AAON Fan Proving Switch Upgrade: Ditching Air Switches for Current Sensors

Tired of nuisance fan proving faults on AAON rooftop units? In this video, we ditch the old differential pressure switch technology for good and upgrade to a solid-state current sensor on the VFD output wire. Someone previously butchered this unit by disconnecting the original copper tubing and running improper rubber hose with a deep sag. That sag created a low spot where condensation collected, flooding the pressure switch and taking the unit down. Instead of just replacing another cheap diaphragm switch that will fail again down the road, we show you how to retrofit a Functional Devices RIB current-sensing switch (RIBXGTA-ECM) right at the variable frequency drive. No more pinched tubes, no more condensation traps, and no more false fan failure trips when the VFD ramps down. *What’s Covered in This Video:* The root cause of the breakdown: moisture accumulation in sagging air lines Why mechanical differential pressure switches are outdated on modern VFD systems Selecting and mounting the Functional Devices RIB current sensor Wiring the switch into the AAON control board / safety loop Verifying system operation under full load and low-speed run conditions *Parts & Tools Used:* Functional Devices RIB Current Switch (RIBXGTA-ECM) Wire strippers, crimpers, and standard electrical hand tools Multimeter / clamp meter If you found this technical HVAC walkthrough helpful, make sure to hit *Like**, leave a comment with how you handle failed proving switches in your market, and **Subscribe* for more commercial HVAC diagnostics, upgrades, and field repairs! #HVAC #CommercialHVAC #AAON #VFD #HVACTech #HVACLife #RIBrelay #Fieldpiece #DallasCoolAir