Troubleshooting - Mitsubishi Electric CITY MULTI PLFY Series Technical & Service Manual

9

TROUBLESHOOTING

9-1. HOW TO CHECK THE PARTS
Parts name
Thermistor (TH21)
(Room temperature detection)
Thermistor (TH22)
(Pipe temperature detection/inlet)
Thermistor (TH23)
(Pipe temperature detection/outlet)
Vane motor (MV)
White
M
Orange
Red
Blue Yellow
Fan motor (MF)
Drain pump (DP)
1 Red
Purple
2
Black
3
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 *
White
M
Orange
Red
Yellow
Blue
Pressure sensor
(Optional parts)
* i-see Sensor is available with optional "i-see Sensor corner panel" (SLP-18FAEU).
TCH123
Disconnect the connector then measure the resistance with a multimeter.
(At the ambient temperature 50°F ~ 86°F)
Normal Abnormal
Ω
4.3 to 9.6 k Open or short
Measure the resistance between the terminals with a multimeter.
(At the ambient temperature 68
Normal
Red–Yellow Red–Blue
Ω
300
Refer to "9-1-4. DC Fan motor (fan motor/indoor controller board)".
Check if the drain float switch works properly.
Check if the drain pump works and drains water properly in cooling operation.
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, so it is not possible to
measure the resistance between the terminals.
Normal
Red–Black: Input 13 VDC → 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 multimeter.
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 multimeter.
(At the ambient temperature 68°F ~ 86°F)
Normal
Red–Yellow Red–Blue
Ω
250
▪ Pressure sensor (inner water) PS1
▪ Pressure sensor (outlet water) PS2
1. Check that the pressure sensor is connected.
2. Check the pressure sensor wiring for breakage.
Pressure 0-1.0 MPa [145 psi] Vout 0.5-4.5 V
0.392 V/ 0.098 MPa [14 psi]
Pressure [MPa] = 0.25 × Vout [V] - 0.125
Pressure [psi] = (0.25 × Vout [V] - 0.125) × 145
Checkpoints
Refer to "9-2-1. Thermistor Characteristic Graph".
86 )
°F ~ °F
Red–Orange Red–White
± 7%
Abnormal
Other than short
Other than open
Red–Orange Red–White
± 7%
PS1
GND(RED)
Vout(Brown)
Vcc(DC5V)(Orange)
18
Abnormal
Open or short
Switch
Magnet
Moving
Part
Abnormal
Open or short
PS2
GND(Blue)
Vout(White)
Vcc(DC5V)(Yellow)
Connector
CNSA
(White)
Connector
CNSB
(Black)