07009@vector-8500medium
Return Air Sensor Out of Range (RAT and RAT2)
electrical
Description
RAT2 differs from RAT by 2°C for 10 consecutive one minute samples or 25 of the last 30 samples, and if RAT2 is active the unit switches to RAT.
Activation Conditions
A Redundant Return Air Temperature Sensor (RAT2) is installed, configured, and it differs from RAT by 2°C for 10 consecutive one minute samples or for 25 of the last 30 samples.
Unit Behavior
Engine and Electric Operation: If RAT2 is selected as the active probe, switch active probe to RAT probe.
Reset Conditions
Auto reset when sensor is in range or, alarm may be manually reset using the display mounted keys or by turning the unit off, then back on again.
Corrective Actions
Refer to the manual troubleshooting procedure.