Troubleshooting - Mitsubishi Electric EHPT20Q-VM2EA Service Manual

10

TROUBLESHOOTING

10-1. Troubleshooting
<Summary of self diagnosis based on Error Codes and Service Procedures>
Present and past Error codes are logged and displayed on the main remote controller or control board of the outdoor unit.
Please refer to the table below and subsequent explanations to diagnose and remedy typical problems that may occur in the field.
Unit Condition
Reoccurring problem
Non reoccurring problem
NOTE
Electrical components should only be replaced as a final option. Please follow instructions in Tables 10-4. and 10-5. Error Codes and Inferior Phenomena
fully before resorting to replacing parts.
10-2. Test Run
Before a test run
After installation of outdoor unit, pipework and electrical wiring, recheck that there is no water leakage, loosened connections or miswiring.
Measure impedance between the ground and the power supply terminal block (L,N) on the outdoor and indoor units with suitable (500V) ohmmeter. Resistance
Read the Installation and Operation Manuals fully especially the safety requirements before carrying out any test runs.
10-3. Malfunction diagnosis method by main remote controller
If during start up or operation a malfunction occurs the error code screen may be displayed on the main remote controller.
The error code screen shows the following; code, unit, ref. address, and telephone number of installer (only if previously entered by the installer)
Please note in the case of some malfunctions an error code is not generated please refer to table 10-5. for more details.
To reset
1. To reset the main remote controller press F4 button (Reset).
2. Then press F3 (Yes) to confirm.
GCH15010
Error Code Action
Displayed Use table 10-4. "Self diagnosis and action" to identify fault and correct.
Not Displayed Use table 10-5. "Troubleshooting by inferior phenomena" to identify fault and correct.
Logged 1. Check temporary causes of defects such as the operation of safety devices on the refrigerant/water
circuit including compressor, poor wiring, electrical noise etc. Re-check the symptom and the instal-
lation environment, weather conditions at time of fault etc.
2. Reset Error code logs, Service the unit and restart system.
Not Logged
1. Recheck the abnormal symptom
2. Identify cause of problem and take corrective action according to Table 10-5. "Troubleshooting by
inferior phenomena"
3. If no obvious problem can be found continue to operate the unit.
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