Check Comp Discharge Sensor
refrigeration
Description
Compressor discharge temperature sensor is out of range -40° to +392°F (-40° to +200°C); the unit gives alarm only.
Activation Conditions
Compressor Discharge Temperature Sensor (CDT) is not within the range of -40° to +392°F (-40° to +200°C).
Unit Behavior
Alarm Only.
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
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. (Refer to Note 3 in Section 7.2) 90,000 Ohms @ 77°F (25°C). Refer to Section 1.9.21 for chart of resistances for different sensors. 2. Check Sensor Wiring a. Inspect connector pins and terminals 2MM. (See wiring schematic Section 1.) Verify there is no physical damage to harness, and no damage, moisture, or corrosion in connectors. b. Place the system in PC mode. Refer to Note 2 in Section 7.2. Disconnect sensor from harness. Check for 3.0 ± 0.1 VDC volts at harness plug between pins. This verifies microprocessor output and wiring connections to the sensor.