Mitsubishi Electric PQHY-P72TYHMU-A Service Handbook page 285

[ 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
(3) System connected to the system controllers (MELANS)
Error
source Error display
address
System ME remote
controller controller
(SC) (RC)
MA remote
controller
(MA)
HWE09080
Detection
method
No acknowl- 1. Error display on some displays on
edgement ME remote controllers
(ACK) at IC
(1) Faulty wiring of the transmission
transmission to
line for ME remote controller
SC
(2) Disconnection or contact failure of
the transmission connector for ME
remote controller
(3) ME remote controller failure
2. Error occurrence on all IC in the
system with one heat source unit
(1) An error is found by the heat source
unit.
Total capacity error (7100)
Capacity code error (7101)
Error in the number of connected
units (7102)
Address setting error (7105)
(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) Turn off the power source of the
heat source unit
(4) Malfunction of electrical system for
the heat source unit
3. Error display on all displays on ME
remote controllers
(1) Same causes as (1) - (4) described
in 2.
(2) When the power supply unit for
transmission lines is used and the
male power supply connector is
connected to the female power sup-
ply switch connector (CN40) for the
transmission line for centralized
control
(3) Disconnection or shutdown of the
power source of the power supply
unit for transmission line
(4) System controller (MELANS) mal-
function
- 276 -
Cause Check method and remedy
Check (1) - (3) on the left.
1) Check the LED display for
troubleshooting on the heat
source unit.
2) Check (2) - (4) on the left.
Check (1) - (4) on the left
ΠIf an error is found, check
the check code definition,
and correct the error.
ŒIf no error is found, check
the cause 2)
GB