the wiring to the earth gives the electricity an alternate pathway, if needed. Called grounding or earthing, this is an important safety feature.

Many solar setups tie all the components together and ground them as a unit. If we had been thinking several steps ahead we could have done that too. Because we were doing this one step at a time, Dan grounded the solar panels separately, as specified in their installation manual.

The grounding holes in the solar panels' aluminum
frames are marked with the earth ground symbol.

Lay-in lugs connect the neutral grounding wire to the panels.

This photo makes it look like the wire loop on the right is
touching itself. It's not! It's just the angle of the photograph.

The grounding wire is connected to a grounding rod.

Alternatively, the ground wire could have run
through the underground conduit (white
pipe sticking out of the ground)
 to the battery box.

At the battery bank box, the charge controller and inverter are grounded together. Each clearly shows where the ground wire attaches.

Charge controller innards. Ground wire on the right.

Inverter ground wire on the right.

The ground wires from the charge controller and inverter are connected in the battery box with a thingy called a busbar.

Busbar with two of the three ground wires attached.

The third wire above (yet to be attached) will connect the busbar to the grounding rod. The ground wire from the panel array could have been connected here too. The busbar is a conductor and will direct wayward currents from either the controller or the inverter to the ground rod.

Our second ground rod near the battery bank box.

That's a very important step accomplished!

Most of the cables are in place, but they aren't connected yet. There are a few more things to do first, and then we can put the system together.


Ed said...

Beware of copper thieves. There were countless similar setups at various small farms that dotted the countryside, mostly grounding the lightening rods on top of the buildings. But then copper prices got high and all that mysteriously disappeared from any abandoned farm. I've even seen them dig up the propane gas lines from the tank to the house as well.

Cockeyed Jo said...

I was wondering if you were going to ground your solar. LOL A DC shock is worse than an AC one. Says Jo who was once knocked across the room by DC and subsequently burned three fingers down to the bone by it. A faulty DC wire was the culprit and was living overseas at the time. It can literally stop your heart. I was lucky.

Leigh said...

Ed, thieves are always a concern, aren't they? Hopefully, that won't happen.

Jo, wow, you were lucky. That's a very hard way to learn a lesson! I'm glad it wasn't worse.

Toirdhealbheach Beucail said...

Looks Good!

Man, it is a long time since I have seen that much copper.

Leigh said...

TB, thanks! I have no idea why Dan went with copper. I know they sell them in steel, but he thinks the copper is better. So there you have it!

Powell River Books said...

As strange as it sounds, our solar system in the modified boat/shed behind the float cabin grounds to the water. - Margy

Leigh said...

Margy, interesting! Such a thing never occurred to me. But then, neither did living on water. ;) I'd be interested in what your set-up is like.