Mitsubishi Electric PURY-HP144, Service Handbook

Page: 277 / 398

[8-9 Troubleshooting Problems with Major Components on BC Controller ]
36
- chapter 8 HWE18220_GB
8 Troubleshooting Based on Observed Symptoms
8-9-3 Troubleshooting Flowchart for LEVs
Check whether the electric expansion
valve and the solenoid valve connector
are not disconnected or not loose.
Run the cooling operation or the heating
operation in the system in trouble
(only in one system).
No cooling capacity
No heating capacity
Repair the fault. Fault is found.
Note 1
NO
Check that LEV1 is fully open. Check that LEV1 is fully closed.
Check that SVA and SVC are ON.
Check that SVA and SVC are OFF.
Cooling or heating operation
Note 2
Heating operation
Check whether LEV3 is controlling
superheat.
Check LEV1.
Check LEV3.
Check SVA and SVC.
Check SVB.
LEV1 is fully open.
Check whether LEV 3 is controlled by
the value of the differential pressure.
LEV1 is fully closed.
Note 3
Note 2
Note 3
YES
NO
Cooling operation
Superheat control OK Differential pressure OK
YES
NO
Check that SVB is OFF. Check that SVB is ON.
SVA, SVC ON SVA, SVC OFF
YES
YES
NO
Completed
SVB OFF SVB ON
YES
YES
YES
YES
NO
NO
NO
NO
NO
Check whether LEV4 is fully closed.
Check LEV4.
LEV4 is fully closed.
YES
Differential pressure OK
YES
NO NO
Check whether LEV4 is controlled by
the value of the differential pressure.