Paul Franklin wrote:
On Tue, 17 Jul 2007 09:33:24 -0700, "** Frank **"
wrote:

I have a clothes dryer with a 120VAC push to start button. In measuring the
terminals, both sides are hot (120V) with respect to ground and zero volts
across the two terminals. Why is that?

I thought there was a short on one side of the push button but the dryer is
working properly. Normally it should be hot only on one side.


Any chance it's a normally closed pushbutton? If you press it when
measuring across it, does the voltage go from zero to 120?

Seems odd that they would use a NC switch, but that's the only thing
that explains what you measure...

Nope; could be N/O with a holding-on contact in parallel; this is a
common arrangement in electromechanical control systems.

--
"Take sides! Always take sides! You may sometimes be wrong - but the man
who refuses to take sides must *always* be wrong! Heaven save us from
poltroons who fear to make a choice!" R.A. Heinlein, "Double Star"