Toshiba RAS-10YAV-E Service Manual page 27

8-2-1. Cooling Operation
(The Remote Controller MODE Button
is Set to the COOL Position)
• Once the setting is made, the operation mode is
memorized in the microcomputer so that the
same operation can be effected thereafter simply
by pushing [START/STOP] button.
• A cooling operation signal is transmitted to
outdoor unit.
• The indoor fan motor operates as shown in Fig.
8-2-1 when FAN button is set to AUTO.
• The motor operates with a constant air flow when
the FAN button is set to LOW, MED, or HIGH.
• The outdoor unit controls the outdoor fan relay
R01, R02 and R03, and the compressor motor
speed according to the operation command
signal sent from the indoor unit.
˚C
+3
+2,5
+2
+1,5
+1
+0,5
Set
0
temp.
–0,5
NOTE :
1: Calculated from difference in motor speed of
*
M+ and L–, and controlled.
Fig. 8-2-1 Setting of air flow [Fan AUTO]
(1) Cooling capacity control
• The cooling capacity and room temperature
are controlled by changing the compressor
motor speed according to both the difference
between the temperature detected by the
room temperature sensor and the temperature
set by TEMP button and also any change in
room temperature.
• When compressor has been activated or
reactivated, it operates with Max. 41 rps for 2
minutes, with Max. 91 rps from 2 minute to 3
minutes, and with Max. 94 rps after 3 minutes
passed.
• When room temperature is lower than set
temperature, indoor fan motor is operated at
fan speed L– as shown in Fig. 8-2-1 while the
outdoor unit stops.
(2) Prevent-freezing control
If temperature of indoor heat exchanger de-
tected by the indoor heat exchanger sensor is
5°C or lower, compressor motor speed is
gradually lowered to prevent freezing of the
M+
indoor heat exchanger. If temperature is 7°C or
*1
higher, return the operation to the above item
(1).
*1
(3) Current release control
*1
The input current of compressor and outdoor fan
L–
motor (Precisely inverter main circuit control
section) which occupy most of air conditioner
In normal
input is detected by the outdoor current sensor,
operation
and compressor motor speed is gradually
lowered so that current value does not exceed
9,0A if current value exceeds 9,0A. When the
current value lowers to 8,5A, return the opera-
tion to the above item (1).
9,0
8,5
(4) Outdoor temperature release control
The outdoor temperature release is controlled by
changing the current release points 9,0 and 8,5
in the above item according to temperature
detected by the outdoor temperature sensor.
For example, if the outdoor temperature is 43°C,
the value of current release point becomes 8,0A.
– 27 –
Comp. motor
speed down
Comp. motor
speed keep
Normal control
Fig. 8-2-2