5 ms·

Generators isolate themselves from the grid (unless they're installed extremely irresponsibly.) Part of the point behind solar is that it feeds power back to th

by swiley 5y ago

Generators isolate themselves from the grid (unless they're installed extremely irresponsibly.) Part of the point behind solar is that it feeds power back to the grid because the operators are the only ones with the infrastructure to deal with the excess.

Johnny555 5y ago
Grid tie inverters do the same, no power company would allow them otherwise. Generators don't isolate themselves, a code compliant generator will have a transfer switch that makes it impossible to backfeed the grid. The problem with generators is that anyone can buy one for a few hundred dollars and hook it up to backfeed their house without a transfer switch because a transfer switch is expensive to install and "I'll never forget to turn off the utility breaker before I turn on the generator" At least you need to get approval (and inspection?) from the power company before you can utilize net metering with solar, but anyone with basic electrical knowledge (or access to Youtube) and $20 can rig up a suicide cable to backfeed the grid from their generator.
- msandford 5y ago
  While that's true most generators are only rated for a few KW and most circuits they're hooked up to the bad, backwards way are several hundred KW i.e. their local grid that has been disconnected. So they would trip their breakers immediately and go offline or else stall or melt. Unless I'm missing something of course. Which is entirely possible.
  - Johnny555 5y ago
    If everything is working perfectly, then sure. But maybe that cheap 30A generator isn't running well enough to trip its 30A breaker and it's trying its best to backfeed 20A of current into the grid. Or maybe the other 5 neighbors on his pole transformer tripped over to generator or solar, so that one guy is able to power his pole transformer while the lineman is trying to work on it, or maybe he can't figure out why the breaker keeps tripping, so he keeps resetting it, only to have it trip again a second later, meanwhile he's sending surges of current into the grid. Utility workers will normally ground de-energized conductors before they work on them, but they need to do it perfectly each time to protect themselves from backfeeding.

by swiley 5y ago

Johnny555 5y ago

Grid tie inverters do the same, no power company would allow them otherwise. Generators don't isolate themselves, a code compliant generator will have a transfer switch that makes it impossible to backfeed the grid. The problem with generators is that anyone can buy one for a few hundred dollars and hook it up to backfeed their house without a transfer switch because a transfer switch is expensive to install and "I'll never forget to turn off the utility breaker before I turn on the generator" At least you need to get approval (and inspection?) from the power company before you can utilize net metering with solar, but anyone with basic electrical knowledge (or access to Youtube) and $20 can rig up a suicide cable to backfeed the grid from their generator.

msandford 5y ago
While that's true most generators are only rated for a few KW and most circuits they're hooked up to the bad, backwards way are several hundred KW i.e. their local grid that has been disconnected. So they would trip their breakers immediately and go offline or else stall or melt. Unless I'm missing something of course. Which is entirely possible.
- Johnny555 5y ago
  If everything is working perfectly, then sure. But maybe that cheap 30A generator isn't running well enough to trip its 30A breaker and it's trying its best to backfeed 20A of current into the grid. Or maybe the other 5 neighbors on his pole transformer tripped over to generator or solar, so that one guy is able to power his pole transformer while the lineman is trying to work on it, or maybe he can't figure out why the breaker keeps tripping, so he keeps resetting it, only to have it trip again a second later, meanwhile he's sending surges of current into the grid. Utility workers will normally ground de-energized conductors before they work on them, but they need to do it perfectly each time to protect themselves from backfeeding.