On 21/06/2011 12:11 PM, Jeffrey Angus wrote:
On 6/20/2011 7:16 PM, William Sommerwerck wrote:
Remember, it ONLY takes ONE switch to OPEN a series circuit.
That is ALL that is required to control whether or not the
element gets hot or cools off.

You were not paying attention! Any heating device that uses both "phases"
requres TWO switches to open it.


Oh, and by the way, since you brought it up, the bit about
both of the 240 volt sources being "hot with respect to
neutral". The heating elements are connected ACROSS the 240
VAC source, NOT split with each half going from the two
sources to neutral. (That would require a double contact to
turn each PAIR of heating elements on and off.)

I'm not sure what you're talking about. First, there is no "240V"
source in
my condo. There are multiple 120V sources from which you can get higher
voltages by spanning them. (I assume each voltage is referenced to some
"neutral" point.) In my preceding apartment, I took advantage of this to
build a break-out box -- all to code, I have several electrician
friends who
advised me -- to provide individual lines for my class A power amps.

As someone else kindly pointed out, this oven has one side of its
elements
hard-wired to AC. Bad, bad, bad, bad idea.

Damn you are ****ing dense William.

The heating element from one hot lead to the other hot lead.
At NO time is there a connection to Neutral. Hence it ONLY
requires a SINGLE pole switch to open a SERIES circuit.

I see no inconsistency. A correctly functioning heating element can be
turned off, in the sense of no longer heating, by means of a single pole
switch.

But what about a non-correctly functioning heating element? One, for
example, that's shorted to its grounded covering somewhere along its
length. This could result in part of the element overheating, and an
owner noticing this would likely respond by turning the appliance off at
its switch. In the case of a heating element that spans two 110 v lines
in opposite phase, turning it off by a single pole switch won't have the
desired effect. Better hope that an earth leakage detector is fitted in
the supply lines, and works.

Sylvia.