Just a Coincidence? - ECN Electrical Forums

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Here's an old Hubbell outlet and also a plug. It happens to be the
same pin pattern as plugs in Australia, as an Australian power
plug will plug into this outlet without forcing it. Note that the
Hubbell cardboard insert fits the Australian plug exactly. The wall
outlet
pictured is supplying 250V 60Hz each current carrying pin at 125V
from ground instead of 250V 50Hz in Australia where they have a
neutral
and one pin hot at 250V. Wonder if Australia got this style connector
from Hubbell or visa versa.... Australian loads are probably
designed
to not become dangerous if their outlets get miswired, the same as
American outlets can be. So any such Australian load plugged into the
Hubbell wall outlet should not mind the fact that both current
carrying
pins are hot (assuming it doesn't care about 50 vs 60Hz).

wa2ise

Hi there wa2ise,
That's a strange one you've dug up there.
Just a note about reverse polarity between the Phase and Neutral pins, it does happen quite a bit here with appliances and it usually only gets picked up if the appliance is repaired.
Australia as a rule uses 240V single phase, but for some strange reason, Perth in Western Australia uses 250V single phase.
Also bear in mind 'ise, that Argentina also uses this same pin configuration, not sure what voltage they use, but the Phase/Neutral sequence is opposite to the AS/NZ standard and the socket is installed in Argentina with the Earth (ground) contact facing upwards.
Any idea what that socket is rated at, current wise?, they are rated at 10A maximum here in New Zealand @ 230V

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Any idea what that socket is rated at, current wise?, they are rated at 10A maximum here in New Zealand @ 230V

The plug says 15A/125V or 10A/250V. Not sure why the lower current rating for the higher voltage. Unless when someone plugs or unplugs a load that is turned on, the arcing at the higher voltage causes more wear and abuse on the contacts.

I also have a few outlets and plugs using a similar pattern but slightly bigger. Just enough too big to be barely compatable with the above. Also 250V. But not a dryer plug. Smaller than those.

Seems like more than a coincidence. It would certainly be interesting to trace where the current Australian/NZ standard actually originated.

Regarding the polarity issue and running on split 120/240V supplies, have a look at the comments from this thread:
https://www.electrical-contractor.net/ubb/Forum9/HTML/000772.html

wa2ise,

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Unless when someone plugs or unplugs a load that is turned on, the arcing at the higher voltage causes more wear and abuse on the contacts.

We have switches on our sockets over here:

[Linked Image]

The extra switch is just a coincedence. [Linked Image]

Here's a single receptacle version which also accepts NEMA 1-15 plugs and is rated for 15A at 120V... this ones from Canada...

https://www.electrical-contractor.net/ubb/Forum17/HTML/000098.html

I still don't know what these were used for in North America...

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The extra switch is just a coincedence.

I've seen those in an Aussie catalog. Isn't that center swutch completely independent, so it can be used to operate a light, or maybe if a kitchen outlet it could operate a nearby garbage disposal?

That style of switch looks the same as that used on Clipsal brand fittings here (seen from time to time, but not that common).

This particular configuration is what we used to call a "Crowsfoot".

It's a NEMA 10-20, and is a 3 pole, 3 wire receptacle. 125/250 Volt.

The 3rd blade is for a neutral connection, and not a ground.

I haven't seen one in use in a very long time.

Yes Paul,
It's actually an HPM branded socket-outlet.
There's really not a lot of difference in appearance between the brands.
The centre switch is totally independant of the sockets and can be used to control pretty much anything, as long as you stay within the current rating of the switch mechanism.
When doing a job like this, it's common here to use what we call an "engraved mechanism" to identify what type of circuit the switch controls.
Thus:

[Linked Image]

from wa2ise

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electure,
I also have the 20A version, which I think is the NEMA 10-20 you mention. It's slightly bigger, as is seen in the pix below.
The 10A plug will (if you force it) fit the 20A outlet, but the 20A plug does
not fit the 10A outlet. Also the 10A outlet's ground pin is directly
strapped to the mounting yoke, so it can't be a neutral. However, the 20A
outlet "ground" (it's stamped "ground" on the plug pin) has its own screw
terminal and is not strapped to the mounting yoke. So that could be used as a neutral (physically, but is it code?).