Mitsubishi Electronics PCA-A24GA Cause Countermeasure Freezing/overheating protection is, Working

Page 16

Error Code

Abnormal point and detection method

Cause

Countermeasure

 

 

Freezing/overheating protection is

(Cooling or drying mode)

(Cooling or drying mode)

 

 

working

1 Clogged filter (reduced airflow)

1 Check clogs of the filter.

 

 

1 Freezing protection (Cooling mode)

2 Short cycle of air path

2 Remove shields.

 

 

The unit is in 6-minute resume prevention

3 Low-load (low temperature)

 

 

 

mode if pipe <liquid or condenser/evap-

operation out of the tolerance

 

 

 

orator> temperature stays under

range

 

 

 

-15:(5˚F) for 3 minutes, 3 minutes after

4 Defective indoor fan motor

4 Measure the resistance of fan motor's winding.

 

the compressor started. Abnormal if it

• Fan motor is defective.

Measure the output voltage of fan's connector

 

stays under -15:(5˚F) for 3 minutes

• Indoor controller board is

(FAN) on the indoor controller board.

 

 

again within 16 minutes after 6-minute

defective.

WThe indoor controller board should be

 

 

resume prevention mode.

 

normal when voltage of AC 208/230V is

 

 

 

 

detected while fan motor is connected.

 

 

 

 

Refer to 10-6.

 

 

 

5 Defective outdoor fan control

5 Check outdoor fan motor.

 

 

 

6 Overcharge of refrigerant

67 Check operating condition of refrigerant

 

 

7 Defective refrigerant circuit

circuit.

 

 

 

(clogs)

 

 

P6

2 Overheating protection (Heating mode)

(Heating mode)

(Heating mode)

 

 

1 Clogged filter (reduced airflow)

1 Check clogs of the filter.

 

 

The units is in 6-minute resume

2 Short cycle of air path

2 Remove shields.

 

 

prevention mode if pipe <condenser /

3 Overload (high temperature)

 

 

 

evaporator> temperature is detected as

operation beyond the tolerance

 

 

 

over 70:(158˚F) after the compressor

range

 

 

 

started. Abnormal if the temperature of

4 Defective indoor fan motor

4 Measure the resistance of fan motor's winding.

 

over 70:(158˚F) is detected again with-

• Fan motor is defective.

Measure the output voltage of fan's connector

 

in 10 minutes after 6-minute resume

• Indoor controller board is

(FAN) on the indoor controller board.

 

 

prevention mode.

defective.

WThe indoor controller board should be

 

 

 

 

normal when voltage of AC 208/230V is

 

 

 

 

detected while fan motor is connected.

 

 

 

 

Refer to 10-6.

 

 

 

5 Defective outdoor fan control

5 Check outdoor fan motor.

 

 

 

6 Overcharge of refrigerant

6~8Check operating condition of refrigerant

 

 

7 Defective refrigerant circuit

circuit.

 

 

 

(clogs)

 

 

 

 

8 Bypass circuit of outdoor unit

 

 

 

 

is defective.

 

 

 

 

 

 

 

 

Pipe temperature

1 Slight temperature difference

1~4 Check pipe <liquid or condenser /

 

 

<Cooling mode>

between indoor room

evaporator> temperature with room

 

 

Detected as abnormal when the pipe tem-

temperature and pipe <liquid

temperature display on remote controller

 

perature is not in the cooling range 3 min-

or condenser / evaporator>

and outdoor controller circuit board.

 

 

utes after compressor start and 6 minutes

temperature thermistor

Pipe <liquid or condenser / evaporator>

 

 

after the liquid or condenser/evaporator pipe

• Shortage of refrigerant

temperature display is indicated by setting

 

is out of cooling range.

• Disconnected holder of pipe

SW2 of outdoor controller circuit board as

 

Note 1) It takes at least 9 minutes to

<liquid or condenser /

follows.

 

 

detect.

evaporator> thermistor

 

)

 

Note 2) Abnormality P8 is not detected in

• Defective refrigerant circuit

Conduct temperature check with outdoor

 

drying mode.

2 Converse connection of

 

controller circuit board after connecting

 

 

 

 

Cooling range:-3 deg C[-5.4deg F]](TH-TH1)

extension pipe (on plural units

(‘A-Control Service Tool(PAC-SK52ST)’.

