Tjernlund Products PS1503 Switch R-407A the static overload pressure should

the static overload pressure should not exceed 60 bar to avoid zero-point shifts

making it suitable for both pilot duty and direct control

making it a staple for technicians servicing large-tonnage Trane air handlers and rooftop units where precise refrigerant flow control is non-negotiable

quick-tight connection to compressor terminals

Tjernlund Products PS1503 Switch R-407A the static overload pressure shouldThe Tjernlund Products PS1503 is a high sensitivity duct pressure switch engineered to automate HVAC accessories by detecting positive air pressure within the supply plenum or trunk lines. As the direct replacement for DFS 221 227, this SPST normally open switch simplifies field installations by eliminating the need for complex interlock wiring with the furnace blower. The PS1503 duct airstat features a snap acting mechanism triggered by a precise