Carrier 69NT40-541-001 Operation And Service page 64

CODE # TITLE
P5-0 Supply/Return Probe Test
P5-1 Supply Probe Test
P5-2 Return Probe Test
P-6
P6-0 Compressor On
P6-H & P6L
Suction Modulation Valve
P6-2
(Open and Closed)
P6-3 Quench Valve Test
P6-4 Not Applicable
T-316
Table 4–7 Controller Pre-Trip Test Codes (Continued)
Setup: The High Speed Evaporator Fan is turned on and run for eight
minutes, with all other outputs de-energized.
Pass/Fail Criteria: A temperature comparison is made between the re-
turn and supply probes.
If this test fails, "P5-0" and "FAIL" will be displayed. If both Probe tests (this
test and the PRIMARY/ SECONDARY) pass, the display will read "P5"
"PASS."
Requirements: For units equipped with secondary supply probe only.
Pass/Fail Criteria: The temperature difference between primary and sec-
ondary probe (supply) is compared.
If this test fails, "P5-1" and FAIL will be displayed. If both Probe
tests (this and the SUPPLY/ RETURN TEST) pass, because of
the multiple tests, the display will read 'P 5' 'PASS'.
Requirements: For units equipped with secondary return probe only.
Pass/Fail Criteria: The temperature difference between primary and sec-
ondary probe (return) is compared.
1. If this test fails, "P5-2" and "FAIL" will be displayed. If both Probe
tests (this test and the SUPPLY/ RETURN) pass, because of the
multiple tests, the display will read "P 5," "PASS."
2. The results of Pre-Trip tests 5-0, 5-1, and 5-2 will be used to acti-
vate or clear control probe alarms.
Setup: A current draw test is performed before the compressor is started.
The compressor is started. SMV is opened and another current draw test
is per formed.
Pass/Fail Criteria: Passes if the change in compressor current draw is
within the specified range.
Setup: The compressor and fans continue to run from the previous test.
The quench valve (if configured) will operate as in normal control mode.
The SMV is closed to 0% open, current and condenser pressure readings
are taken. The SMV is opened to 50% with continuous current and con-
denser pressure readings taken to establish maximum values. The SMV
is returned to 0% open and final readings are taken.
Pass/Fail Criteria: Passes if the calculated difference in current at the
50% open position are above a specified value before and after opening
of the SMV, OR the calculated difference in condenser pressure at the
50% open position are above a specified value before and after opening
of the SMV
Setup: The compressor suction temperature is measured with the
Quench valve closed. The Quench valve is energized and the suction
temperature drop is checked.
Pass/Fail Criteria: Passes if suction temperature is within the valid range.
DESCRIPTION
NOTE
NOTES
Not Applicable
Not Applicable
Not Used
4–28