Mitsubishi Electric PUMY-P125VMA1 Technical & Service Manual page 52

Display
Meaning and detecting method
No ACK (Acknowledgement)
6607
Abnormality which controller of the
1
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.
Note) Address/Attribute displayed on the
remote controller shows the controller,
which did not send back replay (ACK).
1) When the cause of displayed address
and attribute is on the outdoor unit side
(The indoor unit detects when there is no
reply (ACK) on transmitting from the
indoor unit to the outdoor unit.)
2) When the cause of displayed address
and attribute is on the indoor unit side
(The remote controller detects when
there is no reply (ACK) on transmitting
from the remote controller to the indoor
unit.)
Causes
Factor that not related to origin
1) Since the address switch was
changed with the current passed, the
unit in the last address does not exist.
2) Decline of transmission voltage and
signal by transmission line tolerance
over
· The furthest point···200m
· Remote controller line···(12m) (See
page 26-33 for details)
3) Decline of transmission line voltage
and signal by unmatched kind of line.
Kind···Shield line-CVVS,CPEVS
No shield···VCTF, VCTFK,
CVV, CVS, VVR, VVF, VCT
Line diameter···1.25 e or more
4) Decline of transmission line voltage
and signal by a number of over-
connected units.
5) Miss operation of origin controller,
which happens by chance.
6) Origin controller defective
1) Contact failure of outdoor unit or
indoor unit transmission line
2) Indoor unit transmission connector
(CN2M) disconnection
3) Sending/receiving signal circuit
failure in the indoor/outdoor unit
1) 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
2minutes, and detects abnormality.
2) Contact failure of remote controller
or indoor unit transmission line.
3) Indoor unit transmission connector
(CN2M) disconnection.
4) Sending/receiving signal circuit
failure in the indoor unit or remote
controller.
52
Check points
1
Turn off power supply of outdoor unit,
indoor unit fresh master and lossnay
for 2minutes or more at the same
time. Then, turn on power supply. It
recovers normally at the malfunction
that happens by chance.
2
Check the address switch in the
address, which occurs abnormality.
3
Check whether the transmission line
is connected / loosen or not at origin.
(Terminal board or connector)
4
Check whether the transmission line
tolerance is over or not.
5
Check whether the kind of
transmission line is mistaken or not.
When there is any trouble from above
1-5, turn off power supply of outdoor
unit, indoor unit and lossnay for
2minutes or more at the same time.
Then, turn on power supply.
When there is not any trouble in
single refrigerant system (1outdoor
unit) from above1-5, controller
defective in displayed address and
attribute.
When there is not any trouble in
different refrigerant system (2outdoor
unit or more) from above1-5,
determine it after 6.
6
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.
However, they are limited to the
system, which sets the group between
different refrigerant systems, or which
fresh master /lossnay are connected.
When there is not any trouble from
above 1-6, replace the displayed
address/attribute controller board.
In this time, when the error does not
recover to normal, the outdoor unit
multi controller board (repeater circuit)
defective is expected.
Check the recovery by replacing the
multi controller board one by one.