Mitsubishi Electronics OC366 Air Conditioner User Manual


 
49
6607
No ACK (Acknowledgement)
Abnormality which controller of the
sending side detects when there is no
answer (ACK) from other side though data
was transmitted once. It is detected 6
times every 30seconds continuously.
Factor that does not related to origin
Turn off power supply of outdoor unit,
indoor unit fresh master and lossnay
for 2 minutes or more at the same
time. Then, turn on power supply. It
recovers normally at the malfunction
that happens by chance.
Note) Address/Attribute displayed on the
remote controller shows the controller,
which did not send back replay (ACK).
Since the address switch was changed
with the current passed, the unit in the
last address does not exist.
Check the address switch in the
address, which occurs abnormality.
Decline of transmission voltage and
signal by transmission line tolerance
over
Check whether the transmission line
is connected / loosen or not at origin.
(Terminal board or connector)
· The furthest point···200m
Check whether the transmission line
tolerance is over or not.
· Remote controller line···(12m)
(Refer to 8-3.)
Check whether the kind of
transmission line is mistaken or not.
Decline of transmission line voltage
and signal by unmatched kind of line.
When there is any trouble from above
-, turn off power supply of outdoor
unit, indoor unit and lossnay for 2
minutes or more at the same time.
Then, turn on power supply.
· Shield line-CVVS,CPEVS
When there is not any trouble in
single refrigerant system (1 outdoor
unit) from above -, controller
defective in displayed address and
attribute.
When there is not any trouble in
different refrigerant system (2 outdoor
unit or more) from above -,
determine it after .
When the address, which should not
exist, is an origin, since there is the
indoor unit which memorizes the
address data, cancel the unnecessary
address data by the manual setting
function of remote controller.
Line diameter···1.25 Aor more
However, they are limited to the
system, which sets the group between
different refrigerant systems, or which
fresh master /lossnay are connected.
Decline of transmission line voltage
and signal by a number of
over-connected units.
When there is not any trouble from
above -, replace the displayed
address/attribute controller board.
Miss operation of origin controller,
which happens by chance.
In this time, when the error does not
recover to normal, the outdoor unit
multi controller board (repeater circuit)
defective is expected.
Original controller defective
When the cause of displayed address and
attribute is on the outdoor unit side.
Contact failure of outdoor unit or
indoor unit transmission line
(The indoor unit detects when there is no
reply (ACK) on transmitting from the
indoor unit to the outdoor unit.)
Indoor unit transmission connector
(CN2M) disconnection
Sending/receiving signal circuit failure
in the indoor/outdoor unit
When the cause of displayed address and
attribute is on the indoor unit side.
When operating with multi refrigerant
system indoor units, the remote
controller transmits the signal to the
indoor unit after the other refrigerant
system outdoor unit is turned off or
turned on again in 2 minutes, and
detects abnormality.
(The remote controller detects when there
is no reply (ACK) on transmitting from the
remote controller to the indoor unit.)
Contact failure of remote controller or
indoor unit transmission line.
Indoor unit transmission connector
(CN2M) disconnection.
Check the recovery by replacing the
multi controller board one by one.
Sending/receiving signal circuit failure
in the indoor unit or remote controller.
Display
Abnormal point and detecting method
Causes
Check points
Continued on the next page.