Is this switch compatible with all refrigerants

Zero Minimum Pressure: Operates reliably at 0 PSI inlet pressure

It manages the timed operations of the HVAC cycle

They are the same part

The Johnson Controls P499RAP-101 is a high-accuracy electronic pressure transducer designed for mission-critical HVACR applications

Tekmar Controls 304P Relay Panel 322838-753 Is this switch compatible withThe Tekmar Controls 304P Relay Panel is a professional grade 4 zone switching relay engineered to manage up to four low voltage thermostats and four 120V circulating pumps in hydronic heating applications. Built for technicians who demand reliability in zoned radiant floor or baseboard systems, this hydronic zone control utilizes a microprocessor based design to coordinate calls for heat with precision. The 304P switching relay features RoomResponse