Mitsubishi Electric PUHZ-W50VHA Service Manual page 54

Check Code Abnormal point and detection method
63H connector open
Abnormal if 63H connector circuit is open
for 3 minutes continuously from being
switched on.
63H: High pressure switch
F5
2 connector open
Abnormal if both 63H and 63L connector
circuits are open for 3 minutes continu-
ously from being switched on.
F9 63H: High pressure switch
63L: Low pressure switch
Miswiring of Interface unit/Flow temp.
controller-outdoor unit connecting wire
1. Outdoor controller circuit board can
automatically check the number of
connected Interface unit/Flow temp.
controller. Abnormal if the number can-
not be checked automatically due to
miswiring of Interface unit/Flow temp.
controller-outdoor unit connecting wire
and etc. after power is turned on for 4
minutes.
EA
2. Abnormal if outdoor controller circuit
board recognizes excessive number of
Interface unit/Flow temp. controller.
Miswiring of Interface unit/Flow temp.
controller-outdoor unit connecting wire
(reverse wiring or disconnection)
Outdoor controller circuit board can
automatically set the unit number of
Interface unit/Flow temp. controller.
Abnormal if the Interface unit/Flow temp.
controller number cannot be set within
Eb
4 minutes after power on because of
miswiring (reverse wiring or disconnection)
of Interface unit/Flow temp. controller-
outdoor unit connecting wire.
Startup time over
The unit cannot finish startup process
within 4 minutes after power on.
EC
OCH439M
Cause
1 Disconnection or contact fail-
ure of 63H connector on out-
door controller circuit board
2 Disconnection or contact fail-
ure of 63H
3 63H is working 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 working due
to defective parts.
4 Defective outdoor controller
board
1 Contact failure or miswiring
of Interface unit/Flow temp.
controller-outdoor unit
connecting wire
2 Diameter or length of Interface
unit/Flow temp. controller-
outdoor unit connecting wire is
out of specified capacity.
3 Excessive number of Interface
unit/Flow temp. controller is
connected to 1 outdoor unit.
(2 units or more)
4 Defective transmitting
receiving circuit of outdoor
controller circuit board
5 Defective transmitting
receiving circuit of Interface/
Flow temp. controller board
6 Noise has entered into power
supply or Interface/Flow
temp. controller-outdoor unit
connecting wire.
1 Contact failure or miswiring
of Interface unit/Flow temp.
controller-outdoor unit
connecting wire
2 Diameter or length of Interface
unit/Flow temp. controller-
outdoor unit connecting wire is
out of specified capacity.
4 Defective transmitting
receiving circuit of outdoor
controller circuit board
5 Defective transmitting
receiving circuit of Interface/
Flow temp. controller board
6 Noise has entered into power
supply or Interface unit/Flow
temp. controller-outdoor unit
connecting wire.
1 Contact failure of Interface unit
/Flow temp. controller-outdoor
unit connecting wire
2 Diameter or length of Interface
unit/Flow temp. controller-
outdoor unit connecting wire is
out of specified capacity.
6 Noise has entered into power
supply or Interface unit/Flow
temp. controller-outdoor unit
connecting wire.
54
Judgment and action
1 Check connection of 63H connector on
outdoor controller circuit board.
Refer to "9-6. TEST POINT DIAGRAM".
2 Check the 63H side of connecting wire.
3 Check for continuity of 63H.
Replace high pressure switch if it is defec-
tive.
4 Replace outdoor controller circuit board.
1 Check connection of connector (63H,63L) on
outdoor controller circuit board.
Refer to "9-6. TEST POINT DIAGRAM".
2 Check the 63H and 63L side of connecting
wire.
3 Check continuity of 63H and 63L.
Replace the pressure switch if it is defective.
4 Replace outdoor controller circuit board.
1 Check disconnection, looseness or polarity of
Interface unit/Flow temp. controller-outdoor
unit connecting wire of Interface unit/Flow
temp. controller and outdoor units.
2 Check diameter and length of Interface unit/
Flow temp. controller-outdoor unit connect-
ing wire.
Total wiring length: 80 m
(Including wiring connecting each Interface
unit/Flow temp. controller unit and between
Interface unit/Flow temp. controller and out-
door unit)
Also check if the connection order of flat
cable is S1, S2, S3.
3 Check the number of Interface unit/Flow
temp. controller that is connected to 1 out-
door unit. (If EA is detected.)
4–5 Turn the power off once, and on again to
check.
Replace outdoor controller circuit board
or Interface/Flow temp. controller board if
abnormality occurs again.
6 Check transmission path, and remove the
cause.
Note: The descriptions above, 1–6, are for
EA, Eb and EC.