Mitsubishi Electric EHGT17D-YM9ED, Руководство по обслуживанию

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OCH722A
Error code Title and display conditions Possible Cause Diagnosis and action
L9 Low primary circuit (Zone2 side) flow rate
detected by flow switch
Note: “3” is displayed in “Request code: 569” in
“Running information”.
1. Insufficient system head 1. If more head required either add a pump of
the same size or replace existing pump.
2. Reduced flow in primary water circuit
Due to 1 or more of the following;
Faulty pump, insufficient air purge,
blocked strainer, leak in water circuit
2. Check circulation pump (See "9-6.
Checking Component Parts' Function" for
how to check).
Open purge valve to remove trapped air.
Check the strainer for blockages.
Check the primary water circuit for leaks.
Check that the flow amount is within the
recommended range.
3. Terminal wire has become detached
or loose wiring.
3. Visually check the IN7 terminal and
reattach if necessary.
4. Flow switch fault 4. Electrically test to determine fault.
5. Incorrect setting of the SW3-3 on the
FTC board
5. Check the SW3-3 setting on the FTC board.
6. FTC board failure 6. Replace board.
LC Boiler circulation water temperature overheat
protection
<DHW/Heating/LP/FS/OS>
Error code displayed when THWB1 detects a
temp. ≥80ºC for 10 consecutive seconds
1. The set temperature for Boiler is too
high.
1. Check if the set temperature for Boiler for
heating exceeds the restriction. (See the
manual for the thermistors "PAC-TH011HT-E")
2. Flow rate of the heating circuit from the
boiler may be reduced.
2. Check for
• water leakage
• strainer blockage
• water circulation pump function.
LD Boiler temperature thermistor (THWB1) failure
Refer to error codes (P1/P2/L5/LD).
LE Boiler operation error
<Heating>
Boiler is running and THW6 detects a
temperature <30ºC for consecutive 60 minutes.
1. THW6 has become detached from its
holder.
1. Visually inspect location and reattach as
necessary.
2. Incorrect wiring between FTC (OUT10)
and the boiler.
2. See the manual of the thermistors
"PAC-TH011HT-E".
3. Boiler fuel has run out or the system is
OFF.
3. Check the status of the boiler.
4. Boiler failure 4. Check the status of the boiler.
5. FTC board failure 5. Replace board.
LF Flow sensor failure Disconnection or loose connection of flow
sensor
Check flow sensor cable for damage or loose con -
nections.
LH Boiler circulation water freeze protection Flow rate of the heating circuit from the boil -
er may be reduced.
Check for
• water leakage
• strainer blockage
• water circulation pump function.
LJ DHW operation error (type of external plate HEX) 1. DHW tank water temp. thermistor
(THW5A/B) has become detached from
its holder.
2. Flow rate of the sanitary circuit may be
reduced.
1. Check for disconnection of DHW tank water
temp. thermistor (THW5A/B).
2. Check for water circulation pump function.
LL Setting errors of DIP switches on FTC control
board
Incorrect setting of DIP switches.
1. Boiler operation 1. For boiler operation, check that DIP SW1-1
is set to ON (With Boiler) and DIP SW2-6 is
set to ON (With Mixing Tank).
2. 2-zone temperature control 2. For 2-zone temperature control, check DIP
SW2-7 on the FTC board is set to ON
(2-zone) and DIP SW2-6 on the FTC board
is set to ON (With Mixing Tank).
P1 Indoor temperature thermistor (TH1) failure Refer to error codes (P1/P2/L5/LD).
P2 Indoor temperature thermistor (TH2) failure Refer to error codes (P1/P2/L5/LD).
E0/E4 Main remote controller communication failure
(Reception error)
Error code E0 is displayed if main remote control -
ler does not receive any signal from the FTC for
ref. address "0" for 3 minutes.
Error code E4 is displayed if FTC does not receive
any data from the main remote controller for 3
minutes or FTC does not receive any signal from
the main remote controller for 2 minutes.
1. Contact failure with transmission cable 1. Check connection cable for damage or
loose connections at the FTC and main
remote controller terminals.
2. Wiring procedure not observed.
(Cable length/cable diameter/number
of main remote controllers)
2. Check main remote controller and FTC
common wiring max cable length 500 m.
Only use 2-core cable.
Only connect 1 main remote controller to 1
FTC board.
3. Fault on the FTC board section
controlling Ref. address "0"
3. to 5.
If the problem is not solved by the above
measures then:
Turn the power to the unit OFF and then
ON.
If the E4 code is still displayed the FTC and/
or the main remote controller circuit board
should be replaced.
4. Fault with the main remote controller
circuit board
5. Electrical noise causes interference
with transmission/reception of data for
main remote controller.