> On May 27, 2019, at 15:10 , Brandon Ross <br...@pobox.com> wrote:
>
> On Mon, 27 May 2019, Brian Kantor wrote:
>
>> A simple air conditioner thermostat wired to the EPO switch.
>> For safety, wire two thermostats in series so BOTH have to trip
>> before power is shut off.
>
> Admittedly it's been a long time since I worked with basic circuitry, but
> wouldn't wiring them in series cause the circuit to be interrupted if EITHER
> thermostat tripped?
>
An EPO works by shunting a pulled-up line to ground. If you wire them in
series, then the ground has to be shunted to the first segment which is then
fed to the ground side of the second switch which until it is closed will not
shunt the pulled up line to ground.
GND———[contact-closure-1]————[contact-closuer-2]—————EPO
Owen
