US system is not as inefficient as I once thought

Oh, good grief, no. Most have more and many have far more than this. The house my parents built in 1959 had a 200A/240V service. Tract houses thend to skimp some, but 150A/240V is typical now.

Who cares about the entrance panel. I can buy a *huge* 200A panel for less than a couple of hours pay. The cost of the panel is insignificant compared to the cost of the house. This is a five-star *stupid* place to save money.

Putting up a warning sign is a poor substitute for removing the danger, and should only be resorted to when the danger is impossible to remove.

You would also have to hang a sign on every 240V appliance saying "Caution: this won't work if you plug it in in a hotel room, at your neighbor's house, or most other places."

Then you would have to hang a big sign on every extension cord saying "Caution: you MUST go to the other end of this extension cord and read the warning sign on the outlet it's plugged in to."

You seem intent on redesigning the US electrical system. A very wise man once told me, "If it works, don't f*ck with it."

Very wise.

No.. not intent on re-designing it... Just curious to know how it works and

..and I thought Americans were supposed to lead the world in everything.. computers, motor cars, space travel.. I've just *got* to stop watching television!

Cameron:-)

Cameron, old buddy, you folks don't use enough electricity to call it a system. The standard new home here has a 200a panel at 240v. You say only need 60 at

Lets' see.. two (maybe three on a big house) 20A power circuits, one (maybe two) 10A lighting circuits, a 20A stove (if it's not gas).. Yep, you're right, maybe we don't! ;-)

There is nothing in our Code (the SAA Wiring Rules:

Cameron:-)

My house cruises at 65 or 70 amps (240v) with the A/C on. I am using about 1.6 MWH a month and I don't have that big a house. That ends up being a $160 bill but it does include everything, including pumping water, heating it and cooking. When I turn on my spa the meter really goes around (2.5 hp pump, 11kw heater)

20 amps? A typical electric stove here in the US uses a 50 amp circuit. And this is with a 240 volt power supply. Unless Australian stoves are much more efficient than their American counterparts, 20 amps would only be good for a toaster oven and a two eyed hotplate. :-)

Robert

Alas, the leadership often consists of being first, then having to live with legacy decisions made by the pioneers while latecomers get to start fresh and learn from our experience. There are many examples of decisions that we are stuck with, such as the QWERTY keyboard, calling an excess of electrons "negative", etc. A few we have managed to partially redo, such as having no ground pin on our AC outlets or using 23 pins for RS232 when 9 pins are enough.

In the UK, a domestic supply would be 100A today. In an old house, it might be 60A or 80A, but providing your Consumer Unit (panel) is rated 100A and your earth bonding is up to spec (and the rest of the wiring not obviously unsafe), you can have the supply cutout increased to 100A for free. In the UK, people tend not to use electricity for space or water heating, and where they do, it is usually done mainly over-night into a stored energy system when electricity is cheaper.

If you want more than 100A, you have to go to a 3-phase supply, as

In the case of 240,/120 the US doesn't suffer much from the "legacy" effect.

ALL our big loads (more than 1.5 kW) ARE powered by 240 volts. The small stuff (TVs, lamps, computers, etc.) works quite well, thank you, at 120.

The ONLY issue is whether some outlets for 240 volts should be provided for the medium loads (500 watts to 1500 watts).

It would be reasonable for the NEC at some future time to require two 240 volt outlets in the kitchen just to encourage use of safer 240 volt appliances over the equivalent 120 volt appliance.

It goes without saying the US system with a maximum of 120 volts to ground is safter than systems with a maximum 240 volts to ground.

Now, now! QWERTY was "invented" so that alternant hands are used for most common letter combinations. Once learned, it is about as good as any other arrangement.

That wasn't a case of "redo." It was a case of the new and old being permitted to co-exist.

I read somewhere that you folks in the U.K. use power tools that run on 120 Volts (for safety) instead of 240 volts. Isn't this kind of awkward considering that your residential systems are essentially designed for one voltage (240)?

Seems to me that this would be an argument in favor of the US system whereby you can run most lighting and appliances (and power tools) on

One further thought. If an American accidently receives a shock from a faulty electrical device, it is far more likely to be a 120 volt shock vs. a 240 v. shock. Although 120 volts can still kill you, it hurts less and is easier to let go of then 240.

Beachcomber

I wired my lab with 60V two phase on my 120V outlets. Besides being safer, with 120V single phase, everything that has a line filter with a capacitor to ground induces a small current in the ground, which tends to cause hum in audio amplifiers, oscilloscopes, etc. With 60/60 two phase the capacitors in the line filters tend to cancel out.

I suppose the OP has never actually seen the RS232 spec. RS232 defines the 23 pin connector not the communications protocol. What we see in a PC is just a subset of RS232 signal set, suitable for the Asynchronous adapters they use. IBM adapted it to PC cards so they could make a combo serial/parallel card for the original PC AT and still get both connectors on the backstrap. When you start talking BiSync (another RS232 compliant protocol) you run out of pins pretty fast in a DB9

Construction site supplies in the UK are 110V, wired as 55-0-55 with centre-tap grounded, for appliances less than 4kW. This is for safety of workforce who may be standing in wet concrete or a muddy puddle whilst trying to use a handtool, which one of their colleagues might have just dropped into same puddle... A US 120V supply would not conform to our construction site regs as it exceeds the max permitted voltage to earth. The EU tried to make the UK drop it's 110V Construction Site rules, and I think as a result they are no longer mandatory, but in practice, that's still all you'll find on a UK construction site today.

A couple of years ago, I tried digging out relative figures for deaths due to electrical causes (it's difficult because different countries count things in different ways). However, I believe the figure per capita is higher in the US because electrical fires were more significant in the US than the UK. I would therefore speculate that that the higher current is more of a hazard than the higher voltage, although you would really need a better breakdown of the precise causes of electrical fires to be sure. Other factors might be quality of installations, maintenance of installations, quality of electrical fittings, use of alumin[i]um wiring, abuse of appliances, numbers of appliances, etc.

I suspect this has more to do with the American "do it yourself" mentality. It seems Europeans are a lot quicker to hire a professional. I have also seen notes here indicating that you folks don't have the big "home" stores with everything from 200a panelboards to meter bases that would seem to say it is OK for a homeowner to rewire his own service. Probably the scariest thing I see, as an electrical professional, are the number of "plug in" adapters, strips and cube taps, hanging on the wall at the grocery store that encourage overloading a receptacle. Add to that the small guage "zip lead" extension cords and you start to see how fire can become a problem. These seem to be marketed to those most likely not to understand the dangers. People who are living in places with sub-standard electrical installations are also those least likely to have smoke detectors, fire extingusihers and good egress routes. We do have issues but I doubt going to

You would suppose wrong. I have been working on RS232 hardware since I was a test technician on the original IBM plug compatable

Your error lies in confusing RS232 with RS232C. RS232 defines the electrical and physical standard. RS232C indicates that it is wired using a DB25 connector rather than a RJ45 or DB9 or some other connector.

EIA/TIA 574 defines RS232 on a DB9, using the following pinout:

EIA/TIA 561 defines RS232 on a RJ45, using the following pinout:

RS232C defines RS232 on a DB25, using the following pinout:

All are properly called "RS232" but only the latter is "RS232C."

...or the fact that it rains a lot in the UK...

Which HDA was too heavy "for one man to lift" ? I saw plenty of small girls swapping 3340 media.