Check Evaporator Temperature Sensor
refrigeration
Description
Evaporator Surface Temperature Sensor is out of range; the unit gives an alarm only in Engine and Shore Power operation.
Activation Conditions
Evaporator Surface Temperature Sensor (EST) is not withing range of -53° +158°F (-47° to + 70°C).
Unit Behavior
Engine Operation Shore Power Operation (Alarm only)
Reset Conditions
Auto reset when sensor is in range or alarm may be manually reset from the AI, Cabin Tech, or by turning the unit off and then back on again.
Corrective Actions
1. Check Sensor a. Inspect sensor and connector. Verify there is no damage to sensor, and no damage, moisture, or corrosion in connector. b. Check sensor resistance. 10,000 Ohms @ 77°F (25°C). Refer to Table 8–3 for chart of sensor resistances. 2. Check Sensor Wiring a. Inspect connector pins and terminals at CCU J2-3 and J2-12. Verify there is no physical damage to harness, and no damage, moisture, or corrosion in connectors. b. Disconnect sensor from harness (Unit Powered ON). Check for 3.0 ± 0.1 VDC volts at harness plug between pins. This verifies microprocessor output and wiring connections to sensor.