C3 Check Air Supply Sensor
electrical
Description
Supply Air Temperature Sensor is out of range; the unit alarms and switches to return air control, or enters Section 4.10.2 if Alarm 00122 is active.
Activation Conditions
Supply Air Temperature Sensor (SAT) is not within the range of -53 to +158°F (-47 to +70° C).
Unit Behavior
Engine and Electric: If Alarm 00122 is not active: functional Parameter Temperature Control is set for Supply Air and the setpoint is in the perishable range: alarm and switch to return air control. If Alarm 00122 is active: alarm and the System will enter Section 4.10.2, refer to Section 1.10.2.
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. Make sure the Configuration Setting (Installed / Not Installed) for SAT2 is correct - Refer to Table 5–1 for Configuration Settings. 2. Check Sensor a. Inspect sensor and connectors. Verify no damage to sensor. Verify no damage, moisture, or corrosion in connectors. b. Check sensor resistance. (Refer to Note 3.) 10,000 Ohms @ 77°F (25°C). Refer to Table 8–3 for chart of resistances for different sensors. 3. Check Sensor Wiring a. Inspect connector pins and terminals at sensor connector. Verify no physical damage to harness. Verify no damage, moisture, or corrosion in connectors. b. Place the system in PC mode, refer to Section 5.3.2 Refer to Note 2 in Notes Section. Disconnect sensor from harness. Check for 3.0 ± 0.1 VDC at harness plug between pins. Voltage should be 3.0 ± 0.1 VDC at harness plug between pins. This verifies microprocessor output and wiring connections to the sensor.