Wiring On/Off switch for 220v 5hp Compressor

[matt_i]

A disconnect could easily interrupt the control voltage. Bring over a neutral wire to the enclosure where this sits, then the proposed wall switch, pressure switch and coil will be either hot wire to neutral. Or, get a 50VA control transformer and skip the neutral.

 

[alfredeneuman]

Not so. Controls are fed separately on equipment all the time. If the OP does it that way there should be a label stating something like "CAUTION. Some circuits on this equipment are energized even when the main power is disconnected".

Tommy

I misspoke.
If the disconnect doesn't de-energize the control circuit, in addition to the signage, you have to install an additional disconnect immediately adjacent to the main disconnect just to serve the control circuit.
It would be much easier to just use a 240 Volt coil in the contactor, and have a single disconnecting means.