The 3R1C0 probe works on the principle of liquid conductivity

8 RLA rating and 60 Hz frequency

it is specifically optimized for R-22 service in existing systems as well as R-407C applications

reducing the frequency of probe cleaning and maintenance

Carrier HT680056 Transformer R-407C The 3R1C0 probe works onWhen you're out in the field and find a secondary side with no voltage, the Carrier HT680056 Transformer is the reliable OEM replacement part you need to restore the 24V control circuit. Built specifically for Carrier, Bryant, and Payne equipment, this 40VA HVAC transformer handles the step down from a 120V primary to a steady 24VAC secondary output. It is a critical component for powering furnace control boards, ignition modules, and 24V thermostats.