The middle photo shows a socket outlet that seems to be some sort of limited edition.

In my parents' house, they were white/cream (possibly painted) and mounted in the skirting boards. I think you'll find they are HPM or Clipsal.

US uses more smaller pole transformers, UK uses fewer larger transformers.
Don't know why the different philosophy because both distribute 240v to homes!

QUOTE: Don't know why the different philosophy because both distribute 240v to homes!

It may be that American homes are more spread out than those in the UK. And that it's cheaper to use many small transformers than to have heavier wire to distribute the 240V to all the spread out houses, to keep the voltage drop to a minimum to the houses at the far ends of the 240V lines. Also, as the average price for electricity here is around 12 cents a kilowatt hour, we are probably more power hungry...

QUOTE: Current standards require antenna sockets to be on separate plates to the mains sockets.

In the USA, antennas, catv, and phone lines are prohibited from being in the same electrical box that has power wires. Signal lines for ganging smoke detectors are allowed, but that wire needs to have the same thickness of insulation as the power wires, or something like that. I wouldn't want the radio antenna wires near power wires anyway, else I'd be picking up interference from the mains powerline. Oh, I could create a 2 gang cover plate that has cutouts for a power outlet, and a CATV connector, but the CATV connector feed coax needs to be going through a hole in the wall, so it is outside the electrical wiring box that houses the power outlet.

Though the US transformers have split loading, this should balance out by the law of averages? So same wire gauge/homes ratio as UK, AU? Heavier wire gauge required only in houses for 120v arms, slightly less in Mexico using 254/127v.

I gather the USA runs a higher voltage (at least 2KV?) to the 'pole pig' than we do here where suburban streets typically have 3-phase and neutral 415 volt lines running past the houses from a 415 volt pole transformer (or kiosk transformer for underground services) somewhere in the neighbourhood, and so on back up the voltage chain until many KV at the distribution station.

Single phase 240 volt domestic services are tapped off the 3 phase 415V lines in a balanced manner (i.e. alternately shared across the 3 phases) and any 3 phase services are (naturally) connected to all 3 phases in the street.

There are some photos of this arrangement somewhere on this site.

We in the USA have 3 phase 13.8KV/7.9KV "feeder" distribution, and pole pig transformers that step that down to a grounded centertapped 240V (makes for a pair of 120V lines). Most single family houses get single phase 240 V with a grounded centertap, usually at 100 amps. Though we usually don't draw that much current. This is a 50KW transformer serving 8 houses, fed by one of the feeder phases.

In the rural area around here we have 2 phase at around 24KV this eventually for some parts ends up Single wire SWER. The major issue I have with it is the amount of RF those aerials drag in.

I am being pedantic but 240VAC + 240VAC from a 3phase system = 415 due to Cos Theta, as it is a vector sum.

Marc

If you want to be pedantic, officially it's now 230 + 230 = 400.

Mine system seems to have escaped that at time of writing is about normal at 246V albeit there is currently not a huge load on Fridge may be idling Studio is only running a twin 85 Watt light & a 40Watt plus the computer & its bits.

Doubt the load is more that 500 Watts

Marc

In reality it's still 240V+, but Australia got into line with the IEC and our voltage range tolerance is supposedly 240 +10%, -6% (264V - 226V).

Over voltage is my usual experience with the voltage in my workshop (in an industrial area) sometimes close to 250V. Can't say I've ever seen it below 240V.

So much for imported products expecting a nominal 230V.

Medium and high voltage networks in Australia generally follow this plan. 23kV from the power station up to either 132kV, 330kV or 500kV, down the major transmission lines to zone substations where the voltage is lowered to 66kV then down to 33kV or 11kV, then fed to local substations either pole mounted or in kiosks where this is lowered again, finally, to 415/240v.

AS60038 states Australia's nominal supply voltage though it has never officially been adopted - in terms of cranking the voltage down at substaions. It's just a piece of useless paper in reality because, as has been mentioned elsewhere here the voltage can vary greatly, depending on whether it is summer or winter, midday or midnight, wet or dry, etc.

