Annual Maintenance - Mitsubishi Electric EHST17D-YM9D Service Manual

No. Fault symptom
1. Incorrect setting of the energy monitor
35 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.
3.
4. FTC board failure
Smart grid ready input (IN11 and IN12) is used,
36 Heat pump is forced to
and switch-on and off commands are input.
turn ON and OFF.

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.
OCH714B
Possible cause
Non-connectable type of external meter
(local supply) is connected.
External meter (local supply) failure
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(s) input is correct
by referring to <Energy monitor setting> in "9-5. Service menu".
(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 "9-5. Service menu".
2. Check if the external meter (local supply) is connectable type by referring to
<Energy monitor setting>" in "9-5. Service menu".
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.
• Check for faulty wiring.
• If no problem found with the wiring, the FTC control board is faulty.
Replace the board.
Normal operation no action necessary.
62
Delivered heat energy
Heat meter
SW3-8
(Local supply)
OFF Without
ON With