3 ms·

NEMA 6-15 and 6-20 seem to be pretty uncommon. This is no doubt in part because most stuff we run on 240 in the US is higher amperage anyway, and probably in pa

NEMA 6-15 and 6-20 seem to be pretty uncommon. This is no doubt in part because most stuff we run on 240 in the US is higher amperage anyway, and probably in part because some stuff also wants a neutral? The only NEMA 6 I have is on my table saw, and maybe the planer? Everything else is NEMA 14 (two hots, neutral, and ground). The upside of that is the bulb in your dryer, for example, can be a standard 120 volt bulb. I'd also like to note that the locking connectors plug and unplug a hell of a lot nicer than the non-locking ones, at least at the 30 amp size (which is common for a dryer). They just operate much more smoothly, presumably because they aren't relying on friction to keep them plugged in.

xenadu02 1y ago
> This is no doubt in part because most stuff we run on 240 in the US is higher amperage anyway, You've got the cause/effect backwards I think. The high amp stuff needs 240v to avoid ridiculous amp requirements. The lower power stuff just defaults to 120 because that's the most compatible leading to the chicken-and-egg problem. > probably in part because some stuff also wants a neutral? I've tried to come up with reasons this might matter but so far I can't. The Neutral (or really L2 in this scenario) is the reference plane. It moves in step with L1 and so when L2 is high (+120) L1 is low (-120), but from the POV of the reference that's just -240. Same for the other cycle half. In other words measuring voltage is relative in all cases. Unless you are measuring in relationship to the earth (an infinite sink for our purposes) you can't tell if you are seeing +120/-120 or +240/0. Perhaps there is something that relies directly on the voltage potential between Line and Ground, I just don't know of any. Most things that are sensitive to an actual ground reference are electronics which run on DC and are separated from the mains by their power supply anyway.

xenadu02 1y ago

> This is no doubt in part because most stuff we run on 240 in the US is higher amperage anyway, You've got the cause/effect backwards I think. The high amp stuff needs 240v to avoid ridiculous amp requirements. The lower power stuff just defaults to 120 because that's the most compatible leading to the chicken-and-egg problem. > probably in part because some stuff also wants a neutral? I've tried to come up with reasons this might matter but so far I can't. The Neutral (or really L2 in this scenario) is the reference plane. It moves in step with L1 and so when L2 is high (+120) L1 is low (-120), but from the POV of the reference that's just -240. Same for the other cycle half. In other words measuring voltage is relative in all cases. Unless you are measuring in relationship to the earth (an infinite sink for our purposes) you can't tell if you are seeing +120/-120 or +240/0. Perhaps there is something that relies directly on the voltage potential between Line and Ground, I just don't know of any. Most things that are sensitive to an actual ground reference are electronics which run on DC and are separated from the mains by their power supply anyway.