Mitsubishi MXZ-8B140VA Technical & Service Manual page 27

Abnormal point and detection method
Check code
Faulty connection of LEV
For the connection of P100 indoor unit(s),
the connecting wire(s) must be connected
to the specified terminal block(s) in the
branch box.
Incorrect wiring
EE
(7130)
OCH480D
Case
1 Contact failure or miswiring of
indoor/outdoor unit connecting
wire
The connecting wire(s) from
P100 indoor unit(s) are not con-
nected to the specified terminal
block(s) in the branch box.
The connecting wire(s) from
P100 indoor unit(s) are con-
nected to an incorrect terminal
block(s) in the branch box.
2 Diameter or length of indoor–
branch box/branch box–out-
door unit connecting wire is out
of specified capacity.
3 Defective transmitting receiving
circuit of outdoor/branch box
controller circuit board
4 Defective transmitting receiv-
ing circuit of branch box/indoor
controller board
5 Defective branch box/indoor
power board
6 Noise has entered into power
supply or indoor–branch box/
branch box–outdoor unit con-
necting wire.
27
Judgment and action
1 Check disconnection or looseness or polar-
ity of indoor – branch box/branch box–outdoor
unit connecting wire of indoor and outdoor
units.
Before connecting P100 indoor unit(s), check
the requirements described in "9-2. WIRING
TO P100 INDOOR UNITS".
2 Check diameter and length of indoor–branch
box/branch box – outdoor unit connecting wire.
Total wiring length: 55 m (outdoor–branch box)
(including wiring connecting each branch box
unit and between branch box and outdoor
unit)
Also check if the connection order of flat
cable is S1, S2, S3.
If the error "EA" is detected, check the
number of the indoor units, the branch box
and P100 indoor unit(s) in the system.
3–5 Turn the power off once, and on again to
check.
Replace outdoor controller circuit board,
branch box controller board, indoor controller
board or indoor power 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.