I would like to use nest to control a "Marine Air Systems Vector" with Mechanical controls. I have an idea using Honeywell relay(s). Please review the wiring diagram attached and provide any feedback. I am trying to replace the MCP in the diagram. The variable speed fan control is unnecessary. RV below is the reversing cylinder. The MCP uses a steel plate thermostat.
Please limit comments to Technical Facts about the electrical circuits and relays.
Thank you in advance.