"Pete Keillor" wrote in message
...
On Mon, 28 May 2018 21:08:33 -0400, Clare Snyder

wrote:

On Mon, 28 May 2018 17:19:25 -0700, Larry Jaques
wrote:

On Mon, 28 May 2018 11:28:19 -0400, Clare Snyder

wrote:

On Sun, 27 May 2018 22:24:04 -0700, Larry Jaques
wrote:

On Sat, 26 May 2018 19:58:13 -0400, Neon John
wrote:

On Fri, 25 May 2018 11:31:59 -0500, Terry Coombs

wrote:


I think you'll find that those 3 pins are neutral and 220 on
the
other 2 , with either hot to the neutral at 110 .

The 3 conductor 240 volt cable is 2 hots and ground. No neutral
and
thus no 120 volts.
Mine has a 4 wire
socket , with 2 hots a neutral and a ground .

That's what it takes to have a neutral and a safety ground.

I think the NEC demands those only in hospitals. Everyone else
has 2
hots and a not. (safety ground w/ no current)


Required for ranges and driers for at least the last 10 years
here in
Canada - don't know abiout the backwaters of the USA

"Whatever for?" he queried, from said backwater.


So you can use 120 volt lightbulbs and timers and primaries on
control
circuit transformers, and fan motors. and all kinds of other low
power
devices without (illegally) using the safety ground as a neutral,
potentially making the chassis "live" - as has been done,
unofficially, for decades - on both dryers and ranges.

It's a "safety" thing.
They initially allowed the use of the safety ground as a neutral as
a
matter of expediency due to the high price of copper

I got used to having the neutral when I was designing lab carts with
240 V DC motors. It was very handy to have 120 V outlets out in the
middle of the lab for various tasks. My last set of carts were 440V
explosion proof in a classified area, so no outlets on those anyway.

I continued the practice when I built my shop, had the electricians
pull 4 wire for all my 240 V. circuits. But I haven't had the need
since distances are short to plenty of 120 V outlets in the shop.

I will probably relocate nearer the coast in the near future. I may
end up adding 120 V outlets to the welding cart if needed at the new
place.

Pete Keillor

I was only a few feet away from another tech when he tried to measure
an SCR trigger circuit floating on 120V with a grounded scope. When he
flipped the power switch the entire probe exploded from the enormous
current in the braid, sending him to the hospital. I was facing away
and didn't see but I think his body shielded me from the fireball.

-jsw