Unusual use of M8/M9 to control a compressor

[ngwagwa]

Couple of caveats -

You don't 'need' to isolate the switch circuit. But doing so does no harm.

You'll be back - I reckon within a couple of weeks - to complain that, whilst under UCCNC control someone switched the compressor on accidentally, and after UCCNC has quit that the compressor has been left operating. That's a more complicated problem!

Doddy - is my circuit in post #5 feasible? If so UCCNC has control so the manual switches have no effect.

Regarding the compressor being left on I already have a signal lamp which comes on when the compressor is powered - this was put in before the 2 way switches as the compressor was often left running! The lamp is visible from our in workshop CCTV camera and we have a networked smart switch so the compressor can be turned off remotely