Carrier 69NT40-541-001 Operation And Service page 65

CODE # TITLE
P6-5 Not Applicable
P7-0 & P8 are included with the "Auto2 & Auto 3" only. P9-0 through P10 are included with "Auto2" only
High Pressure
P7-0
Switch Closed
High Pressure
P7-1
Switch Open
Table 4–7 Controller Pre-Trip Test Codes (Continued)
Setup: When the unit is running, the condenser fan is de-energized, and
a 15 minute timer is started. The right display shows discharge pressure
if the unit is equipped with a discharge pressure transducer (DPT). If no
DPT is installed, the condenser pressure transducer (CPT) reading will be
displayed.
Pass/Fail Criteria: The test fails if high pressure switch fails to open in 15
minutes.
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 operat-
ing with a water-cooled condenser.
Pass/Fail Criteria: Under conditions of the above NOTE; the test imme-
diately 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 trans-
ducer (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) clos-
es within the 60 second time limit, otherwise, it fails.
DESCRIPTION
Not Used
NOTE
4–29
2
(390 psig).
T-316