Mitsubishi Electric CITY MULTI PUHY-400YMF-C Service Handbook page 172

Checking
code
6607 No ACK error
(continued)
System
Generating Display of
compo-
unit address trouble
sition
1
Outdoor Remote
unit (OC) control-
ler (RC)
2
Indoor Remote
unit (IC) control-
ler (RC)
2
3
Remote Remote
controller control-
(RC) ler (RC)
Meaning, detecting method
When no ACK signal is detected in 6 continuous times with 30 second
interval by transmission side controller, the transmission side detects error.
Note: The address/attribute shown on remote controller indicates the
controller not providing the answer (ACK).
Detecting
method
No reply As same that for single refrigerant system.
(ACK) at
OC
transmis-
sion to BC
No reply 1) Cause of 1) ~ 5) of "Cause for single refriger-
(ACK) at IC ant system".
transmis- 2) Disconnection or short circuit of transmission
sion to RC line of OC terminal block for centralized con-
trol (TB7).
3) Shut down of OC unit power source of one
re-frigerant system.
4) Neglecting insertion of OC unit power supply
connector (CN40).
5) Inserting more than 2 sets of power supply
connector (CN40) for centralized control use.
For generation after normal operation conduct-
ed once, the following causes can be consider-
ed.
• Total capacity error
• Capacity code setting error
• Connecting set number error
• Address setting error
6) The transmission booter is defective, has
disconnecitede wires, or the power has been
cut-off.
No reply 1) Cause of 1) ~ 3) of "Cause for single refri-
(ACK) at gerant system".
RC 2) Slipping off or short circuit of transmission line
transmis- of OC terminal block for centralized con-trol
sion to IC (TB7).
3) Shut down of OC unit power source of one
refrigerant system.
4) Neglecting insertion of OC unit power supply
connector (CN40).
5) Inserting more than 2 sets of power supply
connector(CN40) for centralized control use.
At generation after normal operation conducted
once, the following causes can be considered.
• Total capacity error
• Capacity code setting error
• Connecting set number error (7102)
• Address setting error
6) The transmission booster is defective, has dis-
connected wires, or the power has been cut-
off.
-169-
Cause
Same as measure for single refrigerant
system.
a) Shut down the power source of both
b) Check for 1) ~ 5) of causes. If cause
c) Check other remote controller or OC
(7100)
(7101)
(7102)
(7105)
a) Shut down the power source of OC
b) Check for 1) ~ 5) of causes. If cause
(7100)
(7101)
(7105)
Checking method & countermeasure
IC and OC for over 5 minutes simul-
taneously, and make them again.
Normal state will be returned incase
of accidental trouble.
is found, remedy it.
unit LED for troubleshooting for
trouble.
Trouble: Modify the trouble ac-
cording to the content
of check code.
No trouble: Faulty indoor con-
troller
for over 5 minute, and make it again.
Normal state will be returned in case
of accidental trouble.
is found, remedy it.
When normal state can not be ob-
tained, check 1) ~ 5) of causes.