WHAT IF… ??? The HPV Goes To 100%, Or The Ambient Increase, Or The Fan On the GC Fails ??? --- Episode-512 Audio

CO2 Rack ‘What-If’ Simulations: Gas Cooler Control, Fan/Motor Issues, and Low-Charge BehaviorBrett Wetzel and Kevin Compass open Episode 511 of the Advanced Refrigeration Podcast discussing busy travel, severe weather, and Brett’s final field training day, where they ran CO2 rack “what-if” simulations. They focus on gas cooler TD control via the gas cooler outlet temperature sensor, stressing proper sensor placement and comparing Danfoss limitations to other EMS options (including saturation-based control and fan lockouts). Brett describes attempts to override sensor values on a pack controller, using offsets instead, and demonstrates how warmer gas cooler outlet temperatures (or fan loss) increase flash gas, driving the BGV and medium-temp suction/compressors. They simulate an I-pressure valve stuck open and discuss pitfalls of overriding valves in multiple Danfoss screens. They troubleshoot inverted/programmable EC fan motors, documentation challenges, daisy-chained control wiring issues, and discuss low-charge behavior causing HPV and BGV to close while cases may starve. They also debate liquid piping pickup location (side vs bottom), heat exchanger effects, superheat settings, and hot gas injection setpoints versus Copeland minimum superheat guidance.