Mitsubishi Electric PUHZ-SW50VHA Service Manual page 21

Check Code Abnormal points and detection method
Miswiring of indoor/outdoor unit
connecting wire
1. Outdoor controller circuit board can
automatically check the number of
connected indoor units. Abnormal if the
number cannot be checked automatically
due to miswiring of indoor/outdoor unit
connecting wire, etc. after power is turned
on for 4 minutes.
2. Abnormal if outdoor controller circuit board
recognizes excessive number of indoor
units.
EA
Miswiring of indoor/outdoor unit
connecting wire (converse wiring or
disconnection)
Outdoor controller circuit board can
automatically set the unit number of indoor
units.
Abnormal if the indoor unit number can
not be set within 4 minutes after power
on because of Miswiring (converse wiring
or disconnection) of indoor/outdoor unit
connecting wire.
Eb
Start-up time over
The unit cannot finish start-up process within
4 minutes after power on.
EC
Incorrect connection
The outdoor unit does not receive the signals
of I/F or FTC.
EE
OCH525C
Case
1 Contact failure or miswiring of
indoor/outdoor unit connecting
wire
2 Diameter or length of indoor/
outdoor unit connecting wire is out
of specified capacity.
3 Excessive number of indoor units
are connected to 1 outdoor unit. (4
units or more)
4 Defective transmitting receiving
circuit of outdoor controller circuit
board
5 Defective transmitting receiving
circuit of indoor controller board
6 Defective indoor power board
7 2 or more outdoor units have
refrigerant address "0".
(In case of group control)
8 Noise has entered into power
supply or indoor/outdoor unit
connecting wire.
1 Contact failure or miswiring of
indoor/outdoor unit connecting
wire
2 Diameter or length of indoor/
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 indoor controller board
6 Defective indoor power board
7 2 or more outdoor units have
refrigerant address "0" .
(In case of group control)
8 Noise has entered into power
supply or indoor/outdoor unit
connecting wire.
1 Contact failure of indoor/outdoor
unit connecting wire
2 Diameter or length of indoor/out-
door unit connecting wire is out of
specified capacity.
7 2 or more outdoor units have
refrigerant address "0" .
(In case of group control)
8 Noise has entered into power sup-
ply or indoor/outdoor unit connect-
ing 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 or looseness or
polarity of indoor/outdoor unit connecting
wire of indoor and outdoor units.
2 Check diameter and length of indoor/
outdoor unit connecting wire.
Total wiring length: 80 m
(including wiring connecting each indoor
unit and between indoor and outdoor
unit)
Also check if the connection order of flat
cable is S1, S2, S3.
3 Check the number of indoor units that
are connected to 1 outdoor unit (If EA is
detected).
4–6 T urn the power off once, and on again
to check.
Replace outdoor controller circuit
board, indoor controller board or
indoor power board if abnormality
occurs again.
7 Check if refrigerant addresses (SW1-
3 to SW1-6 on outdoor controller circuit
board) are overlapping in case of group
control system.
8 Check transmission path, and remove the
cause.
Note: The descriptions above 1–8, are for
EA, Eb and EC.
1 Connect I/F or FTC to the unit.