Mitsubishi Electric PUZ-HWM140VHA Service Manual page 21

Check Code Abnormal point and detection method
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
EA minutes.
(6844) 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.
Eb controller number cannot be set within
(6845) 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
(6846)
Incorrect connection
The outdoor unit does not receive the
EE
signals of I/F or FTC.
(7130)
OCH748
Cause
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.
1 A device other than Interface
unit or Flow temp. controller
unit is connected to the unit.
21
Judgment and action
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.
1 Connect I/F or FTC to the unit.