Mitsubishi Electric PUHZ-RP3VHA Technical & Service Manual page 31

Error Code Meaning of error code and detection method
Abnormal temperature of heat sink
Abnormal if heat sink thermistor(TH8)
detects temperature indicated below.
RP3VHA··············77:
RP4~RP6VHA·····85:
U5
(4230)
Abnormality of power module
Check abnormality by driving power module
in case overcurrent is detected.
(UF or UP error condition)
U6
(4250)
Abnormality of super heat due to low
discharge temperature (RP3VHA)
Abnormal if discharge super heat is contin-
uously detected less than or equal to 0:
for 3 minutes even though linear expansion
valve has minimum open pulse after com-
U7
pressor starts operating for 10 minutes.
(1520)
(RP3VHA only)
Abnormality such as overvoltage or
voltage shortage and abnormal
synchronous signal to main circuit
Abnormal if any of followings are detected
during compressor operation;
• Decrease of DC bus voltage to 310V
• Instantaneous decrease of DC bus voltage
to 200V
• Increase of DC bus voltage to
RP3VHA : 420V
U9
• Decrease of input current of outdoor unit
(4220)
to 0.5A only if operation frequency is more
than or equal to 40Hz or compressor
current is more than or equal to 5A.
1 Outdoor fan is blocked.
2 Failure of outdoor fan motor
3 Air flow path is clogged.
4 Rise of ambient temperature
5 Defective thermistor
6 Defective input circuit of out-
door power board
7 Failure of outdoor fan drive cir-
cuit
1 Outdoor stop valve is closed.
2 Decrease of power supply volt-
age
3 Looseness, disconnection or
converse of compressor wiring
connection
4 Defective compressor
5 Defective outdoor power board
1 Disconnection or loose connec-
tion of discharge temperature
thermistor (TH4)
2 Defective holder of discharge
temperature thermistor
3 Disconnection or loose connection
of linear expansion valve's coil
4 Disconnection or loose connec-
tion of linear expansion valve's
connector
5 Defective linear expansion
valve
1 Decrease of power supply voltage
2 Disconnection of compressor
wiring
3 Defective 52C
4 Disconnection or loose connec-
tion of CN52C
5 Defective PFC module of outdoor
power board (RP3VHA only)
6 Defective ACT module
(RP4~6VHA only)
RP4-6VHA : 400V
7 Defective ACT module drive
circuit of outdoor power board
(RP4~6VHA only)
8 Disconnection or loose connec-
tion of CNAF (RP4~6VHA only)
9 Defective 52C drive circuit of
outdoor control board
0 Disconnection or loose connec-
tion of CN5
1 Disconnection or loose connec-
tion of CN2
31
Case
12 Check outdoor fan.
Refer to P39.
3 Check air flow path for cooling.
4 Check if there is something which causes
temperature rise around outdoor unit.
(Upper limit of ambient temperature is 46:.)
Turn off power, and on again to check if U5
is displayed within 30 minutes.
If U4 is displayed instead of U5, follow the
action to be taken for U4.
5 Check the resistance value of thermistor or
temperature by microcomputer.
(A-Control Service Tool : Refer to P53-60.)
Refer to P39.
6 Replace outdoor power board.
7 Replace outdoor controller board.
1 Open stop valve.
2 Check facility of power supply.
3 Correct the wiring (U•V•W phase) to com-
pressor.
4 Check compressor referring to P39.
5 Replace outdoor power board.
12 Check the installation conditions of dis-
charge temperature thermistor.
3 Check the coil of linear expansion valve.
Refer to P42.
4 Check the connection or contact of LEV-A
and LEV-B on outdoor controller board.
5 Check linear expansion valve.
Refer to P39.
1 Check the facility of power supply.
2 Correct the wiring (U•V•W phase) to com-
pressor.
3 Replace 52C.
4 Check CN52C wiring.
5 Replace outdoor power board. (RP3VHA
only)
6 Replace ACT module. (RP4-6VHA only)
7 Replace outdoor power board. (RP4-6VHA
only)
8 Check CNAF wiring. (RP4-6VHA only)
9 Replace outdoor controller board.
0 Check CN5 wiring.
1 Check CN2 wiring.
Judgment and action