New 220 4 wire stove and old 220 three wire plug

Bob NH said:

Notwithstanding all "The sky will fall on your head" remarks, the National Electrical Code explicitly permits, for existing branch circuit installations, "the frames of electric ranges, wall-mounted ovens, counter-mounted cooking units, clothes dryers, and outlets or junction boxes that are part of the circuit for these appliances" to be grounded to the grounded circuit conductor if all of the conditions that I posted earlier are met.

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Exactly. And the GROUNDED circuit conductor is the neutral. The "ground" is the grounding conductor.
Big, BIG difference.

Speedy Petey said:

Exactly. And the GROUNDED circuit conductor is the neutral. The "ground" is the grounding conductor.
Big, BIG difference.

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Yea what Petey said and the green conductor can not be used here, period

Followup: the old wiring was removed. Good thing too, as it was aluminum. Nice new correct wire run and new recepticle installed. Like my father always told me, "there is only one way to do it...the right way."

thanks for the clarification

Bob NH said:

That (the bolded part of the quote) is just plain WRONG. It will be at a potential equal to the voltage drop in the ungrounded conductor that arises from the IR drop of the unbalanced current, which is the same condition that has existed on ranges, ovens, and dryers for as long as they have had lights and clocks.

With 1 Amp which would be typical of a light, and a 50 ft run to the panel, the potential will be about 0.06 Volt, about 1/25 of the voltage of an alkaline battery. Even if the there were a 100 Amp dead short to the grounded conductor, which would quickly trip the breaker, the voltage would be about 6 Volts which is far below the hazardous level.

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good advice - my search got to this forum because I replaced an oven - both the new and old units had the neutral "white" cable bundled with the grounding "bare copper" cable running about 10 feet to the service box - I had heard that this was out of code and that I should change the wiring to a 4-wire set from the service box - but I had also heard it was a minor, non-critical issue

after reading this, i thought just rewiring it as before would probably be OK - I consulted with an electronics engineer friend who confirmed that, yes, sending an energized neutral into the grounding path is only very slightly risky - he did the math and said we should wire it up, apply power and test the unit with a voltmeter - sure enough, voltage between the oven frame and the kitchen sink is .7 volts

lotus said:

good advice - my search got to this forum because I replaced an oven - both the new and old units had the neutral "white" cable bundled with the grounding "bare copper" cable running about 10 feet to the service box - I had heard that this was out of code and that I should change the wiring to a 4-wire set from the service box - but I had also heard it was a minor, non-critical issue

after reading this, i thought just rewiring it as before would probably be OK - I consulted with an electronics engineer friend who confirmed that, yes, sending an energized neutral into the grounding path is only very slightly risky - he did the math and said we should wire it up, apply power and test the unit with a voltmeter - sure enough, voltage between the oven frame and the kitchen sink is .7 volts

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And how much current or amperage was on this path?

Remember it is not voltage that does harm but amperage that kills!!!!!!

Find yourself a new electronics friend before this one gets you killed.