Mitsubishi Electric Mr.SLIM PUHZ-RP35VHA2 Service Manual page 51

Abnormal points and detection method
Error Code
Miswiring of indoor/outdoor unit con-
necting 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 and etc. after power is
turned on for 4 minutes.
2. Abnormal if outdoor controller circuit
board recognizes excessive number of
indoor units.
EA
(6844)
Miswiring of indoor/outdoor unit
connecting wire (converse wiring or dis-
connection)
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 con-
Eb
necting wire.
(6845)
Start-up time over
The unit cannot finish start-up process
within 4 minutes after power on.
EC
(6846)
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 out-
door 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/
outdoor 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
supply or indoor/outdoor unit
connecting wire.
51
Judgment and action
1 Check disconnection or looseness or polar-
ity 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: 80m
(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 one outdoor unit. (If EA is
detected)
4~6 Turn 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.
w The descriptions above, 1-8, are for EA, Eb
and EC.