5 Control system
Standard operation sequence
SMGB0091 rev.2 - 11/2015
80
5.3 Standard operation sequence
5.3.1 Cooling operation
Temperature
on the top of
compressor
Power to
R.U: ON
Power to CH : ON
Power to CH : OFF
I.U:
Indoor unit
R.U:
RASC unit
> 80 ºC
Power to I.U:
ON
Power to PCB in
I.U.: ON
Start of transmission between I.U
and R.U
Start of transmission between I.U
and remote control switch
Auto-louver 0 reset
Power to YH2 in
I.U.: OFF
FS
MD : ON
< 75 ºC
OFF
(Higher than activation level)
ON
(Lower than activation level)
(for unit with drain pump)
Setting at
COOL
COOL indication
Set temperature
indicated
Pressing
TEMP switch
Switch: increasing set temperature
Switch: decreasing set temperature
Pressing
RUN/STOP
switch
Run LED: ON,
RUN is indicated
Power to PCB in
R.U: ON
Power to YH2 in
I.U: ON
Pressing
FAN switch
Air
flow
change over
switch
HIGH indication
MEDIUM indication
LOW indication
Power to YH2 for
20 sec.
Operation at set
indoor fan speed
MD : ON
for unit with drain pump
Power to EHW: ON
for unit with EHW
A
IU
air
intake temp.
COOLING
operation
to 1
Power to MOF
Power to
Y52C: ON
1 sec.
Power to YH2 in
I.U PCB: OFF
Lower than set
temperature
Higher than set
temperature
+2 ºC
Outdoor
temp.
< -5ºC
≥ -5ºC
Power to
CMC: ON
No
Yes
Power to MC
MD: ON
(for unit with drain pump)
IU: Indoor unit
RU: RASC unit
?
N O T E
YH2 in IU’s PCB
Y52C in RASC PCB1
Continues in the next page.