Toshiba RAS-10YAV-E Service Manual page 30

8-2-3. Heating Operation
Transferring of heating operation signal from indoor
unit to outdoor unit starts.
The indoor fan motor operates by the room tempera-
ture when selecting "AUTO" of "FAN" as shown in
Fig. 8-2-6, and operates with a set air flow when
selecting "Low" to "High".
However, to prevent cold draft, revolution speed of
the fan is restricted by indoor heat exchanger when
air flow is AUTO (Fig. 8-2-7) and starting of FAN
Manual.
[Basic control]
Set
0
temp.
–0,5
–1
–1,5
–2
–5,0
–5,5
[FAN AUTO]
*1, *2 : Approximate revolution speed of M+ and L to
linear according to temperature.
Fig. 8-2-6 Setting of air flow
[Cold draft preventing control]
The upper limit of fan revolution speed is shown
below.
44 33
43 32
31 20
30 19
2
*
A + 4 A
A – 8 A – 8
Starting
FAN
of FAN
AUTO
Manual
Fig. 8-2-7 Cold draft preventing control
NOTES :
(1) Stops for 2 minutes after thermostat-OFF.
(2) 24°C when the set temp. is 24°C or more
Set temp. when the set temp. is below 24°C
(3) SUL : Super ultra low
[In starting and in stability]
FAN
AUTO
FAN
Manual
LOW
The outdoor unit controls the outdoor fan based
* 1
* 2
upon the operation signal sent from the indoor unit,
and also controls revolution speed of the compres-
sor motor.
M+
The power coupler (IC20) for four-way valve is
turned on, and turned off in defrost operation.
(1) Heating capacity control
HIGH
(2) High-temp. release control
HIGH
Approximate
revolution speed
of HIGH and SUL
linear by Tc.
3
*
SUL (3) Current release control
SUL ( NOTE : 1)
*
Stop
– 30 –
In starting
• Until 12 minutes
passed after
operation start
• When 12 to 25
minutes passed
after operation start
and room temp. is
3°C or lower than
set temp.
• Room temp. < Set
temp. –4°C
Calculate the difference between temperature
detected by room temp. sensor every minute and
the set temp. set on "Temp. indicator" and
variation amount of room temp.
Then, obtain the correction amount of the
command signal, and correct the current fre-
quency command signal.
If temperature of the indoor heat exchanger
detected by the indoor heat exchanger sensor is
55°C or higher, compressor motor speed is
gradually lowered to prevent over-temp. rising of
compressed pressure.
If temperature becomes below 48°C, return to
above item (1).
The input current of compressor and outdoor fan
motor (Precisely inverter main circuit control
section) which occupy most of air conditioner
input is detected by the outdoor current sensor.
The compressor motor speed is lowered gradu-
ally according to the range of TO (outside air
temp.) if the input current exceeds the current
value determined in each zone as shown in Fig.
8-2-8 so that the input current does not exceed
the set value.
In case that the current lowered by approx. 0,5A
than each set value, return to above item (1).
In stability
• When 12 to 25
minutes passed
after operation start
and room temp. is
higher than (set
temp. –3°C)
• When 25 minutes or
more passed after
operation start
• Room temp. ≥ Set
temp. –3,5°C