Mitsubishi Electric PSA-RP71KA Service Manual page 17

Abnormal point and detection method
Check Code
Indoor/outdoor unit communication
error (Transmitting error)
Abnormal if "1" receiving is detected 30
E7
times continuously though indoor controller
board has transmitted "0".
Indoor controller board
Abnormal if data cannot be read normally
from the nonvolatile memory of the indoor
Fb
controller board.
Remote controller control board
1 Abnormal if data cannot be read nor-
mally from the nonvolatile memory of the
E1
remote controller control board.
or
(Check code: E1)
E2
2 Abnormal if the clock function of remote
controller cannot be operated normally.
(Check code: E2)
Abnormal if a connection of indoor unit
and outdoor unit which uses different
refrigerant is detected.
EE
Forced compressor stop
(due to water leakage abnormality)
1 When the intake temperature subtracted
with liquid pipe temperature is less than
−10:, drain sensor is detected whether
it is soaked in the water or not at the
interval of 90 seconds. (Drain pump will
start operating when the drain sensor is
detected to be soaked in the water.)
2 The unit has a water leakage abnormality
when the following conditions, a and b,
are satisfied while the above-mentioned
detection is performed.
a) The drain sensor is detected to be
soaked in the water 10 times in a row.
PA
b) The intake temperature subtracted
with liquid pipe temperature is detected
to be less than −10: for a total of 30
minutes.
(When the drain sensor is detected to be
NOT soaked in the water, the detection
record of a and b will be cleared.)
3 The drain sensor detection is performed
in operations other than cooling. (When
the unit stops operating, during heating
or fan operation, when the unit stops
because of some abnormality)
Note: Once the water leakage abnormality
is detected, abnormality state will
not be released until the main
power is reset.
Abnormal refrigerant circuit
During Cooling, Dry, or Auto Cooling
operation, when the following are
regarded as failures when detected for
one second.
a) The compressor continues to run for 30
or more seconds.
PL
b) The liquid pipe temperature or the
condenser/evaporator temperature is
75°C or more.
These detected errors will not be
cancelled until the power source is
reset.
OCH528B
Cause
1 Defective transmitting receiving
circuit of indoor controller board
2 Noise has entered into power
supply.
3 Noise has entered into outdoor
control wire.
1 Defective indoor controller
board
1 Defective remote controller
1 Unauthorized connection of
indoor unit and outdoor unit
Connections other than below
combination are not authorized;
Outdoor unit: Models with R32 refrigerant
Indoor unit: Floor standing type indoor
unit (PSA-KA)
1 Drain pump trouble
2 Drain defective
· Drain pump clogging
· Drain pipe clogging
3 Open circuit of drain sensor
side heater
4 Contact failure of drain sensor
connector
5 Dew condensation on drain
sensor
· Drain water descends along
lead wire.
· Drain water waving due to filter
clogging.
6 Extension piping connection
difference at twin, triple,
quadruple system.
7 Mis-wiring of indoor/ outdoor
connecting at twin, triple,
quadruple system.
8 Room temperature thermistor/
liquid pipe temperature
thermistor detection is defective.
1 Abnormal operation of 4-way
valve
2 Disconnection of or leakage in
refrigerant pipes
3 Air into refrigerant piping
4 Abnormal operation (no rotation)
of indoor fan
· Defective fan motor.
· Defective indoor control board.
5 Defective refrigerant circuit
(clogging)
17
Countermeasure
1–3 Turn the power off, and on again to
check. If abnormality generates again,
replace indoor controller board.
1 Replace indoor controller board.
1 Replace remote controller.
1 Alter the connection referring to the combi-
nation as shown in the "cause" column.
1 Check the drain pump.
2 Please confirm whether water can be
drained.
3 Confirm the resistance of the drain sensor.
4 Check the connector contact failure.
5 Check the drain sensor lead wire mounted.
Check the filter clogging
6 Check the piping connection.
7 Check the indoor/ outdoor connecting wires.
8 Check the room temperature display of
remote controller.
Check the indoor liquid pipe temperature
display of outdoor controller board.
1 When this error occurs, be sure to replace
the 4-way valve.
2 Check refrigerant pipes for disconnection or
leakage.
3 After the recovery of refrigerant, vacuum dry
the whole refrigerant circuit.
4 Refer to section "9-4-2. DC Fan motor (fan
motor/indoor controller board)".
5 Check refrigerant circuit for operation.
To avoid entry of moisture or air into
refrigerant circuit which could cause
abnormal high pressure, purge air in
refrigerant circuit or replace refrigerant.