I have an application where I need to signal a start by sending a 120V signal to the contactor, so it will close a 208V 3 pole circuit. The load on the circuit will run for an unspecified amount of time, until its work is complete.
At that time, I want the contactor to open again, so that the load will not restart until signal is sent again. I can have no feedback from the load to send a second pulse, and the time may range from 20 minutes to several hours.
The load will cease consuming power on its own at the end of its task, but I want to disable power back to it until I send a signal back to the contactor.
Any ideas? I though of a latching contactor, but that does not work for my application as I can not send an "I am done" signal to disengage the latch.