Service manual

13-4
TROUBLESHOOTING
SM DNGDCI 2-E.1 GB
13.1.4 Indoor Unit Diagnostics
No Problem 5 4 3 2 1
1 RT-1 is disconnected 0 0 0 0 1
2 RT-1 is shorted 0 0 0 1 0
3 RT-2 is disconnected 0 0 0 1 1
4 RT-2 is shorted 0 0 1 0 0
5 Reserved 0 0 1 0 1
7 Communication mismatch 0 0 1 1 1
8 No Communication 0 1 0 0 0
9 No Encoder 0 1 0 0 1
10 Reserved 0 1 0 1 0
11 Outdoor Unit Fault 0 1 0 1 1
… Reserved
17 Defrost protection 1 0 0 0 1
18 Deicing Protection 1 0 0 1 0
19 Outdoor Unit Protection 1 0 0 1 1
20 Indoor Coil HP Protection 1 0 1 0 0
21 Overflow Protection 1 0 1 0 1
22 Reserved
24 EEPROM Not Updated 1 1 0 0 0
25 Bad EEPROM 1 1 0 0 1
26 Bad Communication 1 1 0 1 0
27 Using EEPROM data 1 1 0 1 1
28 Model A 1 1 1 0 0
29 Model B 1 1 1 0 1
30 Model C 1 1 1 1 0
31 Model D 1 1 1 1 1
13.1.4.1 Indoor Unit Diagnostics and Corrective Actions
No. Fault Probable Cause Corrective Action
1
Sensor failures of
all types
Check sensor connections or
replace sensor
2
Communication
mismatch
Indoor and Outdoor
controllers are with
different versions
Replace Indoor controller
3 No Communication
Communication or
grounding wiring is not
good.
Check Indoor to Outdoor
wiring and grounding
4 No Encoder Indoor electronics or motor
Check motor wiring, if ok,
replace motor, if still not ok,
replace Indoor controller.
5 Outdoor Unit Fault Outdoor controller problem
Switch to Outdoor
diagnostics.
6
EEPROM Not
Updated
System is using ROM
parameters and not
EEPROM parameters
No action, unless special
parameters are required for
unit operation.
7 Bad EEPROM
No action, unless special
parameters are required for
unit operation.
8
Bad
Communication
Communication quality is
low reliability
Check Indoor to Outdoor
wiring and grounding
9
Using EEPROM
data
No problem. System is
using EEPRRRROM
parameters
CONTENT