From the 1940 Catalog X of H&H wiring devices. Look at #7445, Aussie plugs would fit. And plug #7440 would fit Aussie power points.

Interesting find. I knew the design/patent was American, but I had not seen evidence of their production.

These were made, I have a few installed in my house, to provide my Aussie radios with 240VAC. The radios are perfectly happy with 60Hz.

Earlier Aussie plugs also had prongs contour shaped like those in types 7440 to 7848!

Interesting that this form was adopted as the standard for domestic 220vac in China - though in buildings older than 1950s other standards were in use. The chinese plugs had a slightly larger earth pin than the current Australian 240 5amp domestic plug - so they did not fit Australian sockets when I brought some back (1980s). That gives our "scream" plug a good chance of eventually being the most common world-wide, perhaps to the horror of others who consider themselves world standard-setters !

Maven

It wasn't originally a sad face/scream here until it was turned 180 degrees, so that the earth pin points south.

In my grand parents house, built in the late 1930's, the power points were oriented with the earth pin pointing east. In my parents house, built in 1950 the earth pointed north and newer points added to a later extension to that house had the earth pin pointing east. This photo sums up the situation nicely, from left to right:

http://members.iinet.net.au/~cool386/plug/orientation1.jpg

Interesting point - I wonder what was the logic of that lateral orientation? 2-pin plugs most commonly have active and neutral in horizontal rather than vertical. It must be documented somewhere.

The other great divide is the standard switch position - US standard is up=on, where most others seem to be up=off. Very confusing when fumbling jet-lagged in the dark of a US hotel room.

Just an observation.

I've noticed that on domestic power boards, with circuit breakers, that up is always on.
The main switch (isolator), will be down for on.

I have not seen a deviation from this standard?

Wayne

HPM briefly made circuit breakers that were up-off down-on that plugged into Federal fuse blocks but these did not take off for long as soon after laws came in banning the installation of rewireable fuses, thus making the fuse blocks obsolete.

Email was by far the largest circuit breaker manufacturer Australia had and they mostly used Westinghouse (US) designs under licence, which meant that the toggle action was the reverse for Australia's light switches. Large form factor circuit breakers have a different action to the typical switch too. When the breaker trips, the toggle only moves halfway along its travel. This way, the electrician can see that the breaker tripped rather than being simply turned off. The breaker is then reset by switching off then on again.

In switchboards with the DIN rail form factor, which is generally the most popular type now, the circuit breakers are mounted on their side making the switch action horizontal. This also makes the argument about it being safer to throw the toggle down in an emergency obsolete.

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A valve a day keeps the transistor away...

QUOTE: US standard is up=on, where most others seem to be up=off. Very confusing when fumbling jet-lagged in the dark of a US hotel room.

It's consistent, for the USA and Australia, if you think of it being: on is towards the North Pole, off towards the South Pole. Just like when you drive east on an east-west road, use the side of the road closest to the Earth's equator.

For extra fun, if the light is controlled by two switches, then it is random at any one switch, depending on what the last user did.
The X in the circle symbol is the light bulb.

American outlets don't have power switches on them. And I noticed on my holiday to Australia 25 or so years ago that Aussie outlets/powerpoints didn't have any mechanical interlocking mechanism to prevent me from plugging or unplugging something while the switch is left on. In the USA, the switch thus would be considered as pointless, from a safety viewpoint. We try to protect our idiots...

In some cases unfortunately, idiot protection is actually rife here as well. They have introduced a plug with around 3/8" of sleeve adjacent the plug body on N & A to stop fingers & knives used as a crowbar from becoming alive.

All of the "new" installations and any old ones that have to have work, or additions to them have to be fitted with a "Residual Current Device" which is a Sunday name for a device that detects earth leakage & trips if there is an imbalance between N & A. Like when some moron sticks some thing conductive in the live terminal.

Was it not Mark Twain's Mother that thought that electricity leaked out like water, when the switch was left on?

That above looks like the standard hall light circuit.

With valves & things the Insurance House "Lloyds of London" I believe specify that a valve & other things. Must fail safe: Usually off.

Marc

As Marc mentioned, two way switching is often installed in household hallways but is also commonplace in commercial installations. As indicated in WA2ISE's circuit diagram this involves connecting two standard mechanisms with a pair of straps (this is what the twin cable between the switches is known as in the trade). There is a second type of mechanism known as an intermediate switch and an unlimited number of these can be wired into the straps to cross over the connections and this provides extra switching capability in function rooms and long corridors.

The only downside to this method is that whether the lights are on or off, some switch dollies will be up and others down. This can be resolved by using the newer pushbutton mechanisms which resolve the debate by removing traditional switch dollies altogether. Pushbuttons are more common in homes with C-Bus connectivity, which permits soft starting of both incandescent, fluorescent and LED loads, automatic switching of lighting and appliances and remote control of the same.

Regarding safety and duty of care, the general principle is that when someone injures or kills themselves it is always someone else's fault. People are no longer bred to take responsibility for their own actions though in some ways this is changing. The NSW Government has abolished being drunk or stoned as a defence for committing crimes and those who, for example, assault someone and then try to claim diminished responsibility will be in for a shock when they face the beak. It will be years, if ever, before the same idea applies to OH&S and at the moment the chain of responsibility still puts the bosses directly in the frame for everything from a scratch on a finger to industrial manslaughter.

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A valve a day keeps the transistor away...

Delete

I didn't see GTC's link until now. Those outlets were quite commonplace between the 1930s and 1960s. The one on the left emulates the US standard pattern. and their accessories are still made this way, to my knowledge. The socket mechanism in the first photo was either as pictured or vertical depending on the brand. HPM, Ring Grip, Wilco, Elmaco and Clipsal (plus a few others) made socket and switch mechanisms and plates for the standard pattern wall boxes. Some were plain, as pictured, and others had art-deco patterns. Black, brown and white were the only colours I know of.

The middle photo shows a socket outlet that seems to be some sort of limited edition. They weren't as common as the others and appear to be a 1950s vintage. The photo on the right shows an early example of what we have here today. These were a precursor to the accessories fitted with 'allways' mechanisms that could be oriented horizontally or vertically, as needed.

http://www.electrical-contractor.net/forums/...

The link above leads to a version of this outlet fitted with safety shutters, mechanism interlock (as WA2ISE described) and an extra switch. Such outlets are fitted in wet areas and the extra switch usually controlled an exhaust fan. Mechanism interlocks aren't commonplace these days and shutters are only required in specialised situations such as pre-schools.

Technically, none of these outlets are legal now. That is, those that are still in service are still legal but once they are replaced they must be replaced with one that meets current AS3000 (SAA Wiring Rules) requirements. The first could be legal if the socket was changed to one that was oriented vertically as AS3000 requires the earth pin to be at the bottom.

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A valve a day keeps the transistor away...

http://www.electrical-contractor.net/forums/ubbthreads.php/...

This is an interesting US socket, no doubt for the area the telly or radio is placed in the home. The top socket is for antenna/aerial and earth leads and the bottom one for the mains supply. It reminds me of back when we were allowed to pop the extra switch on a double outlet and fit a 75Ω PAL socket in it's place. Standards were changed in subsequent years to prohibit this as the home handyman was leaving shielding from the coax lead to touch poorly connected mains wires, thus receiving a shock when they touched live parts of their appliance. Current standards require antenna sockets to be on separate plates to the mains sockets.

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A valve a day keeps the transistor away...