Mitsubishi Electric EHST20C-VM6HB Service Manual page 28

11-2. SELF-DIAGNOSIS ACTION TABLE
<Abnormalities detected when the power is turned on>
Check code Abnormal point and detection method
None
63L connector open (SW100/120 only)
Abnormal if 63L connector circuit is open for
3 minutes continuously after power supply.
63L: Low-pressure switch
F3
63H connector open
Abnormal if 63H connector circuit is open for
3 minutes continuously after power supply.
63H: High-pressure switch
F5
OCH533D
1 No voltage is supplied to terminal
block (TB1) of outdoor unit.
a) Power supply breaker is
turned off.
b) Contact failure or
disconnection of power
supply terminal
c) Open phase (L or N 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
SW75V: Disconnection of
connector R or S
SW100/120V:
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
or ACL)
5 Disconnection of outdoor noise
filter circuit board or parts failure
in outdoor noise filter circuit
board
As for SW75VHA(R3), it is
especially needed to check the
resistance RS on the noise filter
circuit board.
6 Defective outdoor power circuit
board
7 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 working due to
refrigerant 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 working due to defective
parts.
4 Defective outdoor controller
circuit board
Note: Refer to indoor unit section for code P and code E.
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
SW75V: Check connection of the connec-
SW100/120V: Check connection of the
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(V)/the
noise filter(Y). Refer to "11-6. TEST POINT
DIAGRAM".
4 Check connection of reactor. (DCL or ACL)
SW75VHA(R3) : Check connection of "LO" and
SW75VHAR4:Check connection of "TBL2" and
SW100/120V: Check connection of "DCL1"
5 a) Check connection of outdoor noise filter
circuit board.
b) Replace outdoor noise filter circuit board.
Refer to "11-6. TEST POINT DIAGRAM".
6 Replace outdoor power circuit board.
7 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 "11-6. TEST POINT DIAGRAM".
2 Check the 63L side of connecting wire.
3 Check refrigerant pressure.
Charge additional refrigerant.
Check continuity by 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 "11-6. TEST POINT DIAGRAM".
2 Check the 63H side of connecting wire.
3 Check continuity by tester.
Replace the parts if the parts are defective.
4 Replace outdoor controller circuit board.
28
Judgment and action
tor R or S. Refer to "11-6. TEST
POINT DIAGRAM".
connector LI or NI.
Refer to "11-6. TEST POINT
DIAGRAM".
"NO" on the outdoor noise filter
circuit board. Check connection
of "R" and "S" on the outdoor
power circuit board. Refer to
"11-6. TEST POINT DIAGRAM".
"TBL4" on the outdoor power cir-
cuit board. "11-6. TEST POINT
DIAGRAM".
and "DCL2" on the outdoor
power circuit board. Refer to
"11-6. TEST POINT DIAGRAM".