 

TH: Lower temperature between liquid pipe

connection)

 

 

 

temperature (TH2) and

3 Converse wiring of indoor/

23Check converse connection of extension

 

condenser/evaporator temperature

outdoor unit connecting wire

pipe or converse wiring of indoor/outdoor

 

(TH5)

(on plural units connection)

 

unit connecting wire.

 

P8

TH1: Intake temperature

4 Defective detection of indoor

 

 

 

 

<Heating mode>

room temperature and pipe

 

 

 

When 10 seconds have passed after the

<condenser / evaporator>

 

 

 

compressor starts operation and the hot

temperature thermistor

 

 

 

adjustment mode has finished, the unit is

5 Stop valve is not opened

 

 

 

detected as abnormal when

completely.

 

 

 

condenser/evaporator pipe temperature is

 

 

 

 

not in heating range within 20 minutes.

 

 

 

 

Note 3) It takes at least 27 minutes to

 

 

 

 

detect abnormality.

 

 

 

 

Note 4) It excludes the period of defrosting

 

 

 

 

(Detection restarts when defrosting

 

 

 

 

mode is over)

 

 

 

 

Heating range:3 deg C[5.4deg F][(TH5-TH1)

 

 

 

 

 

 

 

 

16

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Contents Contents Revised EDITION-BPCA-A24GA PCA-A30GATechnical Changes Technical Data BookReference Manual Safety Precaution Always Observe for SafetyWhen charging directly from cylinder Additional refrigerant chargePart Names and Functions Indoor UnitDisplay Section Operation Mode display Mode Select buttonTemperature setting display Timer displaySpecifications Service RefPCA-A30GA, PCA-A30GA1Single phase, 60Hz, 208/230V PCA-A36GA, PCA-A36GA1Single phase, 60Hz, 208/230VNoise Criterion Curves PCA-A24GA1PCA-A30GA1 PCA-A36GA1Outlines and Dimensions PCA-A24GA PCA-A24GA1 PCA-A30GA PCA-A30GA1PCA-A36GA PCA-A42GA PCA-A36GA1 PCA-A42GA1 Unit inchmmWiring Diagram Indoor unit Installation Manual Refrigerant System Diagram Heat exchangerTroubleshooting TroubleshootingSELF-DIAGNOSIS Action Table Cause Countermeasure Freezing/overheating protection is Pipe temperatureWorking Cause Countermeasure Pipe temperature thermistor Remote controller transmissionErrorE0/signal receiving errorE4 ErrorE3/signal receiving errorE5Error Signal receiving error Error Transmitting errorRemote controller control board Indoor controller boardTroubleshooting by Inferior Phenomena Phenomena Cause CountermeasureIs off Ply system4Receiver for wireless remote Is blinking3Upward/downward vane Performance failurePage Vane motor MV Between 1 to 3 12.6-13.7V DC Pin1 + Test Point DiagramConnect to the indoor controller board CN2D PCA-A36GA PCA-A36GA1 Functions of DIP Switch and Jumper Wire ModelsDisassembly Procedure Operating Procedure Photos & IllustrationsRemoving the air intake grille Removing the electrical boxOperating Procedure Removing the fan motor MFRemoving the sirocco fan Remove the air intake grilleOperating Procedure Photos Removing the vane motor MVRemoving the Indoor coil thermistor TH2/TH5 Removing the Under panelRemoving the drain pan Removing the guide vaneRemove the intake grille. See the figure Removing the Auto vaneRemoving the heat exchanger Parts No Parts Name Specifications Drawing NoR01 29J 130 R01 35J 130Structural Part PCA-A24GA PCA-A30GA PCA-A36GA PCA-A42GA Electrical Parts PCA-A24GA PCA-A30GA PCA-A36GA PCA-A42GA Parts Name Specifications RoHSRemarks Parts NoStructural Part PCA-A24GA1PCA-A30GA1PCA-A36GA1PCA-A42GA1 Electrical Parts PCA-A24GA1PCA-A30GA1PCA-A36GA1PCA-A42GA1 Wiring RecomRoHS Qty/ set