I've spent much of this last week prepping the new inverter stack for the solar. Last December I got the thing home. It's HUGE. It took 2 strong folks to drag the thing into the shed. This presented a problem for installation. I solved that by removing the two 80+ pound inverters from the panel. I carefully mapped out what went where and have a process map for reinstall after the panel is mounted. Then I finished prepping the panel by selecting where things would come in and doing at least the preliminary hole drilling/knockout set process and putting in fittings where I could. Following that I installed the Automatic Generator Start (AGS) module. This means finding a place within the panel raceway that will accept something that size without getting in the way of the cabling that'll be put in there and allow me to get to it well enough to still wire it in after setting the panel.
After that I started on the combiner box prep. With the new higher voltage panel strings I"ll be running I had to get a 12 place combiner box that ends up accepting 6 double breakers. Equipment manufacturers have discovered that the original solar DC breakers tend to explode at the higher voltages even if they're rated for that voltage and the solution is this double breaker thingy. It's weird when one is used to the old way. The wiring both enters and exits on the top side of the breakers and there's this giant buss bar you have to assemble. That and I needed a larger knock out than the pre-made knockouts allowed so I had to remove one neutral bar (only needed one, not two) so that I could drill a hole and use my knockout set to make the right size hole on the right side (correct side, it was actually the left side) of the box.
Now comes the battery box DC disconnect. Yes, the double stack inverter setup from Magnum Energy has a set of disconnects in the panel. 2015 National Electrical Code requires a rapid shut down system be installed on roof top mounted solar for the purpose of safety for fire first responders. That and I like being able to completely kill out the feed to the panel if I need to get in there and work on stuff. This one was the easiest one to set up . The knock outs are already the right size. I did have to swap out the Midnight 250 amp breaker for one that will accept the Rapid Shutdown System (RSS) breaker. It looks like I can also wire in some din mounted breakers for various low voltage stuff later on if I like. The breaker has a spot for a ground so I drilled a hole for that and it also has a ready stud for the neutral from the battery box. No, I'm not running double 4/0's into the breaker, they'll run directly from the battery box to the inverter stack. I will run a nice little #4 or #6 from the battery box to the stud for later. It's always good to do it now, not later. Later you have to back up 3 freakin miles to undo stuff so that you can re-do what you need to.
Then I had to map out how to run the piping. This is no small thing. Into the inverter stack come two 2" battery feed pipes carrying two 4/0 wires each. Then there is an 1 1/2" carrying the house power feed. Then an 1 1/4 from the combiner box, another 1 1/4 for the generator power feed, a 3/4" feed for the generator control wiring (can't run control wiring and power in the same pipe (NEC again). Then you have your ground wire (#4 copper) and various lan cables.
I have a map for that. :D
Hopefully this weekend we'll be able to throw the dang thing up there. Crys will help as we can now handle the weight of the stripped panel together. I sure hope I've pre-measured everything right.
When that's done I can start getting the rails up for the new solar. We're going from 2 KW in panels (9) to 6 KW in panels (24). It'll cover the roof and should take care of things nicely for us. The old system will go into a building I've already set in place to supply Crystal's fiber studio when we get that built.
I keep thinking if I was just retired I would have time to do all this stuff much quicker.
On another note, Crys gets home today after being gone for a week fetching our niece, Autum. We're looking quite forward to our summer.