46
<M-NET communication error>
Note: “Indoor unit” in the text indicates M-NET board in outdoor unit.
Check Code Abnormal points and detection method
Case
Judgment and action
A0
(6600)
Address duplicate definition
This error is displayed when transmission
from the units of same address is detected.
Note: The address and attribute displayed
at remote controller indicate the
controller that detected abnormality.
1
There are 2 or more same address of
controller of outdoor unit, indoor unit,
FRESH MASTER, or LOSSNAY.
2
Noise has entered into transmission
signal and signal was transformed.
Search the unit with same address
as abnormality occurred. If the same
address is found, shut the power supply
of outdoor unit and indoor unit and
FRESH MASTER or LOSSNAY at the
same time for 2 minutes or more after the
address is corrected, and turn the power
on again.
Check transmission waveform or noise
on transmission wire.
A2
(6602)
Hard ware error of transmission
processor
Transmission processor intended to transmit
“0”, but “1” appeared on transmission wire.
Note: The address and attribute display
at remote controller indicate the
controller that detected abnormality.
1
Error is detected if waveform is
transformed when wiring works of
transmission wire of outdoor unit, indoor
unit, FRESH MASTER or LOSSNAY
are done, or polarity is changed with
the power on and transmission data
collide each other.
2
Defective transmitting receiving circuit
of transmission processor
3
Transmission data is changed by the
noise on transmission.
1
If the works of transmission wire is
done with the power on, shut 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.
2
Check transmission waveform or noise
on transmission wire.
A3
(6603)
BUS BUSY
1. Overtime error by collision damage
Abnormal if transmitting is not possible
for 8–10 minutes continuously because
of collision of transmission.
2. Data could not reach transmission wire
for 8–10 minutes continuously because
of noise, etc.
Note: The address and attribute displayed
at remote controller indicate the
controller that detected abnormality.
1
Transmission processor could not
transmit signal because short cycle
voltage of noise and the like have
entered into transmission wire
continuously.
2
Transmission quantity has increased
and transmission is not possible
because there was wiring mistake of
terminal block for transmission wire
(TB3) and terminal block for central
control (TB7) in outdoor unit.
3
Transmission are mixed with others
and occupation rate on transmission
wire rose because of defective
repeater (a function to connector or
disconnect transmission of control and
central control system) of outdoor unit,
then abnormality is detected.
1
Check if transmission wire of indoor
unit, FRESH MASTER, LOSSNAY, or
remote controller is not connected to
terminal block for central control (TB7)
of outdoor unit.
2
Check if transmission wire of indoor
unit, FRESH MASTER or LOSSNAY
is not connected to terminal block for
transmission wire of outdoor unit.
3
Check if terminal block for transmission
wire (TB3) and terminal block for
central control (TB7) is not connected.
4
Check transmission waveform or noise
on transmission wire.
A6
(6606)
Communication error with
communication processor
Defective communication between unit
processor and transmission processor
Note: The address and attribute display
at remote controller indicate the
controller that detected abnormality.
1
Data of transmission processor or unit
processor is not transmitted normally
because of accidental trouble such as
noise or thunder surge.
2
Address forwarding from unit
processor is not transmitted normally
because of defective transmission
processor hardware.
Turn off the power supply of outdoor
unit, indoor unit and FRESH MASTER
or LOSSNAY at the same time for 2
minutes or more, and turn the power
on again. System returns normally if
abnormality was accidental malfunction.
If the same abnormality generates again,
abnormality-generated controller may be
defective.
Check Code Abnormal points and detection method
Case
Judgment and action
PL
Abnormal refrigerant circuit
During Cooling, Dry, or Auto Cooling
operation, the following conditions are
regarded as failures when detected for 1
second.
a) The compressor continues to run for 30
or more seconds.
b) The liquid pipe temperature or the
condenser/evaporator temperature is
75°C or more.
These detected errors will not be
cancelled until the power source is
reset.
1
Abnormal operation of 4-way valve
2
Disconnection of or leakage in
refrigerant pipes
3
Air into refrigerant piping
4
Abnormal operation (no rotation) of
indoor fan
• Defective fan motor.
• Defective indoor control board.
5
Defective refrigerant circuit (clogging)
1
When this error occurs, be sure to
replace the 4-way valve.
2
Check refrigerant pipes for disconnection
or leakage.
3
After the recovery of refrigerant, vacuum
dry the whole refrigerant circuit.
4
Refer to "10-6. HOW TO CHECK THE
PARTS".
5
Check refrigerant circuit for operation.
To avoid entry of moisture or air into
refrigerant circuit which could cause
abnormal high pressure, purge air in
refrigerant circuit or replace refrigerant.
OCH653
