Non Grounded duplex poll. Which is safer?

[tryinghard]

Earl W. Roberts (PE & author of Overcurrents and Undercurrents) sure has some strong passion about GFCI?s. He states on Page 56 of his book

?For many years, and even now to some extent, the GFCI has been considered as only a backup to ?good grounding.? I cannot stress enough the GFCI protection is far superior to grounding as a means of protecting people from electric shock? and ?It?s time for someone to speak up and set the record straight! The GFCI is more than TWICE as effective as equipment grounding in preventing fatal electric shocks from ground faults.?

I think he was referring to an article he previously wrote in 82 here.

 

[tryinghard]

If an appliance or tool has a fault I would prefer a GFCI over equipment grounding alone because it opens the circuit at 5mA compared to a full 16 or 21A. A 2 wire circuit usually doesn?t include an effective ground fault path making it dangerous, and they didn?t wire the old places like we do in an out of outlet boxes, because of this I think the GFCI breaker is best but may not be available for the old panels or fuse boxes still in use - this also keeps the neutral bonding honest.

 

[ptonsparky]

I do not believe the gfci device will protect you from shock when installed on a two wire circuit. It may prevent death. If the current is limited to 4ma would you rather touch the grounded conductor of a properly operating 2 wire circuit or grab the end of an open neutral?

 

[tryinghard]

I do not believe the gfci device will protect you from shock when installed on a two wire circuit. It may prevent death. If the current is limited to 4ma would you rather touch the grounded conductor of a properly operating 2 wire circuit or grab the end of an open neutral?

Will the regular users be doing this, or are you asking about an electrician?

 

[480sparky]

I do not believe the gfci device will protect you from shock when installed on a two wire circuit. It may prevent death. If the current is limited to 4ma would you rather touch the grounded conductor of a properly operating 2 wire circuit or grab the end of an open neutral?

GFCI do not (nor cannot) limit current. If your body will create a 150 ma current flow, then 150 ma of current WILL flow.

So touching either one would make no difference. The GFCI will only limit the time you get zapped.

 

[ptonsparky]

I did not say the GFCI would limit the current to 4ma, it is limited by the circuit impedance. For this purpose the GFCI will not trip under 5ma.