Zero Minimum Pressure: Operates reliably at 0 PSI inlet pressure

While the electrical contacts are typically SPST (Single Pole Single Throw) and reversible for simple switching

preventing thermal expansion valve (TXV) plugging and protecting new compressor bearings from abrasive debris

They are the same part

ensuring the drive component alignment meets original manufacturer specifications for cooling and ventilation equipment

Tekmar Controls 304P Relay Panel 322838-753 Zero Minimum Pressure: Operates reliablyThe 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