Troubleshooting Flowchart For Levs - Mitsubishi Electric HP120TNU-A Service Handbook

[8-9 Troubleshooting Problems with Major Components on BC Controller ]
8-9-3

Troubleshooting Flowchart for LEVs

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