Carrier 69NT40-541-300, Операция и обслуживание, Страница: 73 / 152

T-318 3 − 41
Table 3-7 Controller Pre-Trip Test Codes (Sheet 6 of 6)
P10 Tests - Frozen Mode Tests:
P10-0 Frozen Mode Setup
Test
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 P10-1.
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.
P10-1
Frozen Mode
Pulldown Test
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
“P10-1” 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, P10-1 will
auto − repeat by starting P10-0 over again.
P10-2
Frozen Mode
Maintain
Temperature Test
Test P10-1 must pass for P10-2 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
P10-2.
During P10-1, the left display will read “P10-2” 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 /
− 1.6 ° C.
Test fails if the average temperature error is greater than +/ − 1.6 ° C, or if the
DataCORDER 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, P10-2 will
auto − repeat by starting P10-0 over again.