4–1
T-374
SECTION 4
TROUBLESHOOTING
4.1 Alarms
Alarm display is an independent controller software function. If an operating parameter is outside of the expected
range or a component does not return a valid signal back to the controller, an alarm is generated. The
EverFRESH
TM
Controlled Atmosphere option alarms are AL907, AL909, AL910, AL929, AL962, AL976, AL977,
AL978, AL979, AL980, and AL981. For units configured with the CO
2
injection option, additional alarms AL982 and
AL983 are available.
AL907
Manual Fresh Air Vent Open
Cause:
For units equipped with EverFRESH and a Vent Position Sensor (VPS), the controller will monitor
the manual fresh air opening at a pre-determined time. If during this time the manual fresh air vent
is open and EverFRESH is active, an alarm will be generated. If alarm is active, the controller
monitors the manual fresh air once per hour. Upon clearing the alarm, the controller goes back to
monitoring at the pre-determined time.
Component
Vent Position Sensor (VPS)
Troubleshooting
Manually reposition the vent to 0% and confirm using Cd45. If Cd45 is not
reading 0%, perform a calibration of the panel.
If a zero reading cannot be obtained, replace the defective VPS.
If the unit is loaded, ensure the vent is closed. Note and replace the VPS
on the next PTI. The alarm will not affect the EverFRESH system from
operating.
AL909
O2 Sensor Fault
Cause:
Triggered anytime the O
2
sensor reading is outside of the normal operation range, after an initial
signal was detected.
Action:
Control CO
2
by running the EverFRESH Air Compressor (EAC) and opening the EverFRESH Air
Valve (EA). Controlling CO
2
via the EA will also prevent low O
2
and cargo loss. If both AL909 and
AL910 are active, run the EAC and open the EA.
Component
O
2
Sensor, O
2
Amplifier
Troubleshooting
Check Cd44 and scroll down to 02V. The O
2
sensor output will be
displayed in millivolts (130mV to 4100mV is good range).
Check wiring (refer to schematic), and check for bad connections or wires
positioned improperly.
If the O
2
sensor is available, remove the upper fresh air panel and
evaporator motor and replace the sensor. If after replacing the sensor
Cd44 reads outside of the normal range and AL909 continues, replace the
amplifier.
If parts are not available, turn the EverFRESH option off via Cd71 and open
the manual fresh air vent.
Summary of Contents for EverFRESH
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Page 56: ...T 374 5 26 4 Note the orientation of the check valve 5 Reinstall in reverse order ...
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Page 67: ...8 1 T 374 SECTION 8 SCHEMATICS DIAGRAMS STANDARD UNITS Figure 8 1 Legend Standard Units ...
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Page 70: ...T 374 8 4 Figure 8 4 Wiring Diagram Standard Units ...
Page 72: ...T 374 9 2 Figure 9 2 Schematic Units with CO2 Injection Page 1 ...
Page 73: ...9 3 T 374 Figure 9 3 Schematic Units with CO2 Injection Page 2 ...
Page 74: ...T 374 9 4 Figure 9 4 Wiring Diagram Units with CO2 Injection ...
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