My family home (a new build from 1966) had (still does) two phases. It was because it used storage heating, so it has four fuse boxes, four ELCBs, and four meters ! On Peak Ph 1/Off Peak Ph /On Peak Ph2/Off Peak Ph2. All that lot takes up a monumental amount of space on the hall wall. My dad built a cabinet around it all.
My dad wanted gas central heating etc. Asked Southern Gas whether there was a gas main in the road. 'No chance, and probably never' he was told, so he went ahead with electric heating. 6 months later, the gas board turn up in the village and dig up the main road to install a gas main.
You can usually tell from the context - but there are some cases its a problem - like a conduit full of singles with both three and single phase circuits.
Neutral is connected to earth via a very large one ohm resitor at the generating station. The resistor is checked periodically to ensure it is one ohm.
And the charger is expected to extract equal amounts of power from each tin can.
The tin cans themselves come in different capacities. The transformer is relatively small and sits in the bottom of the can. The rest is oil and convection cooling. Like an inkjet cartridge, they can fit a different sized chunk of transformer iron in the bottom, as there is lots of room (normally reserved for the volume of oil desired). Inkjet cartridges have a lot of wasted space too.
If you go to the maintenance yard here, there's a section filled with spare tin cans. Hundreds of them. If you plan on using more electricity than at present, here they will do the can upgrade free of charge (because it's good for business). They only get upset, if you ask for more power than the distribution in the neighborhood can handle.
It will be interesting to see what happens when more BEV cars show up. How will they handle the upgrades, and who will get stuck with a fat bill of some sort ? I can't imagine free lunches being offered forever.
We don't have three phase in subdivisions here, so the three-can thing is academic. And the piddly charger here won't be as good as yours.
No it is provided for the distribution system. The site electrics will no doubt have a neutral for lighting and single phase stuff but it is ultimately connected to the generator earth. I once measured the the neutral to earth voltage at 2.6volts after generating a spark when reconnecting an earth lead to a metal chassis.
Same principles apply here, although in urban location a substation (i.e. big transformer[1]) will tend to supply a whole area, so loads (mostly single phase) will tend to be spread between phases. If you are a three phase user, then again you will be typically sharing a substation level transformer with many others, so in sum respects its less important to ballance the consumption between phases since your load is mixed with that of others.
[1]
formatting link
More rural locations with overhead supplies will tend to hole pole mounted transformers, although the use of spearate cans for each phase is not usuaully seen, and whole 3ph transformers more common:
formatting link
Something similar to the above would power say 10 - 20 homes and a few small businesses.
Its not only the local supply, but the actual generating capacity, that will be tested if/when there is a significant move from petrol/diesel to electric.
I expect most home chargers will be in the 5 to 7kW range anyway, since that will run from a single phase domestic supply without using too much of the total capacity. (modern installs are usually 24kW - 240V @ 100A), in older places 80, 60, and even 40A is not uncommon.
I used to install kit in betting shops for SiS. On one job a new shop had been created by knocking through the party wall between two units. The satellite receiver and decoder were in one half and the distribution amps and text computer and multiple screens in the other. There was an almighty 50Hz hum on the sound and hum-bars on the screens, it was obvious why but no one else had twigged. I cured it for the time being with an extension cable.
My sister used to teach in a small very exclusive private girls' school. They were doing some classroom renovations and discovered a boarded-up room between two classrooms amongst the chemistry glassware that was in there was a large beaker of a dull looking metallic substance half covered in oil. They called the fire brigade.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.