River Bank is the stackable battery for everything you power, everywhere you go | 220v Contactor Relay

It should be mentioned that any of us that have been working in commercial/industrial settings should be familiar and certified under NFPA70E. This includes, but is not limited to, how to work as safe as possible with hazardous energy sources, what the proper protection is for various levels and what is considered “safe” (working distance, approach distance, protection level, etc).

Mains powered heated glass plates are common place in catering, same deal as a car back window, the heating wires are on the other side from the “working surface” these things can tolerate touching and even fluid spills, why reinvent the wheel, the solution is already commercially avaliable.

That’s how you may get some serious, even life-threatening, internal RF burns without noticing anything.

That works, it’s a couple of hours work with an RFM12B. And it’s write-only, so you can’t read the status (so no confirmation it actually turned on/off).

That said, why not use 12v halogens (or even mains voltage halogens) to provide the heat? They are ~99% efficient at that, cheap, plentiful, universally available…

The farther I need to travel to get to you, the more time is taken out of my day—and I’ll factor that into your bill. Finding someone closer to your neighborhood might be able to charge you less.

A vaccum forming table design I looked at used ceramic rods made the same way with reflectors to evenly distribute the heat. I also own an electric kiln designed to heat and temper glass so a page can be taken from that design.

I think Brian’s point was that if the bond between the earth ground and the neutral return of the incoming premises power isn’t good enough, then the short to earth might *not* trip the breaker. Of course, it would likely start a fire instead (the resistance may not be zero, but it will be low enough to sink a great deal of power in most cases and a 15A breaker will tolerate a couple THOUSAND watts), but I think that if you can’t trust that the building is to code, then all bets are off.

Yup. That’s how you install an outlet for a big dryer or a welder or something than needs the extra power. Never occurred to me to utilize it for a computer PSU, but I suppose it’s pretty nice when you need to squeeze out every little bit of efficiency.

Good safety design will deliberately include a point (usually mains input) at which the creepage clearance is lower than any other place on the circuit board. This almost guarantees a *predictable* result from an extreme over voltage event.

There are split-phase premises supplies and three-phase. Split-phase is used for residences and small businesses, and three phase is used for larger businesses and some larger multi-tenant buildings. When using two of three phases, they’re 120 degrees apart and the nominal voltage is 208 volts. When using both sides of split-phase, the two are 180 degrees apart and the nominal voltage is 240 volts. The nominal voltage from one phase to neutral is 120 volts.

Knocking over a candle would be an accident. Keeping barrels of petrol in your living room would be negligence. Doing your own mains wiring without the proper qualifications, I dunno which side that falls on. Real accidents can’t be foreseen, but you have to take reasonable precautions.