Mitsubishi Electric Mr.SLIM PC-2GAKD Technical & Service Manual page 30

Abnormal point and detection method
Error Code
Freezing/overheating protection is
working
1 Freezing protection (Cooling mode)
The unit is in 6-minute resume prevention
mode if pipe temperature stays under
-15: for 3 minutes, 3 minutes after the
compressor started. Abnormal if it stays
under -15: for 3 minutes again within
16 minutes after 6-minute resume pre-
vention mode.
<Frost prevention mode>
P6
If pipe temperature is 1: or below
when 16 minutes has passed after com-
pressor starts operating, unit will start
operating in frost prevention mode which
stops compressor operation. After that,
when pipe temperature stays 10: or
more for 3 minutes, frost prevention
mode will be released and compressor
will restart its operation.
Pipe temperature
<Cooling mode>
Detected as abnormal when the pipe tem-
perature is not in the cooling range 3 min-
utes after compressor start and 6 minutes
after the liquid pipe is out of cooling range.
Note 1) It takes at least 9 minutes to
detect.
Note 2) Abnormality P8 is not detected in
drying mode.
P8
Cooling range : -5 deg ] (TH2-TH1)
TH2: Liquid pipe temperature
TH1: Intake temperature
Outdoor unit
Remote controller transmission
error(E0)/signal receiving error(E4)
1 Abnormal if main or sub remote con-
troller cannot receive any transmission
normally from indoor unit of refrigerant
address "0" for 3 minutes.
(Error code : E0)
2 Abnormal if sub remote controller could
not receive for any signal for 2 minutes.
(Error code: E0)
1 Abnormal if indoor controller board can
E0
not receive any data normally from
or
remote controller board or from other
E4
indoor controller board for 3 minutes.
(Error code: E4)
2 Indoor controller board cannot receive
any signal from remote controller for 2
minutes. (Error code: E4)
Cause
(Cooling or drying mode)
1 Clogged filter (reduced airflow)
2 Short cycle of air path
3 Low-load (low temperature)
operation out of the tolerance
range
4 Defective indoor fan motor
• Fan motor is defective.
• Indoor controller board is
defective.
5 Defective outdoor fan control
6 Overcharge of refrigerant
7 Defective refrigerant circuit
(clogs)
1 Slight temperature difference
between indoor room
temperature and pipe tempera-
ture thermistor
• Shortage of refrigerant
• Disconnected holder of pipe
thermistor
• Defective refrigerant circuit
2 Converse connection of
extension pipe (on plural units
connection)
3 Converse wiring of indoor/
outdoor unit connecting wire
(on plural units connection)
4 Defective detection of indoor
room temperature and pipe
temperature thermistor
5 Stop valve is not opened
completely.
1 Wrong wiring of indoor/outdoor
connecting wire
2 Reversed phase
3 Protection device is working.
1 Contact failure at transmission
wire of remote controller
2 All remote controllers are set
as "sub" remote controller. In
this case, E0 is displayed on
remote controller, and E4 is
displayed at LED (LED1, LED2)
on the outdoor controller circuit
board.
3 Miswiring of remote controller
4 Defective transmitting receiving
circuit of remote controller
5 Defective transmitting receiving
circuit of indoor controller board
of refrigerant address "0"
6 Noise has entered into the
transmission wire of remote
controller.
30
Countermeasure
(Cooling or drying mode)
1 Check clogs of the filter.
2 Remove shields.
4 Measure the resistance of fan motor's winding.
Measure the output voltage of fan's connector
(FAN) on the indoor controller board.
WThe indoor controller board should be
normal when voltage of AC 220~240V is
detected while fan motor is connected.
Refer to 7-7.
5 Check outdoor fan motor.
67 Check operating condition of refrigerant
circuit.
1~4Check pipe temperature with room
temperature display on remote controller.
23Check converse connection of extension
pipe or converse wiring of indoor/outdoor
unit connecting wire.
1 Check the indoor/outdoor connecting wire.
2 Change the connection of electric wiring.
3 Check the protection device.
1 Check disconnection or looseness of indoor
unit or transmission wire of remote controller.
2 Set one of the remote controllers "main",
if there is no problem with the action above.
3 Check wiring of remote controller.
• Total wiring length: max. 500m
(Do not use cable x 3 or more.)
• The number of connecting indoor units:
max. 16 units
• The number of connecting remote con-
troller: max. 2 units
When it is not the above-mentioned problem of
1~3
4 Diagnose remote controllers.
a) When "RC OK" is displayed,
remote controllers have no problem.
Turn the power off, and on again to
check. If abnormality generates again,
replace indoor controller board.
b) When "RC NG" is displayed,
replace remote controller.
c)When "RC E3" or "ERC 00-66" is dis-
played, noise may be causing abnormali-
ty.
∗ If the unit is not normal after replacing
indoor controller board in group control,
indoor controller board of address "0"
may be abnormal.