I'm trying to plan my system. I'm trying to design something with nice components and do not wish to cut any corners. I'm finding a lot of examples but often the explanations are lacking. I have a few questions about the diagram for a similar system that I'm looking at (image linked below). First, they put a battery cutoff switch between their battery and inverter. I'm not opposed to doing this but I'm trying to understand what this adds. Isn't the power switch on the inverter a battery cutoff switch? Wouldn't an additional switch just be redundant? They also put a switch between the charge controller and the battery. What could this be for? To be able to remove the battery without current from the charge controller terminals? This doesn't make sense to me because you are not supposed to have most controllers wired to PV panels without a battery, therefore there should be no charge when disconnecting anyway because the PV panels should be disconnected first. Will you please explain these switches to me!?! I'm not opposed to installing them but I don't want to put in unnecessary parts that could increase resistance or add unimportant additional points of failure. [url]https://gnomadhome.com/wp-content/uploads/2017/02/system-diagram-correct.png[/url]

This is probably a topic that's been brought up over and over again... I've dug trenches and buried conduit for outbuildings in the past -- installed subpanels to both my previous houses' workshops / sheds. However, I recently got married and we moved into a little larger place that has a pretty built out backyard, complete with a pool and very large pool deck. The scenario I have is -- there's a shed that I'd like to use as a little workshop on the property, comparable to the size of the ones I've had at my previous houses. It has no electricity, other than what I'm using right now which is a long extension cord. There's currently a GFCI mounted on the pool deck, about 20 feet from the shed that's on it's own, dedicated 20A circuit breaker from the main panel. It services nothing else and is fed via 1/2" PVC conduit that runs under a bunch of concrete and the deck. When I say under a bunch of concrete, I mean replacing it with something larger would require me tearing up my pool decking, cutting two sidewalks, part of a driveway, etc. Ideally, I'd love to run 1 or 1 1/2" conduit from the main panel but have the same situation so that's not a very simple solution. I have wired the building with 10 outlets, 2 interior shop lights and 2 exterior motion sensing floodlights for the yard / driveway and everything's brought back to a very small GE main lug subpanel with 1 15A (lighting) and 5 20A breakers in it, which I'll very likely NEVER use all of. This was wired for convenience outlets, maybe in the summer running a small window unit air conditioner and a few small power tools (drill, battery charger, etc and that's about it . The question I have is would it be feasible to repurpose the 1/2" conduit and run conduit from that junction box over to the shed, pulling 3 of the 12ga wires out and replacing with 10ga? Or am I being overly optimistic? I would say the run is somewhere between 50 and 100' total, but not completely sure of the path it takes so can't be certain on an exact distance. Also, would it be stupid to just put 30A service out to this building? Thank you in advance. Matt