Check Return Air Sensor

The Return Air Temperature Sensor is out of range, and the unit alarms and switches to supply air control or enters Cargo Protect Mode.

Return Air Temperature Sensor (RAT) is not within range of -53 to +158°F (-47 to +70° C).

Engine and Electric Operation: If alarm 00123 Check Supply Air Sensor is not active: Alarm and switch to supply air control. If alarm 00123 Check Supply Air Sensor is active: Alarm and the System will enter Cargo Protect Mode. Refer to Section 4.10.2.

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.