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A6
(6606)
Communication error with communica-
tion processor
Defective communication between unit
processor and transmission processor
Note) The address and attribute display at
remote controller indicate the con-
troller that detected abnormality.
1
Data of transmission proces-
sor or unit processor is not
transmitted normally because
of accidental trouble such as
noise or lightning surge.
2
Address forwarding from unit
processor is not transmitted
normally because of defective
transmission processor hard-
ware.
Turn off the power supply of outdoor unit and
indoor unit and FRESH MASTER or LOSSNAY
at the same time for 2 minutes or more, and
turn the power on again. System returns to
normal if abnormality was accidental malfunc-
tion. If the same abnormality generates again,
abnormality-generated controller may be defec-
tive.
Error Code
Abnormal point and detection method
Case
Judgment and action
A7
(6607)
NO ACK signal
1. Transmitting side controller detects
abnormal if a massage was transmitted
but there is no reply (ACK) that a mes-
sage was received. Transmitting side
detects abnormality every 30 seconds, 6
times continuously.
Note) The address and attribute displayed
at remote controller is indicate the
controller that did not reply (ACK).
Common factor that has no rela-
tion with abnormality source.
1
The unit of former address
does not exist as address
switch has changed while the
unit was energized.
2
Extinction of transmission wire
voltage and signal is caused by
over-range transmission wire.
• Maximum distance ······ 200m
[656ft]
• Remote controller line .. (12m
[39ft])
3
Extinction of transmission wire
voltage and signal is caused by
type-unmatched transmission
wire.
Type······
With shield wire-
CVVS,
CPEVS
With normal wire (no shield)-
VCTF,
VCTFK,
CVV
CVS, VVR, VVF, VCT
Diameter ····1.25mm
2
[AWG16]
or more
4
Extinction of transmission wire
voltage and signal is caused
by over-numbered units.
5
Accidental malfunction of
abnormality-detected controller
(noise, lightning surge)
6
Defective of abnormality gen-
erated controller
2. If displayed address or attribute is out-
door unit, Indoor unit detects abnormality
when indoor unit transmitted to outdoor
unit and there was no reply (ACK).
1
Contact failure of transmission
wire of outdoor unit or indoor
unit
2
Disconnection of transmission
connector (CN2M) of outdoor
unit
3
Defective transmitting receiving
circuit of outdoor unit or indoor
unit
Always try the followings when the error
“A7” occurs.
1
Turn off the power supply of outdoor unit
and indoor unit and FRESH MASTER or
LOSSNAY at the same time for 2 minutes or
more, and turn the power on again. If mal-
function was accidental, the unit returns to
normal.
2
Check address switch of abnormality gener-
ated address.
3
Check disconnection or looseness of abnor-
mality generated or abnormality detected
transmission wire (terminal block and con-
nector)
4
Check if tolerance range of transmission wire
is not exceeded.
5
Check if type of transmission wire is correct
or not.
If there were some troubles of
1
-
5
above,
repair the defective, then turn off the power
supply of outdoor unit and indoor unit and
FRESH MASTER or LOSSNAY at the same
time for 2 minutes or more, and turn the power
on again.
• If there was no trouble with
1
-
5
above in
single refrigerant system (one outdoor unit),
controller of displayed address or attribute is
defective.
• If there was no trouble with
1
-
5
above in dif-
ferent refrigerant system (2 or more outdoor
units), judge with
6
.
6
If address of abnormality source is the
address that should not exist, there is the
unit that memorizes nonexistent address
information. Delete useless address informa-
tion with manual setting function of remote
controller.
Only the system FRESH MASTER or
LOSSNAY are connected to, or the system
that is equipped with group setting of differ-
ent refrigerant system.
If there was no trouble with
1
-
6
above, replace
the controller board of displayed address or
attribute.
If the unit does not return to normal, multi-con-
troller board of outdoor unit may be defective
(repeater circuit).
Replace multi-controller board one by one to
check if the unit returns to normal.
3. If displayed address or attribute is indoor
unit, remote controller detects abnormal-
ity when remote controller transmitted to
indoor unit and there was no reply (ACK).
1
During group operation with
indoor unit of multi- refrigerant
system, if remote controller
transmit to indoor unit while
outdoor unit power supply
of one refrigerant system is
turned off or within 2 min-
utes of restart, abnormality is
detected.
2
Contact failure of transmission
wire of remote controller or
indoor unit
3
Disconnection of transmission
connector (CN2M) of indoor
unit
4
Defective transmitting receiving
circuit of indoor unit or remote
controller
