Service manual

ManualsBrandsMitsubishi ManualsHeat PumpPUHZ-SW120YHA.UK

LED indications of fan operating condition (LED5 and LED6 on controller board) RP1.6-RP6VHA only.

Operation LED5/LED6 (Red)

Lit

Normal (Stop)

Normal (Operating)

Fan stops.

Controller board is outputting waveform for fan driving.

Contents

Operation

LED5/LED6 (Red)

Importance

2 blinks 1

6 blinks

8 blinks

7 blinks

Abnormal

is detected

Abnormality of bus voltage: Abnormal if bus voltage inspected for 1.5msec. is less than 60V or more than 390V.

Abnormality of overcurrent: Abnormal if current value of DC bus in fan controller board is over the cut-off point.

Abnormality of startup failure: Abnormal if the operating speed does not reach 100rpm even 12 sec passed after startup.

Abnormality of position detection: Abnormal if the position of U-phase cannot be detected after starting up fan.

Abnormality of disconnection: Abnormal if the first pattern of U/V/W-phase position detected after startup is H/H/H or L/L/L.

Meaning of error code and detection method

Remark

These

LEDs

are not

used

for

service.

Indication Error

Error

code

Outdoor controller board

Contents Inspection method

LED1 (Green)

LED2 (Red)

3 blinking 1 blinking

2 blinking

3 blinking

W1 Error code displayed on remote controller

W2 Refer to service manual for indoor unit.

4 blinking

5 blinking

6 blinking

7 blinking

1 blinking

2 blinking

3 blinking

4 blinking

Abnormality of shell thermostat

and discharging temperature (TH4)

Abnormality of super heat due

to low discharge temperature

1Check if stop valves are open.

2Check if connectors (TH4, LEV-A, and LEV-B) on outdoor controller board are not

disconnected.

3Check if unit fills with specified amount of refrigerant.

4Measure resistance values among terminals on indoor valve and outdoor linear

expansion valve using a tester.

Abnormal high pressure (High

pressure switch 63H worked.)

Abnormality of outdoor fan

motor rotational speed

1Check if indoor/outdoor units have a short cycle on their air ducts.

2Check if connector (63H) on outdoor controller board is not disconnected.

3Check if heat exchanger and filter is not dirty.

4Measure resistance values among terminals on linear expansion valve using a

tester.

1Check if stop valves are open.

2Check looseness, disconnection, and converse connection of compressor wiring.

3Measure resistance values among terminals on compressor using a tester.

4Check if outdoor unit has a short cycle on its air duct.

Compressor over current breaking (Start-up locked)

Compressor over current breaking

Abnormality of current sensor (P.B.)

Abnormality of power module

Open/short of discharge thermistor (TH4)

Open/short of outdoor ther-

mistor (TH8)

Open/short of outdoor thermistors

(TH3, TH6, TH7 and TH8)

Check if connectors (TH3, TH4, TH6 and TH7) on outdoor controller board and conn-

ector (CN3) on outdoor power board are not disconnected.

Measure resistance value of outdoor thermistors.

Abnormality of radiator panel

temperature

1Check if indoor/outdoor units have a short cycle on their air ducts.

2Measure resistance value of outdoor thermistor(TH8).

1Check the outdoor fan motor.

Abnormality of voltage 1Check looseness, disconnection, and converse connection of compressor wiring.

2Measure resistance value among terminals on compressor using a tester.

3Check the continuity of contactor (52C).

4Check if power supply voltage decreases.

5Check the wiring of CN52C.

6Check the wiring of CNAF. (RP4~6VHA only)

Abnormality of room temperature thermistor (TH1)

Abnormality of pipe temperature thermistor /Liquid (TH2)

Abnormality of pipe temperature

thermistor/Condenser-Evaporator

1Check if connectors (CN20, CN21 and CN29) on indoor controller board are not

disconnected.

2Measure resistance value of indoor thermistors.

Abnormality of drain sensor (DS)

Indoor drain overflow protection

1Check if connector (CN31) on indoor controller board is not disconnected.

2Measure resistance value of indoor thermistors.

3Measure resistance value among terminals on drain-up machine using a tester.

4Check if drain-up machine works.

5Check drain function.

Freezing (cooling)/overheating

(heating) protection

1Check if indoor unit has a short cycle on its air duct.

2Check if heat exchanger and filter is not dirty.

3Measure resistance value on indoor and outdoor fan motors.

4Check if the inside of refrigerant piping is not clogged.

Abnormality of pipe

temperature

1Check if indoor thermistors (TH2 and TH5) are not disconnected from holder.

2Check if stop valve is open.

3Check converse connection of extension pipe. (on plural units connection)

4Check if indoor/outdoor connecting wire is connected correctly. (on plural units

connection)

W3 LED1 on power board for RP4-6VHA.

1 blink: Power is supplied. 3 blinks:

Power is supplied to warm up compressor.

2 blinks: Power is supplied to compressor. Blinking: Limited control is being performed.

P.37

P.39

P.37

P.39

P.40

P.39

P.38

P.39

Detailed

reference

page

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