Self-Diagnosis Action Table - Mitsubishi Electric MXZ-8B48NA Technical & Service Manual

9-3. SELF-DIAGNOSIS ACTION TABLE

<Abnormalities detected when the power is turned on> (Note 1) Refer to indoor unit section for code P and code E.
Abnormal point and detection method
Error Code
None
63L connector open
Abnormal if 63L connector circuit is open
for 3 minutes continuously after power sup-
ply
63L: Low-pressure switch
F3
(5202)
63H connector open
Abnormal if 63H connector circuit is open
for 3 minutes continuously after power sup-
ply
F5
63H: High-pressure switch
(5201)
2 connector open
Abnormal if both 63H and 63L connector
circuits are open for 3 minutes continuously
after power supply
F9
(4119)
63H: High-pressure switch
63L: Low-pressure switch
1 No voltage is supplied to termi-
nal block (TB1) of outdoor unit.
a) Power supply breaker is
turned off.
b) Contact failure or disconnec-
tion of power supply terminal
c) Open phase (L1 or L2 phase)
2 Electric power is not charged to
power supply terminal of out-
door power circuit board.
a) Contact failure of power
supply terminal
b) Open phase on the outdoor
power circuit board
Disconnection of terminal LI
or NI.
—
3 Electric power is not supplied
to outdoor controller circuit
board.
a) Disconnection of connector
(CNDC)
4 Disconnection of reactor (DCL)
5 Defective outdoor power circuit
board
6 Defective outdoor controller
circuit board
1 Disconnection or contact failure
of 63L connector on outdoor
controller circuit board
2 Disconnection or contact failure
of 63L
3 63L is operating due to refriger-
ant leakage or defective parts.
4 Defective outdoor controller
circuit board
1 Disconnection or contact failure
of 63H connector on outdoor
controller circuit board
2 Disconnection or contact failure
of 63H
3 63H is operating due to defec-
tive parts.
4 Defective outdoor controller
circuit board
1 Disconnection or contact failure
of connector (63H,63L) on
outdoor controller circuit board.
2 Disconnection or contact failure
of 63H, 63L
3 63H and 63L are operating due
to defective parts.
4 Defective outdoor controller
board
Case
1 Check following items.
a) Power supply breaker
b) Connection of power supply terminal
block.
(TB1)
c) Connection of power supply terminal
block.
(TB1)
2 Check following items.
a) Connection of power supply terminal
block.
(TB1)
b) Connection of terminal on outdoor
power circuit board.
Disconnection of terminal LI or NI.
Refer to 9-7.
3 Check connection of the connector (CNDC)
on the outdoor controller circuit board.
Check connection of the connector (CNDC)
on the outdoor power circuit board.
Refer to 9-7.
4 Check connection of reactor. (DCL)
Check connection of "DCL1" and "DCL2"
on the power circuit board.
5 Replace outdoor power circuit board.
6 Replace controller board (When items
above are checked but the units cannot be
repaired.)
1 Check connection of 63L connector on
outdoor controller circuit board.
Refer to 9-7.
2 Check the 63L side of connecting wire.
3 Check refrigerant pressure.
Charge additional refrigerant.
Check continuity with a tester.
Replace the parts if the parts are defective.
4 Replace outdoor controller circuit board.
1 Check connection of 63H connector on
outdoor controller circuit board.
Refer to 9-7.
2 Check the 63H side of connecting wire.
3 Check continuity with a tester.
Replace the parts if the parts are defective.
4 Replace outdoor controller circuit board.
1 Check connection of connector (63H,63L) on
outdoor controller circuit board.
Refer to 9-7.
2 Check the 63H and 63L side of connecting
wire.
3 Check continuity with a tester.
Replace the parts if the parts are defective.
4 Replace outdoor controller circuit board.
42
Judgment and action