Carrier 69NT40-541-505 Operation And Service Manual page 76

P10 Tests - Frozen Mode Tests:
Frozen Mode Setup
P10-0
Test
Frozen Mode
P10-1
Pulldown Test
Frozen Mode
P10-2 Maintain
Temperature Test
T-368
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Table 4–7 Controller Pre-Trip Test Codes
After completion of the Defrost Test, if the container temperature is below 7.2C,
the setpoint is changed to 7.2C, and a 180 minute timer is started. The control will
then be placed in the equivalent of normal heating.
If the container temperature is above 7.2C at the start of the test, then the test
proceeds immediately to test P101.
During P10, the control temperature will be shown on the right display.
Test fails if the 180 minute timer expires before the control temperature reaches
setpoint - 0.3C. If the test fails, it will not auto-repeat.
There is no pass display for this test. Once the control temperature reaches set
point, the test proceeds to test 10-1.
When the container temperature is greater than or equal to the 7.2C (45F) set
point which was set in the frozen mode heat test, the left display will read P101
and the right display will show the return air temperature. The set point will then be
changed to 17.7C (0F). The unit will then have a maximum of three hours to pull
the container temperature down to the 17.7C set point.
If this occurs within the three hour time limit, the test passes. If pulldown is not
completed within the three hour time, the test fails.
Upon failure and when initiated by an automatic Pretrip sequence, P101 will auto-
repeat by starting P100 over again.
Test P101 must pass for P102 to execute.
A fifteen minute timer is started, and the system will attempt to minimize control
temperature error (return temperature minus setpoint) until the timer expires. The
control temperature will be sampled each minute starting at the beginning of P102.
During P101, the left display will read P102 and the right display will show return
air temperature.
When the test is completed, the average control temperature error will be com
pared to the pass/fail criteria.
Test passes if the average temperature error is within +/-1.6C.
Test fails if the average temperature error is greater than +/-1.6C, or if the Data-
CORDER supply temperature probe is invalid. If the test fails, the control probe
temperature will be recorded as -50.0C.
Upon failure and when initiated by an automatic Pretrip sequence, P102 will auto-
repeat by starting P100 over again.
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