Hello all. Just a question about 220V wiring for you. I've encountered
several 3-conductor 220V circuits recently. Doing a little research, I
see that around 1965 or so it was changed to requiring 4-conductor to
seperate the ground and neutral (vs. the old two hots and the third wire
being both the ground and the neutral).

Am I correct in the above? (may only be residential NEC stuff).

The three-wire cable did not "combine" the neutral and ground,
the three wire cable HAD no neutral. 220V has no neutral, it
uses two 110V wires of opposite polarity. The fourth (N) wire
is for modern equipment that also has 110V circutry in it.

Yes, it is both dangerous and forbidden to combine or interconnect
the two.

Is it just me, or do we get this question every day?

--Goedjn