
10 Troubleshooting
Troubleshooting in check mode
SMGB0091 rev.2 - 11/2015
261
10
10.3.3 Troubleshooting using the 7 segment display
Simple checking by 7-segment display
1
Turn ON indoor unit connected to
the RASC unit
During auto-addressing, the following items can be checked using the
RASC unit’s on-board 7-segment LED display:
1
Disconnection of power supply to the indoor unit.
2
Reverse connection of the operating line between the RASC and
indoor units.
3
Duplication of indoor unit number.
2
Turn ON the RASC unit
3
Auto-addressing starts
RASC unit, circuit board, PCB1
Checking method by 7-segment display
Operating conditions and each part of refrigeration cycle can be checked by 7-segment and push switches (PSW) on the
PCB in the RASC unit. During checking data, do not touch the electric parts except for the indicated switches because
220-240V is applied to them. Pay attention not to contact the tools with electrical parts. If contacted, electrical parts will
be damaged.
(*1): Contents of RASC micro-controller output status
8
8
Y52C
Y21
FAN1
YCH
PSH
FAN2
Y20F
Y20A
8
.
8
.
SEG1
PSW1 PSW2 PSW3
Manual
defrost
• To start checking, press PSW2 switch for more than three
seconds.
• To proceed checking, press the PSW2 switch.
• To back to the previous item, press the PSW3 switch.
• To cancel this checking, press the PSW2 switch for more than
3 seconds.
Check mode items
?
N O T E
For figures consisting of more than 2 digits, the upper 2 digits and lower 2 digits of the figures are indicated alternatively every 0.5 sec In
the 7-segments display, as shown below (the lower 2 digits are shown together with a dot at the lower right corner).
Example: 1253
12
53