A $3.2 billion* thermostat....

No, that isn't true. All the fancy furnaces have proprietary thermostats that send some form of digital commands to control compressor and blower speeds. Pretty much all of them are incompatible with other makes, and often with other models from the same make. None of these furnaces will accept simple contact closure from a legacy thermostat.

Jon

A better question might be why the heck we don't have three phase in our homes.

Every time politics is mentioned on s.e.d?

Ahh, a Bridgeport in the garage. (almost heaven :^) George H.

If it has a huge thermal inertia, then what's wrong with using bang-bang control (a contactor) inside a PID outer loop? The whole thing will be slow as molasses anyway.

controller.

thermal inertia.

Excelently stated.

?-)

thermostat that can work with three-phase heater (each phase 1.5kW)? I can not find thermostat with PID and three phase thyristor controller.

Where i grew up a neighbor down the block had a Bridgeport and a lathe of similar class. Had a nice side business knocking out parts to mil spec. His son was one of my few close friends.

?-)

Really now? Cite some brands.

It's not a wound, it's a feature...

Had an old boss, he had Bridgeport in garage. He started knocking parts out to some spec for subs. He actually retired from former shop. Last time I heard, he had over a dozen employees making submarine stuff. He used a motor generator in his home garage when the whole thing started.

Greg

George Plue (RIP), who had the last fully operational SDS Sigma 9 and Sigma 7, told us he bought the house in Flagstaff AZ because of the location. He knew at that location, he could get 3 phase power brought in to run the machines.

Cost. Need.

It pushes a bunch of costs onto hundreds of millions of homeowners, who don't know they need it. It would be nice to have 3-phase motors everywhere and not to need fat short-lived electrolytic caps all over the place.

Best regards, Spehro Pefhany

I think they went about 75 years with the lion's share of residential loading consisting of lights and heater elements. The motors, if any, were used infrequently and mostly fractional HP stuff.

The payback time for those three (or fewer) motors in the homes of those "who don't know they need it", is?

Probably only a few years, if it was widely implemented so costs were pushed down, like retrofitting LED street lights.

But it's not as easy, as it would require new appliance designs to take advantage of the potential savings, so there's a chicken and egg situation. All commercial and industrial installations, almost without exception, use 3-phase power for lighting, motors, ovens and so on.

Best regards, Spehro Pefhany

My last electric bill was $65.87. If it was 10K and up, three phase would make sense. I don't use anywhere near the monthly minimum for three phase service to be offered.

How? Even the crappy single-phase motors last decades.

Don't buy it.