this post was submitted on 17 Oct 2024
67 points (98.6% liked)
chapotraphouse
13517 readers
1156 users here now
Banned? DM Wmill to appeal.
No anti-nautilism posts. See: Eco-fascism Primer
Vaush posts go in the_dunk_tank
Dunk posts in general go in the_dunk_tank, not here
Don't post low-hanging fruit here after it gets removed from the_dunk_tank
founded 3 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
you could just have a big AC transfer switch that you throw or cable you plug to switch to generator or grid power. If you're trying to build this from easy off the shelf components that's going to be easier than trying to use the same inverter for both generator operation and solar, IMO.
3-way transfer switches seem to be uncommon, so probably expensive. I found this industrial one: https://www.psicontrolsolutions.com/wp-content/uploads/2024/03/Salient-MTSTB-Brochure.pdf . Just wire one input to grid, one input to generator, one input to inverter.
other, maybe easier, but less elegant way to do it is probably to feed the house from a big 50 amp RV style plug-in, and then just have a cable coming from each that you can swap between. If you're gonna do that you probably want breakers on both sides of the connection, at least for the solar setup and definitely grid inputs (generator you can just shut off I suppose).
Whatever you do its important to design it such that you physically can't connect two different AC sources to each other. You only ever want to be on one at a time. That's why you can't just use 3 plain old breakers (you could accidentally throw them in the wrong order and blow things up), that's what transfer switches are for, but that's not the only way to accomplish it.
this product line from bluetti is basically exactly what you're asking for and handles most of what you want for sure (not 100% sure about generator but you could add a transfer switch before or after the bluetti even if it has no special provision for it), and I assume there are probably similar products from cheaper off-brands, or you can always DIY a similar system with a bunch more effort: https://www.bluettipower.com/pages/ep800. Starts at like $6k but that's for almost 10kWh of storage and 7.6kW inverter with automatic failover, and it would probably qualify for a 30% tax incentive