Why four wire instaed of three for range and dryer?

[jap]

I had a customer call me and said they were having trouble with their dryer.
it was 3 wire.
The male corde end was worn out and when they plugged it in the neutral prong of the male cap was not making contact.
when I arrived and went to move pull the dryer out to unplug it and I got between it and a cold water pipe and dang near bit my tongue in half.

 

[kwired]

I had a customer call me and said they were having trouble with their dryer.
it was 3 wire.
The male corde end was worn out and when they plugged it in the neutral prong of the male cap was not making contact.
when I arrived and went to move pull the dryer out to unplug it and I got between it and a cold water pipe and dang near bit my tongue in half.

That voltage - assuming it was not running at the time, was probably coming from the timer motor, or electronic controller. Something had to be trying to draw current to have this voltage present.

 

[jap]

That voltage - assuming it was not running at the time, was probably coming from the timer motor, or electronic controller. Something had to be trying to draw current to have this voltage present.

exactly.

I'm a big fan of the 4 wire system.

 

[ronaldrc]

I think Phillip Hunt the inventer of the three wire plug should take credit for the three wire and four wire
systems.



Click here for his patent application in 1950





Please click the image to open the neutral and see how his patent worked to avoid an electrical shock if the neutral became loose or open

Thanks

 

[RichB]

Yes electricity does take all paths, but in proportion to the resistance of each path. If you were to place a bonding jumper between the stove and sink in your example you do not get that tingle, as there is not enough resistance in the jumper to create enough voltage for you to feel what current is flowing through you. Yes there is some current still flowing through you but is so little you do not feel it, as your body's resistance is much higher than the bonding jumper is.

Should the sink have a fairly solid bond to the electrical grounding system you probably feel nothing either.

Absolutely correct kwired---was just remembering the "fun " of it as a kid when we would grab the oven handle and sink at the same time!!--and this was in a house that was built and wired through the years --like early 1900 to the 30's or so

Merry Christmas all and to all a Happy New Year!!!