Mitsubishi Electric CMB-PW202V-J, Service Handbook, Page: 86 / 114

[
VIII
Troubleshooting ]
- 77 -
HWE09070 GB
1. Error Code
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)
6607
Error
source
address
Error display
Detection
method
Cause Check method and remedy
Indoor
unit
(IC)
ME remote
controller (RC)
MA remote
controller (MA)
No acknowl-
edgement
(ACK) at RC
transmis-
sion to IC
Same as grouping of units in a system
with multiple outdoor units
Same remedy as that for
grouping of units in a sys-
tem with multiple outdoor
units
System control-
ler (SC)
No acknowl-
edgement
(ACK) at SC
transmis-
sion to IC
1. Error occurrence on some IC Same remedy as that for
system with one outdoor
unit
(1) Same cause as that for system with one
outdoor unit
2. Error occurrence on all IC in the system
with one outdoor unit
1) Check the LED display
for troubleshooting on the
outdoor unit.
(1) Total capacity error (7100)
Œ
If an error is found,
check the check code
definition, and correct
the error.
ΠIf no error is found,
check 2).
(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 trans-
mission line for the outdoor unit on the ter-
minal block for centralized control line
connection (TB7)
2) Check (5) - (7) on the left.
(6) Turn off the power source of the outdoor
unit
(7) Malfunction of electrical system for the
outdoor unit
3. Error occurrence on all IC Check voltage of the
transmission line for cen-
tralized control.
Π20V or more: Check (1)
and (2) on the left.
ΠLess than 20V: Check
(3) on the left.
(1) Same causes as (1) - (7) described in 2.
(2) The male power supply connectors on 2
or more outdoor units are connected to
the female power supply switch connector
(CN40) for the transmission line for cen-
tralized control.
(3) Disconnection or shutdown of the power
source of the power supply unit for trans-
mission line
(4) System controller (MELANS) malfunction