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[Lyle Williams]

Australian mains plugs now have insulated pins (insulation covers half the length of the L and N prongs) to mitigate the risk of things slipping between the power outlet and the plug.

Chinese power outlets have nearly identical geometry to Australian outlets except they are installed "upside down" with the ground pin at the top to reduce the risk of something slipping into the outlet/plug gap.

The logic around the Australian orientation was that a common accidental disconnection (such as stepping on the appliance cord) would result in a downwards force; with the ground prong at the bottom ground will disconnect last in this scenario.  In any case, the ground prong is also longer than L and N to ensure it is the last to disconnect.

[Frank DeWitt]

Ground up  Check
Ground down Check

[Stephen Swaffer]

Appears that he intends to ground the plug to the outlet box. Hoping that it's metal, of course...

Sheetrock wall, wood framing, NM wiring-"grounding" to metal box or pvc-same difference!

Love to see them try to get this one installed the right way!  Receptacles rotate however you want them-I don't really like them, but they are UL listed and if you have 2 cords to plug in with 90 degree plugs and the same ground pin orientation about the only way I know to do it in a single gang.

[Jeff Bankston]

And I wasted all those years studying electrical engineering... Who knew you didn't have to keep track of the wire or screw colors? 

Here's another one where he's more interested in the colors of the wall plate than the actual safety ground. http://www.youtube.com/watch?v=bnGERqjgrzA

When I first started writing about RPBG wiring (Reverse Polarity Bootleg Grounds) the test gear manufacturers had the gall to ask me how they could happen. These guys are proof of just how dangerous the DIY movement can be without proper training. Yikes!!!

wait till they come upon some of that old wire with the rubber and cloth insulation. the insulation usually disentergrates.

[Jeff Bankston]

These guys fixate on unimportant details like the color of the wire nuts or orientation of the outlet.  The orientation of the receptacle (ground hole top or bottom) isn't specifically established by the NEC. In fact, there's been an ongoing discussion that orienting receptacles with the ground contact on the top might be safer, considering that a metal outlet cover with a lost screw would fall down on the ground pin, and not short across the hot and neutral blades of the plug. Don't know if there's been a consensus in the 2014 code release, but I'll take a look when I a get a copy. 

Too much fun! 

sometime during the 90's california required the ground to be on top. it came about when an office caught fire and a few people were killed. the investigators determined that the cause was caused by a paper clip that fell behind a desk and fell right on top of the hot and neutral of a plug that wasnt pluged all the way in to the receptical. they found the circut breaker had not tripped and that the short became hot enough to ignite the plug,wall plate and wall paper. they said the old wall paper was very flamable and was the glue. it spread quick and trapped some people. there were no sprinklers. after some test they found that if the ground prong was on top and the plug wasnt all the way in any metal that fell on it would fall off. some years later the inspectors told us we no longer had to put the ground hole on top. further testing revealed that if a metal object like a paper clip hit the ground prong and rotated and hit the hot while still touching the ground it would weld itself to both and a fire could still happen. 

[Greg_Cameron]

sometime during the 90's california required the ground to be on top. it came about when an office caught fire and a few people were killed. the investigators determined that the cause was caused by a paper clip that fell behind a desk and fell right on top of the hot and neutral of a plug that wasnt pluged all the way in to the receptical. they found the circut breaker had not tripped and that the short became hot enough to ignite the plug,wall plate and wall paper. they said the old wall paper was very flamable and was the glue. it spread quick and trapped some people. there were no sprinklers. after some test they found that if the ground prong was on top and the plug wasnt all the way in any metal that fell on it would fall off. some years later the inspectors told us we no longer had to put the ground hole on top. further testing revealed that if a metal object like a paper clip hit the ground prong and rotated and hit the hot while still touching the ground it would weld itself to both and a fire could still happen.

I've seen a guitar string laying over someone's amp in a practice room fall off the amp and land across the hot and neutral of the amp's plug in the receptacle. Made a nice flash and burn but did trip the breaker.

[Steve M Smith]

That highlights a flaw in northwestern-half-hemisphere (what do you call half a hemisphere?) electrical design: a plug partially removed exposes live electrical contacts.

Not the UK plug.  It is half insulated so that if it is inserted just enough to make contact, only the plastic parts are exposed on both live and neutral.



(quadrasphere?).


Steve.

[Mike Sokol]

Not the UK plug.  It is half insulated so that if it is inserted just enough to make contact, only the plastic parts are exposed on both live and neutral.

The American "Edison" plug can also be a shock hazard across your fingers if you slip while plugging it into an extension cord partially. I do like the Neutrik PowerCon connectors that Whirlwind uses to interconnect their PowerLink product line.

[Mike Sokol]

Back OT. Here's a video for dummies who need to replace an existing electrical outlet. It's not terribly bad, except for two glaring mistakes and some lack of info.

http://www.youtube.com/watch?v=vfZAE1VQPEY

#1 They don't have you test the meter first to see if it's working before turning off the circuit breaker (actually a 3-light cube tester would be better for this, I think). If the meter was set improperly, then it would show zero volts even on a live circuit.

#2 There's a lot of bare wire extending past the screws and looks like it would contact the side of the box. I always make sure any bare wire is trimmed back tight to the screw head, plus add a few wraps of electrical tape around the receptacle to insulate the screws from any accidental side contact. 

#3 They don't mention what the breakout tab does, which of course is for a combo switched/unswitched receptacle.

[frank kayser]

When I first started writing about RPBG wiring (Reverse Polarity Bootleg Grounds) the test gear manufacturers had the gall to ask me how they could happen. These guys are proof of just how dangerous the DIY movement can be without proper training. Yikes!!!

Maybe some common sense would help. It does not take an EE to replace an outlet properly.  Pay attention and put things back the way one finds them (assuming it was correct when approached).  Unfortunately, most of the remaining common sense is either educated, trained, or litigated out of the populace.  (sigh)

As for outlet orientation - in new construction - how about a sideways orientation of the box and outlet so neutral is up.  With a 3-prong, the hot would be well shielded, and with two prong, it would be that much tougher for an accidental short beween neutral and hot. Of course, if the outlet were turned upside down (hot top) would be more dangerous. 

It would take a bit for the decorators to adjust...

As far as recessed receptacles, what to do about wall warts?

[ProSoundWeb Community]