Check code
Location
of
detection
Description
System status
Check code detection
condition(s)
Check items (locations)
• Check switch setting of
outdoor P.C. board (I/F).
SW setting
trouble
All stop
Outdoor P.C. board (I/F)
does not operate normally.
L23
—
When external device is
connected:
1) Check for trouble in
external device.
2) Check for trouble in
indoor P.C. board.
When external device is
not connected:
1) Check for trouble in
indoor P.C. board.
Indoor external
interlock
(External
abnormal input)
Indoor unit
Detected indoor
address
Stop of
corresponding
unit
• Indoor unit has been shut
down due to external
abnormal input signal.
L30
L30
Main
remote
controller
Outdoor 7-segment display
Check
code
Sub-code
• Check No. of outdoor units
connected (Only up to 5
units per system allowed).
• Check communication
lines between outdoor
units.
• Check for failure in outdoor
P.C. board (I/F).
Too many
outdoor units
connected
I/F
All stop
There are more than 5
outdoor units.
L28
L28
—
Check outdoor P.C. board
(I/F).
Extended IC
trouble
I/F
Continued
operation
There is part failure in P.C.
board (I/F).
—
L31
—
• Check the lock of fan
motor (AC fan).
• Check wiring.
Indoor fan
motor trouble
Indoor unit
Stop of
corresponding
unit
P01
—
—
• Check outdoor service
valves (gas side, liquid
side) to confirm full
opening.
• Check outdoor PMVs
(PMV1, 2, 3, 4) for
clogging.
• Check resistance
characteristics of TD1
sensor.
• Check for insufficiency in
refrigerant quantity.
• Check for failure in 4-way
valve.
• Check for leakage of SV4
circuit.
• Check SV4 circuit (wiring
or installation trouble in
SV41 or SV42).
Discharge
temperature
TD1 trouble
I/F
All stop
Discharge temperature
(TD1) exceeds 115 ˚C.
P03
P03
—
•
•
•
Check model setting of
P.C. board for servicing
outdoor I/F P.C. board.
Check connection of UART
communication connector.
Check compressor P.C.
board, fan P.C. board, and
I/F P.C. board for failure.
Trouble in No.
of P.C. board
I/F
All stop
Insufficient number of P.C.
board are detected when
power is turned on.
L29
L29
Circle (O):
Trouble P.C. board
• Check model setting of
P.C. board for servicing
outdoor I/F P.C. board.
Outdoor
capacity not set
I/F
All stop
Initial setting of I/F P.C.
board has not been
implemented.
L10
L10
—
• Check central control
addresses.
Duplicated
central control
address
Network
adaptor
Indoor unit
All stop
There is duplication in
central control address
setting.
L20
—
—
• Check the model name of
the outdoor unit.
Outdoor model
incompatibility
trouble
I/F
All stop
Outdoor unit that cannot be
connected is connected.
L17
L17
—
• Check I/F P.C. board
exchange has been
correctly performed as a
procedure.
• Check for failure in I/F P.C.
board.
• Check for inverter P.C.
board for compressors and
inverter P.C. board for fan
The number of
inverter P.C.
boards is
abnormal.
All stop
I/F
00
When there is much number
of an inverter P.C. board to
model setting of an interface
P.C. board.
P.C.board
Compressor Fan Motor
01
02
03
08
09
0A
0B
10
O
O
O
O
O
O
O
O
O
O
O
O
O
2
111
11
12
13
18
19
1A
1B
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
02: HWM
(Hot Water Module)
I/F
- 188 -
Summary of Contents for MMY-MUP0801HT7JP
Page 309: ......
