[Scoundreller]

What makes it easier on 240v systems is that your entire household is on the same “circuit”.

If you’re on a 120v system, there’s a ~50/50 chance that your load is on the wrong side (except for 240v loads where you’ll imbalance things a tad but it should average out).

Unless you’re in an apartment/conso and have 208v instead of 240v… dunno what happens then.

[bob1029]

Every US household has at least some big circuits across both lives. You could theoretically put the battery in the laundry room and use the 240v outlet. This is effectively what I did when my power was out during a hurricane. I backfed my entire house through my laundry room. Not to code but nothing was that week. The circuit wasn't rated for enough to handle the HVAC load so I eventually installed a separate 50A inlet on the side of the house.

[toast0]

> Every US household has at least some big circuits across both lives.

Not really. My parents have all natural gas for the furnance, oven, stove, clothes dryer, and water heater; no air conditioner. Everything else is lights and outlets. There are no 240v outlets and no 240v breakers other than the main breaker.

[Symbiote]

This is true for the British system, except for the largest houses (6+ bedrooms) where you'll have a three phase 415V supply.

Elsewhere in Europe it varies. Even small properties in Denmark and I think Germany have a three phase supply, my oven and stove use it directly.

[angry_octet]

There are multiple circuits on each phase, you would still need to limit current per outlet to 10A (8A sustained). If it's a dedicated circuit then 15A is fine, but usually that means a separate run, and in that case you can just have 20A or 32A.

When you have "three phase 415v", the 415v is the phase-to-phase voltage. Unlike the US 180 degree split phase 220v or 208v p2p, consumer equipment is not wired phase-to-phase unless it is 3-phase.

It's interesting that Europe has 3 phase cooktops, we usually see 32A single phase in Australia, homes rarely need more than 7kW per circuit. Aircons, pool heat pumps and EV chargers are the 3p loads.

Getting a 3 phase PV inverter is worthwhile if you have sun synchronous loads, like pool heater/chillers, across the phases. Then you will want a 3p battery inverter for the same reasons.

[angry_octet]

It would be very unlikely that your 240v system would all be on the same circuit, unless you have an antique UK ring main.