(ET) contactor

[Neil Dennis <wombatt gmail com>]

From the description, that contactor is the same as a double pole 
single throw switch.  The two top studs would be common, when it is 
closed (actuated by 24 volts across the little studs) the switches close 
and feed power somewhere. 

You really will have to study the circuit,  there is a possibility the 
top studs should not be connected but slim.

Did you say that is a Ryobi ?  I suppose I could take a look at the one 
I have and see what 's there.

wombat