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[Scott Smith]

Rick Stansby wrote on Mon, 13 December 2010 13:12

Jay Barracato wrote on Mon, 13 December 2010 04:33 The logic that was explained to me the first time I saw a contractor doing that was that if a paper clip or something was dropped on a partially inserted plug, it would hit the ground first and slide off, instead of potentially shorting the hot/neutral. "upside down" edison plugs used to be a pet peeve of mine, but then someone explained what you have just explained, and now I prefer them "upside down".

"Falling paper clips"....

[Jeff Wheeler]

John Roberts  {JR} wrote on Mon, 13 December 2010 13:17

OTOH during a flood the rising water would hit a ground lug down terminal first and harmlessly ground the water... While I concede this is a slender benefit.

Who knows what a rising flood might hit first.  It could be a conductor supplying the receptacle, and which one that might be is anybody's guess.

I have read some lively debate on the topic of which way to install receptacles.  I remain convinced that either way is okay, but I have a few appliances in my home that have angle cords which like to be plugged in "right side up."  I have never seen an angle cord meant for "upside down" operation.  Polarized wall warts support themselves against the faceplate, box, or wall best if they are plugged in "right side up."  If I was deciding which way to mount them myself, I would go with "ground down."  If I hired an electrician to do work for me and he put my receptacles in "ground up" I would not throw a fit.

[Milt Hathaway]

Jeff Wheeler wrote on Mon, 13 December 2010 13:53

John Roberts  {JR} wrote on Mon, 13 December 2010 13:17 OTOH during a flood the rising water would hit a ground lug down terminal first and harmlessly ground the water... While I concede this is a slender benefit. Who knows what a rising flood might hit first.  It could be a conductor supplying the receptacle, and which one that might be is anybody's guess.

Of course, at a certain point it doesn't matter:

[dave tesch]

when my home flooded with 9' of water the power stayed ON. the service panel (completely submerged) stayed ON. full power to entire house; in fact we powered the trash pump from house power to suck the water out. water is a lousy conductor of electricity, it almost doesnt conduct at all but the impurities in water do. apparently the water that flooded my home was clean enough that it did not conduct electricity even when submerging the service panel and entrance.

as per the "upside down" edisons, the ones mounted with ground pin DOWN are upside down. look at most other plugs/outlets in the code and they are ground pin UP.

[Bennett Prescott]

Wow. A picture is worth a thousand words.

[Greg Cameron]

dave tesch wrote on Mon, 13 December 2010 12:22

water is a lousy conductor of electricity, it almost doesnt conduct at all but the impurities in water do. apparently the water that flooded my home was clean enough that it did not conduct electricity even when submerging the service panel and entrance.

Sure, but who's going to stick their arm in to find out? lol... All it takes is one container of Morton's salt in the cupboard to get into the mix to create a lethal electrolyte. Back in EE school in college, I recall a lab where we tested conductivity of distilled water, vs. tap water, vs. either with a tiny pinch of salt. Average tap water was indeed a poor conductor of 120v house voltage though it did conduct somewhat. However, just a few grains of salt in a beaker was enough to turn it into a very good conductor. I certainly wouldn't want to chance a submerged building with known live juice in it. That open bottle of catchup you left on the coffee table eating In-N-Out french fries could be your undoing

Greg

[Gus Housen]

Isnt a metal gang box gounded anyway so water would touch the grounded box anyway?

[Randy Gartner]

dave tesch wrote on Mon, 13 December 2010 20:22

when my home flooded with 9' of water the power stayed ON. the service panel (completely submerged) stayed ON.

If the breakers never tripped while the panel was fully submerged,it was probably a Zinsco or FPE.That's why they went out of bussiness.As far as ground up or down,it was never addressed in the NEC to my knowledge.As far as a metal cover falling off,I only have ever seen that once in 36 years as an electrician.In that case,the ground was up but it still shorted because it touched both the ground and the hot prong of the cord.

[Jay Barracato]

Randy Gartner wrote on Mon, 13 December 2010 21:41

dave tesch wrote on Mon, 13 December 2010 20:22 when my home flooded with 9' of water the power stayed ON. the service panel (completely submerged) stayed ON. If the breakers never tripped while the panel was fully submerged,it was probably a Zinsco or FPE.That's why they went out of bussiness.As far as ground up or down,it was never addressed in the NEC to my knowledge.As far as a metal cover falling off,I only have ever seen that once in 36 years as an electrician.In that case,the ground was up but it still shorted because it touched both the ground and the hot prong of the cord.

Or more likely the power was off further upstream before the panel was submerged.

edit- I just remembered being extremely frightened at Del Fest after the storm a couple years ago with a foot of standing water everywhere around the stage and no clue where the power lines were.

[Clayton Luckie]

Milt Hathaway wrote on Mon, 13 December 2010 14:11

Of course, at a certain point it doesn't matter:

That's not what I meant when I asked for "shore power".  

cl