Who would have thought

[Jim GM4DHJ ...]

[Jim GM4DHJ ...]

looks like a more sensible system .....

[Jim GM4DHJ ...]

ring mains are weird...tee hee

[Brian Howie]

Do you not mean "wired"

Brian

[Steve]

That gibberish means something?

[Jim GM4DHJ ...]

no

[Jim GM4DHJ ...]

yes

[Andrew]

The bloke at the end of the video said "ring mains are wierd" even though he did mention that immediately after WW2 metals were expensive so using 220/230/240 volts allowed for thinner cables.

do all American houses have to have an ugly great panel in the house like that one ?.

[NY]

For a given size of house and a given number of mains sockets ("receptacles") and light fittings, do US houses tend to have more separate circuits (and therefore circuit breakers) than a UK one? How about European, Australian etc houses?

Is there a tendency for there to be fewer sockets per circuit, and hence more circuits, if spur wiring rather than ring main wiring is used? Is the main advantage of ring main that it allows thinner wires to be used (at the expense of more length of cable) because there are in theory always two routes that the current can take to any socket?

Has there ever been a move to fit US new sockets with a pressure-operated switch that only makes the socket contacts and hence plug pins live once the plug is pushed fully home, in lieu of the partially-insulated plug pins that all new UK/European appliances must now have? Or is the risk of electric shock with non-shrouded pins seen as acceptable given the lower voltage?

[Tim Streater]

If you have something like a portable 2kW space heater in your US house, the cable it has is absurdly thick, to carry the 20 amps needed. And then it goes into one of their pissy little 3-pin plugs whose pins can be bent by hand. And when plugged it, the plug could be kicked out of the socket by a 3-year old.

[Paul]

That's a little too neat and tidy, I'm afraid.

A 4'x4' sheet of plywood, could be *filled* with devices. For example, you could have original-panel, upgrade-panel (more breakers), plus granny-flat-panel. (A house could have two kitchens.)

You need a whole house entry switch, to turn off the entire sheet of plywood in an emergency. Separate large loads sometimes have their own switches as well.

Telecom backup supplies may be nailed to the plywood sheet.

The board back home has an exploding cartridge fuse. It's never gone off. It flies out of the box and onto the floor, with the idea being "arc suppression" when disconnecting a large load. It would be pointless stocking a spare for that position, as it could be "stale" from sitting around for 50 years. I don't even know if you can still buy a replacement. No, it's not in the 200amp panel, it's a separate panel.

Electricians frequently come in, look at your sheet of plywood and shake their heads. But it doesn't stop them from bodging in another circuit, putting one more wire under a screwhead that doesn't have room for more wires, and so on.

This article is still a little too neat and tidy, but you can see how with little effort, you could get carried away.

Paul

[John Rumm]

Yes

and also yes, although not as many as the US since they don't need to wire extra 240V circuits in addition to 120V ones.

Yes, socket circuits need to be fused about 15A so that the circuit breaker can offer adequate fault protection to the circuit cables *and* the appliance flex (no plug fuses). So that means you only have 1800W available for the hole circuit. Hence lots of circuits with a small number of sockets.

That was the original design goal yes, You could take a pair of 15A radials as would have been common at the time, and turn them into one circuit with 7kW of capacity that can cover a wide area with lots of sockets. The plug fuse it what made it possible to safely power appliances with thin flexes from a 30A circuit, since you did not need to worry about providing fault protection to the flex at the main fuse.

I don't know. Although I would expect not since it adds complexity, lowers reliability and drives up costs.

I don't know, but the numbers killed in the US each year by electrocution are staggering in comparison to over here.

[williamwright]

It takes a special mind to make a crap joke like that!

Bill

[Andrew]

Plywood ?. what's wrong with OSB ? :-)

<snip>

Are there still really old Canadian houses where the internal wiring uses bare wires held on insulated pegs in the void between downstairs ceiling and upper floor ?

[Paul]

My grandmothers house.

Fortunately, the bulldozer got it :-)

I went down the basement stairs one day there, just a few feet (because the basement had an earthen floor and looks like a dungeon), and I saw some wires riding on standoffs... I turned around and got the hell out of there. I didn't want to discover any more electrical miracles. I don't really know what kind of fuse box it would have (it wouldn't have had breakers).

This is one of the benefits of grandfather clauses in regs - you can have terrible stuff in a place, and they can't force you to fix it.

But the bulldozer made sure nobody else lived there. After my grandmother passed at 92, the place was sold, but it was bulldozed right after that, and something new built in its place.

And we have older houses than that. My boss at work had a farmhouse. One with three foot thick stone walls for the foundation. But the inside of that was renovated, so it wasn't a hazard. The foundation was probably 150 years old. Some people can afford to fix the mistakes of the past.

Paul

[Tim Streater]

Knob and tube, I think they called it in the States. House I had in California in the 80s had a chunk of that along with lathe and plaster.