failing to switch as commanded by the thermostat

Plug the signal converter into your digital multimeter set to the DC millivolt scale

The Emerson Alco 065874 Expansion Valve (Model AACE 4 ZW195 5FT 3/8 X 1/2 ODF S/T) is a high-performance thermal expansion valve engineered for R410A air conditioning and refrigeration systems

the AT88A1047 is the manufacturer-specified direct replacement for the 620-758

How do I wire this for 208V versus 240V systems

Carrier S-4004UA Oil Filter Freon failing to switch as commandedThe Carrier S 4004UA Oil Filter is a critical service component designed for high pressure refrigeration and HVAC systems requiring ultra fine filtration. Rated for a 375 PSIG maximum working pressure, this filter is engineered to maintain lubricant chemistry and protect precision internal compressor parts from abrasive contaminants. With a 4 micron filtration rating, it effectively captures microscopic metallic shavings, carbon deposits, and sludge