62-11640 7–52
00122 CHECK RETURN AIR SENSOR
• ACTIVATION: Return Air Temperature Sensor (RAT) is not within the range of -53 to +158°F (-47 to +70°
C).
• UNIT CONTROL: Engine and Electric Operation:
If Alarm 00123 is not active: Alarm and switch to supply air control.
If Alarm 00123 is active: Alarm and the System will enter Cargo Protect Mode. Refer to Section
4.11.2.
• RESET CONDITION: Auto reset when sensor is in range or, alarm may be manually reset using the dis-
play mounted keys or by turning the unit off, then back on again.
NOTE: Follow the steps below until a problem is found. Once a repair or correction has been made, the active
alarm should clear itself (refer to reset condition above). Operate the unit through the appropriate modes to see
if any active alarm occurs. Continue with the steps below as necessary.
1. Check Sensor
a. Inspect sensor & connectors. Verify there is no damage to sensor, and no damage, moisture, or
corrosion in connectors.
b. Check sensor resistance. (Refer to Note 3 in Notes Section, page 7-2.) 10,000 Ohms @ 77°F
(25°C). Refer to Table 8–3 for chart of resistances for different sensors.
2. Check Sensor Wiring
a. Inspect connector pins & terminals at sensor connector 2MM. (See wiring schematic
Section 10.3
)
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 Notes Section, page 7-2. Disconnect sensor
from harness. Check for 3.0 ± 0.1 VDC at harness plug between pins. Voltage should be 3.0 ± 0.1
VDC volts at harness plug between pins. This verifies microprocessor.
00123 CHECK SUPPLY AIR SENSOR
• ACTIVATION: Supply Air Temperature Sensor (SAT) is not within range of -53 to +158°F (-47 to +70° C).
• UNIT CONTROL: Engine and Electric Operation:
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 Cargo Protect Mode. Refer to Section
4.11.2.
• RESET CONDITION: Auto reset when sensor is in range or, alarm may be manually reset using the dis-
play mounted keys or by turning the unit off and then back on again.
NOTE: Follow the steps below until a problem is found. Once a repair or correction has been made, the active
alarm should clear itself (refer to reset condition above). Operate the unit through the appropriate modes to see
if any active alarm occurs. Continue with the steps below as necessary.
CORRECTIVE ACTIONS:
1. Check Sensor
a. Inspect sensor & connectors. Verify there is no damage to sensor, and no damage, moisture, or
corrosion in connectors.
b. Check sensor resistance. (Refer to Note 3 in Notes Section, page 7-2.) 10,000 Ohms @ 77°F
(25°C). Refer to Table 8–3 for chart of resistances for different sensors.
2. Check Sensor Wiring
a. Inspect connector pins & terminals at sensor connector 2MM. (See wiring schematic
Section 10.3
)
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 Notes Section, page 7-2. Disconnect sensor
from harness. Check for 3.0 ± 0.1 VDC volts at harness plug between pins. This verifies micropro-
cessor output and wiring connections to the sensor.
To Next Page
Loading...
Need help?
General
