Phase converter question

[Joethemechanic]

It's not the distribution system, but the cost of upgrading every house! Most distribution feeding industrial/commercial is already 3 phase, even if the building owners chose at construction to be single phase.

If all new construction was done 3 phase I think the price of equipment would come way down. And most branch circuits would still be single phase. Just one more piece of wire, and one more bus, and you get 73% more power

Probably should up the voltage too 240/415 and then use european appliances

 

[egurdian3]

Savings from avoiding overloaded ckts, read house fires, alone, would save pile$$$.

 

[LarryFine]

Savings from avoiding overloaded ckts, read house fires, alone, would save pile$$$.

Not necessarily. Individual circuits won't be any different.

Services and feeders could still be marginally calculated.

 

[ptonsparky]

Savings from avoiding overloaded ckts, read house fires, alone, would save pile$$$.

I've about the only overloaded branch circuits in residential has been the kitchen in older homes. Even then, it was oversized fusing or CBs that caused problems. Three phase would not magically make any difference.

 

[Joethemechanic]

But just think of how much copper we could save with homes being served with 240/415 three phase. I mean if we are all going all electric, cars, heat, ranges ect.

Some people would want it just for bragging rights

 

[LarryFine]

But just think of how much copper we could save with homes being served with 240/415 three phase. I mean if we are all going all electric, cars, heat, ranges ect.

Some people would want it just for bragging rights

To be serious for a moment (hey, it could happen), let me think aloud for a moment.

We would save wire on branch circuits if we put twice as many outlets on the same ampacity circuit. That would mean halving the required number of circuits, but it would still take the same amount of wire to reach the receptacles, switches, lighting outlets, etc. Seems like a saving on breakers, not wire.

I have spoken with a few electricians in places with the higher-voltage wye systems, who told me that most homes were only powered line-to-neutral; supplied with only one line and the neutral. Major appliances could use smaller wire to deliver the same amount of power if they were powered line-to-line.

Added: I don't think there would be a great reduction of material usage at a higher voltage in the average home. Plus, the required infrastructure transition and asking manufacturers to produce dual-voltage and dual lines of products for years would be prohibitive.

 

[Joethemechanic]

if we put twice as many outlets on the same ampacity circuit.

The way I pictured it in my head, it would be the same amount of receptacles but using half the wire size with a 1/2 amperage breaker. Like your 15 amp circuit would now become a 7.5 amp circuit.

There would also be the savings on the service laterals and service entrance conductors. Just being 3 phase you increase the amount of power (in wattage) delivered to the panel by 73% with only a 50% increase in copper (or aluminum) used. Then you would also have the decrease in the amount of copper or aluminum needed because of the voltage increase.

It's not like we would have to worry about the tensile strength of the aerial service laterals for long spans, messenger wire has steel in it.

Although aerial service at 240 volt potential to ground gives me some reservations,,,But then again they do it in Europe

How many watts does a Tesla charger draw? I'll bet you could just about run one off of #12 copper if it was on a 415 three phase branch circuit

You could deliver 10769.25 watts on a 415 three phase circuit using 14/3 wire

 

[Frank DuVal]

If all new construction was done 3 phase I think the price of equipment would come way down.

Right, I was saying cost to retrofit all existing residences.

 

[going_commando]

I have a local restaurant that has a 3P dough mixer, the building is single phase, so they have a phase converter just for this machine.

I think it’s a rotary phase converter but I haven’t seen it yet, I’m going to look at it tomorrow.

Problem is that the kitchen staff turns on the converter to operate mixer but when they’re done they forget to turn off the converter so it continues to run, sometimes for days (apparently).
The maintenance guy thinks the converter is not operating like it normally should and Thinks that it’s because the thing is left on. He says the outer case gets hot enough to burn skin if touched.

I’m trying to think if there’s a way to have the converter automatically shut down when not being used. It obviously can’t shut down while being used or the dough will be ruined.

Can anyone offer any suggestions about doing this?
Thanks

If its getting that hot, check capacitors, check the bearings on the phase converter, and make sure its clean. We've serviced multiple rotary phase converters that just needed bearings.

 

[jdtm]

Probably should up the voltage too 240/415 and then use european appliances

Even if you match the voltages, there still is the issue that Europe uses 50 Hz frequency vs 60 Hz in USA, so unless you have equipment that is purely resistive, there will be problems running it.

I was hoping to see an update on the phase converter and find out how close the earlier guesses about the setup were. Did I miss it somewhere?