Troubleshooting - Mitsubishi Electric PLFY-P20VEM-E Technical & Service Manual

8
TROUBLE SHOOTING
8-1. HOW TO CHECK THE PARTS
PLFY-P20VEM-E.UK
PLFY-P50VEM-E.UK
PLFY-P125VEM-E.UK
Parts name
Room temperature
detection thermistor (TH21)
Pipe temperature detection
thermistor/liquid (TH22)
Pipe temperature detection
thermistor/gas (TH23)
Vane motor (MV)
White
Orange
Red
Yellow
Blue
Drain pump (DP)
1
Red
2
Purple
3
Black
Drain float switch (FS)
Moving part
1
2
3
4
i-see Sensor
1 2 3 4
1 2 3 4
i-see Sensor motor
(MT) (Option)
White
Orange
Red
Yellow
Blue
Linear expansion
valve (LEV)
CN60
White
1
Yellow
2
Orange
3
LEV
Blue
4
Red
5
Brown
6
OCH657
PLFY-P25VEM-E.UK
PLFY-P63VEM-E.UK
Disconnect the connectors, then measure the resistance with a tester.
(At ambient temperatures of 10 to 30:)
Normal Abnormal
4.3–9.6 k" Open or short
Measure the resistance between the terminals with a tester.
(At ambient temperatures of 20 to 30:)
Connector
Red - Yellow (5-3, 0-8, 5-3, )-8)
Red - Blue (5-1, 0-6, 5-1, )-6)
Red - Orange (5-4, 0-9, 5-4, )-9)
Red - White (5-2, 0-7, 5-2, )-7)
1 Check if the drain float switch works properly.
2 Check if the drain pump works and drains water properly in cooling operation.
3 If no water drains, confirm that the check code 2502 will not be displayed 10 minutes after the
operation starts.
Note: The drain pump for this model is driven by the internal DC motor of controller board, so it is not
possible to measure the resistance between the terminals.
Normal
Red–Black: Input 13 V DC → The fan starts to rotate.
Purple–Black: Abnormal (check code 2502) if it outputs 0–13 V square wave (5 pulses/rotation),
and the number of rotation is not normal.
Measure the resistance between the terminals with a tester.
State of moving part Normal
UP Short
DOWN Open
Turn the power ON while the i-see Sensor connector is connected to the CN4Z on indoor
controller board. A communication between the indoor controller board and i-see Sensor
board is made to detect the connection.
Normal: When the operation starts, the motor for i-see Sensor is driven to rotate the i-see Sensor.
Abnormal: The motor for i-see Sensor is not driven when the operation starts.
Note: The voltage between the terminals cannot be measured accurately since it is pulse output.
Measure the resistance between the terminals with a tester.
(At ambient temperatures of 20 to 30°C)
Connector Normal
Red - Yellow
Red - Blue
Red - Orange
Red - White
Disconnect the connector then measure the resistance valve with a tester.
(At the coil temperatures of 10 to 30°C)
Normal
Connector
White-Red
Yellow-Brown
200 " ± 10%
Orange-Red
Blue-Brown
Refer to "8-1-2. Linear expansion valve".
PLFY-P32VEM-E.UK
PLFY-P80VEM-E.UK
Check points
(Refer to "8-1-1. Thermistor".)
Normal
300 "
Abnormal
Other than short
Other than open
Abnormal
Open or short
250 "
Abnormal
Open or short
22
PLFY-P40VEM-E.UK
PLFY-P100VEM-E.UK
Abnormal
Open or short
Switch
Magnet
Moving part