–81–
(6)
Trouble and remedy of remote controller
(In the case of MA remote controller)
Symptom
Cause
Check method and Remedy
1
2
If the controller does
not beep when the
buttons are pressed,
if the monitor is off,
or no operation is
possible.
(An appropriate
display on the
remote control is not
on.)
When turning on the
remote control
operation SW, a
temporary operation
display is indicated,
and the display lights
out immediately, and
the unit stops.
1) Power supply from transformers to the indoor unit is
not turned on.
1
The original power supply of Indoor Unit is not
turned on.
2
Disconnected connector (CND, CNT, CN3T) on
the controller board in the room.
3
Blown fuse on the control board in the indoor unit.
4
Transformer defects or damage to unit.
2) MA remote controller has been wired incorrectly.
1
The MA remote controller line has been broken,
and the connection to the terminals has been
disconnected.
2
Short circuit of the MA remote control wiring
3
Reversed connections of the wiring on remote
controller.
4
Incorrect connection of the MA remote control wiring
to the transmission line terminal block (TB 5).
5
Reversed connections between the MA remote
control wiring in the indoor unit and AC 200V
power supply wiring.
6
Reversed connection between the MA remote
control wiring in the indoor unit and M-NET
transmission wiring.
3) The maximum number of MA remote controllers
connected to a unit exceeds two.
4) The length and diameter of the MA remote line do
not meet the specifications.
5) The wiring of the remote display output to the
outdoor unit is short circuited, or the relay is
connected with reversed polarity.
6) Defective of the controller board in the room
7) Defects of MA remote control
1) M-NET transmission power supply from the outdoor unit is not
supplied.
1
The original power supply of the outdoor unit is not turned on.
2
Disconnection of connectors on the board of the outdoor unit.
Main board --- CNS1, CNVCC3
INV board --- CNAC2, CNVCC1, CNL2
3
Problems with the power supply circuit of the outdoor unit.
●
INV board defects
●
Blown fuse (F1 on INV Board)
●
Diode stack destruction
●
Prevention resistance of rush current (R1) damage
2) Shorted transmission line.
3) Wiring error in the M-NET transmission line on the outdoor unit
side.
1
Broken transmission line and disconnected terminal block.
2
The room transmission line is wired to the transmission line
terminal block (TB7) for the central control by mistake.
4) M-NET transmission line break on the side of the room unit
5) Broken wires between the M-NET transmission terminal block
(TB5) and the room controller board CN2M and dislocated
connectors.
a) Check the MA remote control terminal
voltage (between A and B).
i) In the case of voltage between DC 8.5
and 12V, and there is a problem with
the remote controller
ii) In the case of the absence of voltage
●
Check items 1) and 3) on the left.
If these turn out to be the factors,
then modifications should be made.
●
If item 1) or 3) is not found to be the
cause of the problem, proceed to b).
b) Remove the remote control wiring from
the terminal block TB13 for the MA
remote control in the indoor unit, and
check voltage between A and B.
i) In the case of voltage between DC9
and 12V.
Check the left described 2) and 4), if
these are factors, then modifications
should be performed.
ii) In the case of the absence of voltage
●
Recheck item 1). If problems are found,
then modifications should be made.
●
If no problems are found with items listed
under 1) on the left, check the wiring for
the remote display (the relay polarity, etc.)
●
If no problems are found, replace the
controller board in the indoor unit.
NO
NO
YES
YES
NO
YES
YES
Check 2) and 3) under
the cause column.
Correct the problem
Is error code 7120 displayed?
Check item 1) above.
Check item 4).
Is it between
9 and 12V?
Check item 5).
Defects in the indoor
unit controller board or
MA remote control
Factors available?
Correct the problem
Terminal block (TB15)
voltage check for the
transmission line of the
indoor unit
NO
The same symptoms
appear in all units in the same
refrigerant system?
Check the self-
diagnosis LED
Check method and handling
In the case of item 1), the
LED 1 on the controller
board in the unit is off.
In the case of factors 2) and
3) Indicated by 7102 error
code on the self-diagnosis
LED of the outdoor unit.