Carrier PrimeLINE 69NT40-561-200 Operation And Service Manual page 92

P6-5 Compressor Leak Test
P6-6 through P6-10 are conducted by changing status of each valve and comparing suction pressure
change and/or compressor current change with predetermined values. Tests will cause compressor and
condenser fans to cycle on and off as needed to generate the pressure required for individual pre-trip
sub tests. The compressor will start in order to build discharge pressure, followed by compressor pump
down sequence. At the conclusion of compressor pump down sequence, the compressor will shut down
P6-6 Economizer Valve Test
P6-7 Digital Unloader Valve Test Passes if pressure and current changes are within 3 seconds of DUV
P6-9 Liquid Injection Valve Test (If equipped) Test passes if change of suction pressure is greater than
P6-10 Electronic Expansion Valve
Test
P7-0 & P8 are included with "Auto 2 & Auto 3" only. P9-0 through P10 are included with "Auto2" only.
P7 Tests - High Pressure Tests: Unit is run at full capacity without condenser fan running to make sure
P7-0 High Pressure
(HPS) Opening Test
P7-1 High Pressure
(HPS) Closing Test
T-362
Table 4–7 Controller Pre-Trip Test Codes (Continued)
Pre-trip P6-5 ensures that the compressor holds pressure. After com-
pressor pump up and pump down, the compressor is turned off for 62
seconds. When suction side pressure holds (less than 8 psi rise) for 10
seconds, P6-5 passes, otherwise the Compressor Leak Test fails.
Refer to the
technician in troubleshooting a P6-5 occurrence.
and the valve test will start.
Passes if suction pressure increases a minimum of 4 psia when the
valve opens for 15 seconds.
switch signal and either the pressure change or the current draw
change is above 5 psi or above 1.5A, respectively.
4 psia when the valve opens for 10 seconds. Otherwise, it fails.
The test records the suction pressure during the open valve position
and passes if the suction pressure increase is above 3 psi when the
valve opens for 10 seconds.
that the HPS opens and closes properly.
Switch Test is skipped if sensed ambient temperature is less than 7.2°C (45°F),
return air temperature is less than -17.8°C (0°F), or the water pressure
switch is open.
With the unit running, the condenser fan is turned off and a 900 second
(15 minute) timer is started. The right display shows Discharge Pres-
sure if the sensor is configured and valid, else Discharge Temperature.
The unit needs to disable Discharge Pressure limit and enable Current
Limit checks.
The test fails immediately if:
-Ambient Temperature Sensor invalid
-Composite Return Temperature Sensor invalid
-HPS is open
The test fails if:
-HPS fails to open before 900 seconds total test time.
-Evaporator or Compressor IP Alarm.
-Calculated Dome Temperature exceeds 137.78°C (280°F).
-Discharge pressure exceeds 370 psig.
-Compressor Current exceeds limits
The test passes if HPS opens within the 15 minute time limit.
Switch If return temperature greater than -2.4°C, set setpoint to -5.0°C, else set
setpoint to -30°C. Restart unit according to normal startup logic. Run
unit normally for 120 seconds.
The test passes if the high pressure switch closes within 75 seconds af-
ter end of Test 7-0, else the test fails.
Test P7-0 must pass for this test to execute.
July 2017 issue of TechLine
NOTE
NOTE
4–54
for a procedure to assist the