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Comment on Twenty four US states are now considering legislation to allow small, plug-in solar power systems that connect directly into a wall socket.

officermike@lemmy.world ⁨8⁩ ⁨hours⁩ ago

I am not an electrical engineer, but based on OP’s description, it sounds like a solar panel that connects to an outlet in an existing circuit. Say you have a solar panel plugged into the first outlet on a 15-Amp circuit, with solar producing 1200 Watts of available power. Then you have a 10-Amp load plugged into the next outlet in the circuit, and another 10-Amp load plugged in further down the circuit. That 15-Amp circuit has wiring rated for 15 Amps. You have 20 amps of load, but the solar panel is providing half of that downstream from the circuit breaker. The breaker sees only 10 amps of load and doesn’t trip, though you have wiring downstream from the solar panel that’s carrying 20 Amps. This will start a fire.

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usernamesAreTricky@lemmy.ml ⁨8⁩ ⁨hours⁩ ago
In Germany, they limit to more like 800 watts (and I think some other safety regulations). As I understand it, it’s generally worked much this being much of an issue despite millions of plug in solar installs

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Lemmyoutofhere@lemmy.ca ⁨7⁩ ⁨hours⁩ ago
I think you need to learn how electric circuits work.

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- officermike@lemmy.world ⁨6⁩ ⁨hours⁩ ago
  I’ve had more than a few classes on circuits throughout my schooling, from high school physics to my mechanical engineering college coursework. Please enlighten me as to where my logic is flawed.
  
  Two sources wired in parallel can supply more current than either individual source can supply on its own. The wiring on each parallel branch will have identical voltage, and the converged branch will carry the sum of the currents. Total load of 20 amps exceeds the capacity of the wiring, breaker doesn’t see the full load and doesn’t trip.
  
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pelespirit@sh.itjust.works ⁨8⁩ ⁨hours⁩ ago
The solar panel would be providing some of that electricity though. You’re not accounting for that.

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- officermike@lemmy.world ⁨6⁩ ⁨hours⁩ ago
  I am accounting for that, that’s the whole point I’m making. Breaker is supplying 10 of its available 15 Amps, solar provides another 10 Amps, load downstream is drawing 20. Wiring between solar and load is carrying 20 Amps, but potentially rated for only 15.
  
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