Mitsubishi Electric EHPT20Q-VM2EA Service Manual page 46

No. Fault symptom
1. Incorrect setting of the energy monitor
25 The energy monitor val-
ue seems not correct.
Note:
There could be some
discrepancies between the
actual and the calculated
values.
If you seek for accuracy,
please make sure to
connect power meter(s)
and heat meter to FTC
board. Both should be
locally supplied.
2. Non-connectable type of external meter (local
supply) is connected.
3. External meter (local supply) failure
4. FTC board failure
Annual Maintenance
It is essential that the cylinder unit is serviced at least once a year by a qualified individual. Any spare parts required should be purchased from Mitsubishi Electric.
NEVER bypass safety devices or operate the unit without them being fully operational.
<Annual maintenance points>
Use the Annual Maintenance Log Book as a guide to carrying out the necessary checks on the cylinder unit and outdoor unit.
GCH15010
Possible cause Explanation - Solution
1. Check the setting by following the procedure below.
(1) Check if the DIP switch is set as the table below.
Consumed electric energy
Electric energy meter
SW3-4
(Local supply)
OFF Without
ON With
(2) In the case external electric energy meter and/or heat meter is not used,
check if the setting for electric heater and water pump 1 input is correct by
referring to <Energy monitor setting> in section 9-4.
(3) In the case external electric energy meter and/or heat meter is used, check
if the unit of output pulse on external meter matches with the one set at the
main remote controller by referring to <Energy monitor setting> in section
9-4.
2. Check if the external meter (local supply) is connectable type by referring to
<Energy monitor setting>" in section 9-4.
3. Check if signal is sent to IN8 to IN10 properly. (Refer to section 6. WIRING
DIAGRAM)
Replace the external heat meter if defective.
4. Check the FTC control board.
If no problem found with the wiring, the FTC control board is faulty. Replace
the board.
46
Delivered heat energy
Heat meter
SW3-8
(Local supply)
OFF Without
ON With