Mitsubishi Electric MFZ-KA35VA User Manual

WALL-MOUNTED Cooling Only/Fixed Speed Heat PumpM series
C-153
TROUBLESHOOTING
WALL- MOUNTED
C.1.8 TROUBLESHOOTING
MSC-GE20VB MSC-GE25VB MSC-GE35VB
Troubleshooting check table
C.1.8.1 Cooling Only/Fixed Speed Heat Pump
2.5-second OFF
Right lamp flash
7-time flash
2.5-second OFF
0.5-second ON
0.5-second OFF
MUH-GA/
MXZ
Mis-wiring/
or Serial
signal
Outdoor unit
does not run.
Serial signal from outdoor unit stops for 4 to 5
seconds.
5
Outdoor unit
does not run.
The compressor operation is
continuously three times interrupted by over
current protection within 1 minute after
start-up, it stops operation.
5-time flash
2.5-second OFF
MXZ
Outdoor
power
system
No.
1
2
4
7
8
SymptomOperation indicator lamp Condition
MUH/
MXZ
Outdoor
thermistor
MUH/
MXZ
Outdoor
control
system
Indoor coil
thermistor
<Thermistor short>
Thermistors are abnormal when they short
after compressor start-up.
<Thermistor open>
Thermistors are abnormal when they open
after compressor start-up.
However, discharge temperature thermistor is
abnormal when open circuit is detected more
than 10 minutes after compressor start-up.
It cannot properly read data in the nonvolatile
memory of the outdoor P.C. board, outdoor
unit stops.
3
Indoor fan
motor
Abnormal
point
Room
temperature
thermistor
2-time flash
2.5-second OFF
Indoor coil/room temperature thermistor
detects short or open circuit every 8 seconds
during operation.
3-time flash
2.5-second OFF
Indoor fan repeats
12 seconds ON
and 3minutes OFF.
When the indoor
fan breaks, the fan
keeps stopping.
The rotational frequency feedback signal is
not emitted for 12 seconds after indoor fan
motor is operated.
4-time flash
2.5-second OFF
Indoor
control
system
It cannot properly read data in the nonvolatile
memory of the indoor electronic control P.C.
board.
Outdoor unit
does not
operate.
Outdoor unit
does not
operate.
6-time flash
2.5-second OFF
Outdoor unit
does not
operate.
Outdoor unit
does not
operate.
6
MXZ
Outdoor
refrigerant
system
error
The compressor operation has been
interrupted by LEV protection continuously 5
minutes, the compressor stops operation.
Outdoor unit
does not run.
10-time flash
2.5-second OFF
No.
SymptomOperation indicator lamp Condition
Abnormal
point
The operation mode of each indoor unit
is differently set to COOL(includes DRY) and
HEAT at same time, the operation mode of
indoor unit that has operated at first has the
priority.
MXZ
Operation
mode
setting
Outdoor unit
operates but
indoor unit
does not run.
1
Lighted
Blinking
Not lighted
Lighted
Blinking
Not lighted
• Before taking measures, make sure that the symptom reappears for accurate troubleshooting.
When the indoor unit has started operation and the following detection method has detected an abnormality
(the first detection after the power ON), the indoor electronic control P.C. board turns OFF the indoor fan motor
with the OPERATION INDICATOR lamp flashing.
∙ Flashing of the OPERATION INDICATOR lamp (the left-hand side lamp)
indicates possible abnormalities.
∙ Flashing of OPERATION INDICATOR lamp (right-hand side lamp) indicates
abnormality.
∙ OPERATION INDICATOR lamp (left-hand side lamp) is lighted.

Mitsubishi Electric MFZ-KA35VA Specifications

General

Brand	Mitsubishi Electric
Model	MFZ-KA35VA
Category	Air Conditioner
Language	English