Mitsubishi Electric City Multi PQHY-P72 Service Handbook page 251

[ IX Troubleshooting ]
(3) System connected to the system controllers (MELANS)
Error Code
6607 No ACK abnormality
(Contin-
ued)
Error
Error dis-
source ad-
play
dress
Heat M-NET re-
mote control-
source
ler (RC)
unit
System con-
(OC)
troller (SC)
MA remote
controller
(MA)
BC control-
M-NET re-
mote control-
ler (BC)
ler (RC)
system con-
troller (SC)
MA remote
controller
(MA)
Indoor M-NET re-
unit mote con-
(IC) troller (RC)
system
controller
(SC)
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 transmitted six times in a row with 30 seconds
interval, the error is detected on the transmission side.)
Note: The address/attribute appeared on the display on the remote controller
indicates the controller which did not provide the response (ACK).
Detection
Cause
method
No ac- Same cause as that for system with
knowl- one heat source unit
edgement
(ACK) at
BC trans-
mission to
OC
No ac- Same cause as that for system with
knowl- one heat source unit
edgement
(ACK) at IC
transmis-
sion to BC
Same as grouping of units in a sys-
No acknowl-
edgement
tem with multiple heat source units
(ACK) at RC
transmission
to IC
No ac- 1. Error occurrence on some IC
knowl- (1) Same cause as that for system
edgement with one heat source unit
(ACK) at
2. Error occurrence on all IC in the
SC trans-
system with one heat source unit
mission to
(1) Total capacity error (7100)
IC
(2) Capacity code error (7101)
(3) Error in the number of connected units
(7102)
(4) Address setting error (7105)
(5) Disconnection or short circuit of the
transmission line for the heat source
unit on the terminal block for central-
ized control line connection (TB7)
(6) Turn off the power source of the heat
source unit
(7) Malfunction of electrical system for the
heat source unit
3. Error occurrence on all IC
(1) Same causes as (1) - (7) described in
2.
(2) The male power supply connectors on
2 or more heat source units are con-
nected to the female power supply
switch connector (CN40) for the trans-
mission line for centralized control.
(3) Disconnection or shutdown of the pow-
er source of the power supply unit for
transmission line
(4) System controller (MELANS) malfunc-
tion
- 242 -
Check method and remedy
Same remedy as that for system with one
heat source unit
Same remedy as that for system with one
heat source unit
Same remedy as that for grouping of units in
a system with multiple heat source units
Same remedy as that for system with
one heat source unit
1) Check the LED display for troubleshoot-
ing on the heat source unit.
->If an error is found, check the check
code definition, and correct the error.
->If no error is found, check 2).
2) Check (5) - (7) on the left.
Check voltage of the transmission line for
centralized control.
20V or more : Check (1) and (2) on the
left.
Less than 20V : Check (3) on the left.