Ground/Neutral Receptacle Connections

[jaggedben]

No, except for possibly the switch, the polarity of the cord is not because the narrow prong is in any way connected to a "more insulated" wire than the other.

I didn't say it was, in that last post. In fact I never mentioned insulation. And the question remains to me, what is the point of the polarized plug on these tools?

 

[Jamesco]

So I had in mind power tools, not lamps. For example, my circular saw, palm sander, router, an rotohammer all have polarized 2-prong plugs. I suppose there's probably something to the design that makes one internal lead more worth being protected from than the other. Maybe the switch.

For all the tools you listed above the hot conductor is connected to the power switch. Like LarryFine said the double insulated power wiring is the same.

In the case of 2 wire cord and plug connected electronic equipment, the hot conductor of the cord is connected to the fuse, or circuit breaker, and then to the power switch.

 

[LarryFine]

And the question remains to me, what is the point of the polarized plug on these tools?

Probably a combination of tradition and UL listing requirements.

 

[JFletcher]

Very good point on the shock hazard, but wouldn't a break in the neutral just result in an open circuit regardless of there being no EGC?

Worst case problem there is a fault in the equipment that is not high enough to trip the breaker or fuse. The equipment will sit at a hundred and twenty volts and light you up like a Christmas tree when you touch it and another conductive object that is at a lower potential. The other object does not have to be grounded in a classical sense.

I learn this fact one day in July many years ago when I put my sweaty hand on the handle of my plug-in air compressor, went to pull it, it wouldn't budge, so I put my other hand on the tongue of my Jet Ski trailer for leverage. 120v hurts if your resistance is low like mine was. The Jet Ski trailer was sitting on a concrete slab with about one square inch of metal making contact. There was no ufer, no CEE, in the slab