Mitsubishi Electric PQHY-P72TYHMU-A Service Handbook page 280

[ IX Troubleshooting ]
1. Error Code
6607
No ACK error
2. Error definition and error detection method
The error is detected when no acknowledgement (ACK signal) is received after the transmission. (eg. When the data is trans-
mitted six times in a row with 30 seconds interval, the error is detected on the transmission side.)
The address/attribute appeared on the display on the remote controller indicates the controller which did not provide
the response (ACK).
3. System configuration
(2) Grouping of units in a system with multiple heat source units
Error
source Error display
address
LOSS- ME remote
NAY controller (RC)
(LC) MA remote
controller (MA)
HWE09080
Detection
method
No acknowl- (1) Factors (1) through (5) in the
edgement "Factors in system with one
(ACK) at IC heat source unit" (When per-
transmission to forming an interlocked opera-
LC tion of the LOSSNAY unit
and the indoor units that are
connected to different heat
source units.)
(2) Disconnection or short circuit
of the transmission line for
the heat source unit on the
terminal block for centralized
control line connection (TB7)
(3) When multiple heat source
units are connected and the
power source of one of the
heat source units has been
shut off.
(4) The male power supply con-
nector of the heat source unit
is not connected to the fe-
male power supply switch
connector (CN40).
(5) The male power supply con-
nectors on 2 or more heat
source units are connected to
the female power supply
switch connector (CN40) for
centralized control.
If an error occurs, after the
unit runs normally once, the
following causes may be con-
sidered.
ŒTotal capacity error
(7100)
ŒCapacity code error
(7101)
ŒError in the number of
connected units (7102)
ŒAddress setting error
(7105)
- 271 -
Cause Check method and remedy
1) Turn off the power source of
heat source unit for 5 or more
minutes, and turn it on again. If
the error is accidental, it will
run normally.If not, check the
cause 2).
2) Check the causes of (1) - (5). If
the cause is found, correct it. If
no cause is found, check 3).
3) Same cause as that for indoor
unit described in 3)
GB