Carrier 69NT40--541--200 TO 299 Operation And Service page 49

High Pressure
P7-0 Switch Closed
(Continued)
High Pressure
P7-1
Switch Open
Perishable Mode
P8-0
Heat Test
Perishable Mode
P8-1
Pull Down Test
Table 3-7 Controller Pre-Trip Test Codes (Sheet 3 of 4)
Note, this test is skipped if the unit does NOT have:
A compressor discharge sensor (CPDS).
A discharge pressure transducer (DPT).
Condenser pressure transducer (CPT).
In addition, this test is skipped if:
The sensed ambient temperature is less than 7_C (45_F).
The return air temperature is less than --17.8_C (0_F).
The water pressure switch (WP) is open, indicating that the unit is operating
with a water-cooled condenser.
Pass/Fail Criteria: Under conditions of the above NOTE; the test immediately
fails if the following inputs are sensed to be invalid:
Compressor discharge sensor (CPDS).
Discharge pressure transducer (DPT).
Condenser pressure transducer (CPT).
OR, if any one of the following inputs are sensed to be invalid:
Return temperature sensor (RTS).
Ambient sensor (AMBS).
In addition, the test will fail if:
The high pressure switch (HPS) fails to open within 15 minutes.
The discharge temperature exceeds 138_C (280_F).
The discharge temperature is less than or equal to ambient temperature
plus 5_C (9_F).
The condenser pressure transducer (CPT) or discharge pressure transduc-
er (DPT) pressure exceeds 27.42 kg/cm
Requirements: Test P7-0 must pass for this test to execute. Setup: The con-
denser fan is started and a 60 second timer is started.
Pass/Fail Criteria: Passes the test if the high pressure switch (HPS) closes
within the 60 second time limit, otherwise, it fails.
Setup: If the container temperature is below 15.6°C (60_F), the set point is
changed to 15.6°C, and a 60 minute timer is started. The left display will read
"P8-0." The control will then heat the container until 15.6°C is reached. If the
container temperature is above 15.6°C at the start of the test, then the test pro-
ceeds immediately to test P8-1 and the left display will change to "P8-1."
Pass/Fail Criteria: The test fails if the 180 minute timer expires before the con-
trol temperature reaches set point. The display will read "P8-0," "FAIL."
Requirements: Control temperature must be at least 15.6°C (60_F).
Setup: The set point is changed to 0°C (32_F), and a 180 minute timer is
started. The left display will read "P8-1," the right display will show the supply air
temperature. The unit will then start to pull down the temperature to the 0°C set
point.
Pass/Fail Criteria: The test passes if the container temperature reaches set
point before the 180 minute timer expires.
(390 psig).
2
3-23
T-317