measure the resistance of the compressor thermstors (should be below the trip point resistance) and verify that the module is receiving the correct 120/240V supply voltage across the power terminals

Can I install this myself

What is the purpose of the 4-8"wc spring range

the DFS-221 series generally supports differential sensing

Robertshaw 5000-071 Thermostat THPU32HP7Y measure the resistance of theThe Robertshaw 5000 071 is a high capacity, heavy duty commercial electric thermostat designed for demanding process control applications where precision is paramount. This 5000 Series (D1 style) control features a Double Pole Single Throw (DPST) snap action mechanism with a positive "OFF" position, making it an essential component for high amperage systems. Rated for 30 Amps at 120 277V AC and up to 10 Amps at 480V AC, it provides reliable switching