Carrier X4 7700 Operator's Manual page 29

13. Manual Defrost
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1. With the system powered up (START/RUN-OFF switch in the START/
RUN position) press the MANUAL DEFROST key.
2. If the conditions for defrost are met, the status bar and the Box
Temperature display will change to the word "DEFROST". The
MessageCenter will display "DEFROST CYCLE STARTED" for 10
seconds. At the completion of any defrost cycle, the MessageCenter will
return to the default display.
3. If the conditions for defrost are not met, the MessageCenter will display
"CANNOT START DEFROST CYCLE" for five seconds. This message will
be activated when:
• The box temperature is too warm. Defrost may be entered when the
defrost termination temperature sensor (DTT) is below 40°F (4°C)
or the supply air temperature sensor (SAT) is below 45°F (7.2°C)
OR
The engine has not run at least 15 seconds after starting OR
•
The system is in PC mode OR
•
The unit is in Pretrip OR
•
• There is an active shutdown alarm.
START/STOP DIESEL
DEFROST
DEFROST CYCLE STARTED
DEFROST
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SETPOINT F
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