Self-Diagnosis Action Table; Abnormalities Detected When The Power Is Turned On - Mitsubishi Electric SUZ-KA24NAHZ Service Manual

10-3. SELF-DIAGNOSIS ACTION TABLE

<Abnormalities detected when the power is turned on>
Check Code Abnormal point and detection method
None
OCH754A
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
outdoor power circuit board.
a) Contact failure of power
supply terminal
b) Open phase on the outdoor
power circuit board
Disconnection of connector
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
Note: Refer to indoor unit section for the codes starting with P and E.
Cause
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 connector LI or NI
Refer to "10-8. TEST POINT DIAGRAM".
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
"10-8. TEST POINT DIAGRAM".
4 Check connection of reactor. (DCL)
Refer to "7. WIRING DIAGRAM".
5 Replace outdoor power circuit board.
6 Replace controller board (When items
above are checked but the units cannot be
repaired).
26
Judgment and action