P9-0 DTT Closed and Open Test
During P9-0 the defrost temperature sensor (DTS) reading will be
displayed on the left display. The right display will show the supply air
temperature.
The unit will run FULL COOL for 30 minutes maximum until the DTT is
considered closed. This step may not have to be executed. Once the DTT
is considered closed, the unit simulates defrost by running the heaters for
up to two hours, or until the DTT is considered open.
Test fails if:
The DTT is not considered closed after the 30 minutes of full
cooling.
HTT opens when DTT is considered closed or if return air tem
-
perature rises above 48°C (120°F).
Test passes if the DTT is considered open within the 2 hour heat cycle
time limit.
P10 Tests - Frozen Mode Tests:
P10-0 Frozen Mode Heat 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
10-1. During this test, the control temperature will be shown on the right
display.
The 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 setpoint,
the test proceeds to test 10-1.
P10-1 Frozen Mode Pulldown Test Control temperature must be at least 7.2°C (45°F)
The setpoint is changed to -17.8°C. The system will then attempt to pull
down the control temperature to setpoint using normal frozen mode
cooling. During this test, the control temperature will be shown on the right
display.
The test passes if the control temperature reaches setpoint minus 0.3°C
before the 180 minute timer expires. Otherwise, the test fails. Upon failure
and when initiated by an automatic pre-trip sequence, P10-1 will auto-
repeat once by starting P10-0 over again.
P10-2 Frozen Mode Maintain
Temperature Test
Test P10-1 must pass for this test to execute.
Same as for test 8-2 except the control temperature is the return probe
temperature.
The average error must be +/-1.6°C. If the DataCORDER supply
temperature probe is invalid, the test fails and the control probe
temperature will be recorded as -50°C. Upon failure and when initiated by
an automatic pre-trip sequence, P10-2 will auto-repeat by starting P10-0
over again.
Table 4–9 Controller Pre-Trip Test Codes (Continued)