When I've put the meter on a circuit for testing, I've never seen below 234 volts or above 256 volts from an active to neutral. It's a little silly that on paper we fall inline with the EU when most of our imports come from SE Asia, with voltages ranging from 100 volts in Japan to 220 volts in South Korea.

Back to how useless this "standardisation" is, I seriously doubt the US and Canada will raise their actual supply voltage to 120v anymore than we'll lower ours to 230v. There are websites devoted to the cause. They are put together by people with little else to do with their time. Most middle and high range electronic appliances made now can be plugged into any AC supply in the world and work correctly.

If the supply voltage here was lowered, it would increase current flow on the 'last mile' networks, then another group of gabfesters would have to get together and lower all the current carrying capacities of domestic wiring to suit.

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A valve a day keeps the transistor away...

I seriously doubt the US and Canada will raise their actual supply voltage to 120v

I've read posts elsewhere by some Americans complaining that their local supply has steadily crept up over the years to a regular 125 volts, and the consequences that has for some vintage 110 volt radios.

I have a lot to do with the forum. http://antiqueradios.com/forums/index.php

In some ways the Americans brought the radio burn out problem on themselves. They raised the voltage on the mains.

Most of the early stuff was designed for 110V and a lot of sets had no transformer. Even when they did, unlike Australia, very few had tapped primary's. Many of the Zeniths seem to be quite marginal & are one that seems to have a lot of issues with transformers. At least ours by having taps (normally 3 from 200VAC to 260VAC had a bit of a chance as you could vary the tap to suit the area.

One of the more interesting locally were some of the early AWA sets where there was a fuse in common and another in the active & you changed the tapping by moving the active fuse.

Two fuses was not silly as often sets had two wire cables & were wired any which way & even into light bulb sockets (light music/ entertainment?) so you actually had no idea which was the hot wire, as it could change every time the set was plugged in.

I am not sure that is intentional, although intentional or not, radios designed for 110v won't like 125v all that much. It is much the same situation as in WA, where the mains voltage can exceed 260v because it is not regulated as well as the grids in the eastern states. Because of WA's isolation it is not connected to what could otherwise be regarded as a national grid comprising NSW, VIC, QLD, SA, TAS and the ACT. The NT is also isolated, with most of its small communities powered by diesel motor-generator sets.

Back when Australia had a light globe factory, special globes rated at 260v were made for the WA market to cater for the wild variations in the supply. I recall some of my AWA sets had the fuse blocks on the back of the chassis to select input voltage too. My R27 Radiolette is one such beast. Sadly, the socket that fits over these fuses are rarer than the radios themselves.

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A valve a day keeps the transistor away...

QUOTE: 240VAC + 240VAC from a 3phase system = 415 due to Cos Theta, as it is a vector sum.

QUOTE: officially it's now 230 + 230 = 400

Sounds like you have, for larger customers, a 3 phase Y system. We have the same thing, thought at half the voltage, 120 + 120 = 208.

Various methods for commercial/small industrial customers


Our power companies prefer to do this:

All legs are 120V to neutral/ground. But phase to phase is 208V, so a load wanting 240V will be undervoltage.
Sometimes, apartment houses will be fed this, and individual apartments will be fed 2 of the 3 phases. Electric ovens and dryers will take longer to get warm (consumer appliance makers don't bother with 208V models, too small a market, and someone will mistakenly connect one to 240V anyway)..

An older method, our power companies don't like this anymore:

One of the phases is centertapped 240V, to provide for 120V loads. The 3 phase loads don't care where the ground is. For smaller customers, the power company will omit one of the side transformers. A drawback of this is that one of the lines, the "wild leg" is a higher voltage, 208V. People sometimes add a circuit to this line by mistake, thus blowing up something expecting 120V.

And most single family houses get this:


I feed my Aussie radios with the 240V, across both 120V lines.