Reversed polarity receptacles

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Re: Reversed polarity receptacles

Roger, seems we have a mixup on terminology. I think of the shell as the outer portion of the socket. You must be referring to the portion of the socket which accepts the threaded base of the bulb. There is no great danger in connecting this part of the socket to the hot conductor. It has been done for decades. Provided of course that the insulation is still intact.
 
Re: Reversed polarity receptacles

Polarity has more than one meaning.I don't think they have to be implying the direction of the voltage.

Since one meaning is pointing toward the configuration of the plug could be correct.

Ronald :)
 
Re: Reversed polarity receptacles

Hello Ronald, hope all is well.

Rattus,
You must be referring to the portion of the socket which accepts the threaded base of the bulb.
you are correct, and the reason I refer to it this way is because the NEC calls it a "screw shell" and requires the "grounded conductor" (if part of the circuit to the lamp holder) be connected to it.

As far as danger is concerned, we know that polarization didn't matter for years, but obviously at some point in time, some one or ones in the code making and electrical manufacturing processes decided there was potential danger that could be reduced by polarizing.


We know using the word polarization in this context is not true polarization as far as the purist is concerned when talking about electrical theory.

Roger
 
Re: Reversed polarity receptacles

Roger, now we are talking. I can see a problem if the paper insulation fails and the screw shell is hot. And, in the old days some radios worked better when you reversed the plug in the receptacle. Without going into detail though, it just seems right that you should maintain the polarity into any kind of plug-in appliance.
 
Re: Reversed polarity receptacles

Of course proper "polarity" of the wiring is important & NEC requires it.

NEC does not tell you why it is important, because that is not the purpose of the NEC.

Those of you old enough or "used" enough, may recall the days of 2-slot receptacles, no polarity standards, 2-wire cords on metal-frame drill motors & radios, the virtual non-existence of equipment grounding (bonding), etc.,etc.
It was not too uncommon to hear of someone being electrocuted. It was a bad deal. As an electrical professional, sometimes I feel maybe a little embarrased that it took "us" so many years to right some of these wrongs.
 
Re: Reversed polarity receptacles

"I'm fine Roger thanks for asking"

Right on kilo-amp.

Like you are saying as an As an electrical professional and working hands on every day with these devices like a keyless light fixture or also known as a rosette which has a metal shell very accessible to holding when screwing in a bulb know how dangerous it can be if not polarized.Has nothing to do with the insulation breaking down its just down right accessible.
 
Re: Reversed polarity receptacles

Kiloamp, I would argue that it is the addition of the EGC which made those power tools safer. It was usually an insulation failure which caused the problem, and that could occur within the windings or in either or both conductors. A simple two-wire polarizing plug would not solve the problem.

Ronald, think of a lamp socket with a metal housing. A piece of cardboard insulates it from the screw shell. That is what I am talking about. Not sure what you mean by a rosette. I am unaware of any lamp socket which exposes one to either hot or neutral when changing bulbs. Educate me.
 
Re: Reversed polarity receptacles

Rattus

I think you are putting us on the standard light fixture used in your regular unfinished basement the porcelain type.Check them out if you are not familiar with them.There is no way you can start screwing a bulb in one without having the whole shell of the bulb exposed if it is made hot watch out. :)

[ April 06, 2005, 11:00 PM: Message edited by: ronaldrc ]
 
Re: Reversed polarity receptacles

Ronald,

Now we are talking, but some part must be missing for the screw shell to be exposed. A threaded porcelain ring is used to hold these things together. Sometimes that ring is broken or lost, then we have the scenario you describe.

Rattus
 
Re: Reversed polarity receptacles

Lady, in my opinion reversed polarity does not present much of a shock hazard because the grounded conductor (neutral to some) should not be connected to the chassis of any plugin device.

However, for those appliances with switches, it is desirable to switch the hot line. Perhaps someone can give us an example of RFI suppression or surge suppression where polarity makes a difference.

Rattus
 
Re: Reversed polarity receptacles

Ratus,
The problem with the ungrounded conductor connected to to the socket screw shell is when you are relamping. It would be very easy to be touching the male threads on the lamp as you insert it in the socket. If the socket is reverse wired, you are now connected to the ungrounded conductor.
Don
 
Re: Reversed polarity receptacles

Don, that is a possibility, but I always hold the bulb by the opposite end. That is why I say there is no great shock hazard. I have been nipped a few times though by getting my finger across the prongs of an AC plug especially when removing a tight one.

No argument though,proper polarity should be maintained.
 
Re: Reversed polarity receptacles

Thanks Lady Spark, Just as Don said a fault has nothing to do with it as far as the bulb.

But back wards polarity that is a grounded neutral and hot reversed is always a possible shock hazard. To answer your question yes you would be shocked "but" if the fault was the neutral touching something that should be at ground potential and is hot because of reverse polarity it would probably kick the breaker and also shock you maybe a little less but don't count on it.

Ronald :)

[ April 07, 2005, 02:20 PM: Message edited by: ronaldrc ]
 
Re: Reversed polarity receptacles

lsl: not all plug in devices are double insulated. The NEC is a safety code and these items are not just window dressing standards. Reversing polarity of receptacles and wired devices is more than a slight hazard. It has also been required to do so for so long that others are used to that scheme and count on it, even though they shouldn't.

yes, there exists a shock hazard and the specifics would determine the extent. Remember, some people are very sensitive to electrical current, being more conductive, weaker heart, whatever, and could easily die from what some might consider a minor shock.

paul :cool:
 
Re: Reversed polarity receptacles

Paul,

Agreed, one should maintain proper polarity, but to my knowledge a hot neutral in itself is not a shock hazard except for the case of a lamp base which may be exposed even with the lamp fully seated. Of course, that is too much.

Rattus
 
Re: Reversed polarity receptacles

I agree that most electrical items are for the most part insulated very good and not a shock hazard.

But I have always been taught safety and to enforce it very strongly.

And like Rattus is saying we need to try to maintain the correct polarity.

Rattus you miss quoted we don't have a hot neutral we have reversed polarity at the outlet if we tried to make the neutral hot it would kick a breaker. :)
 
Re: Reversed polarity receptacles

Ronald,

You know that I mean the slot that ought to be the neutral is hot and vice versa.

Rattus
 
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