Disconnect Switch Wired 12/15/22

We got about 3 inches of rain yesterday - it rained from midnight to midnight without stopping. Crazy.

Tonight, I worked on wiring this disconnect switch. This 4/0 aluminum wire is extremely difficult to bend. I ended up cutting all the cables to length, then lifting that 90 degree elbow on top up a few inches, then working all the cables into the top of the box and into their positions. Then I used a winch strap to force the elbow back into place. For the cables coming in through the bottom, I was able to disconnect the lug plates and fit them onto the cable, then push them back onto the chassis with a hammer and bolt them back into place.

I've been wondering why the ground wire (#4 copper) is able to be so much smaller than the ground from the house (2/0). I found an answer tonight:

The ground wire never carries normal circuit current. It only carries current if there is a fault to ground. The over current protection device (breaker, fuse) will open the circuit when it detects an excessive current through the circuit. This opening of the cc't should be instantaneous for a hot to ground fault. The grounding conductor will only carry a large amount of current for a very short time, allowing for a smaller gauge grounding conductor. ~ https://www.houzz.com/discussions/2639175/why-a-smaller-ground-wire

And it always helps to have an electrician look things over, draw a pretty picture of how it should look when complete, and then not charge you $200. Thanks, Jesse - I owe you one!

Oh yes - forgot to mention - this is a commercial sized 3-phase disconnect switch, but I'm only using two of the fuses because most residential feeds are single phase. Electrician thinks it should be ok with the inspector.

Now to label all the cables, and then terminate the breaker box side of things.