– 28 –
(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. 33 rps for 2
minute, with Max. 57 rps from 2 to 4 minutes,
with Max. 91 rps from 4 to 7 minutes, and with
Max. 92 rps after 7 minutes passed.
• When room temperature is lower than set
temperature, indoor fan motor is operated at
fan speed L– as shown in Fig. 8-2-2 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
indoor heat exchanger. If temperature is 7°C or
higher, return the operation to the above item (1).
(3) Current release control
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,
and compressor motor speed is gradually
lowered so that current value does not exceed
1
1A if current value exceeds 11A. When the
current value lowers to 12A, return the operation
to the above item (1).
Normal control
Current value (A)
Comp. motor
speed down
Comp. motor
speed keep
I1
I2
Fig. 8-2-3
Table 8-2-1
Current value Current limit
11 9.5
12 9,0
(4) Outdoor temperature release control
The outdoor temperature release is controlled by
changing the current release points 1
1 and 12 in
the above item according to temperature de-
tected by the outdoor temperature sensor.
For example, if the outdoor temperature is over
40°C, the value of current release point be-
comes 7,7A.
(5) Limit for maximum compressor motor speed
by indoor fan speed
When outdoor temperature sensor detected
32°C or lower, and indoor heat exchanger
sensor detected 17°C or lower, the maximum
compressor motor speed is limited by the indoor
fan speed.
For example, when 1 unit only operates, the
compressor motor speed is limited as described
in the table below.
Table 8-2-2
Air flow M10UKCV-E M13UKCV-E M16UKCV-E
rate (rps) (rps) (rps)
HIGH 45 72 77
M+ 42 59 66
MED. 34 40 54
L–, L 31 31 43
UL, SUL 31 31 31
(6) Louver control
The vertical air flow louvers are automatically set
to horizontal or cool memory position.
When temperature of indoor heat exchanger
becomes 5°C or lower by the prevent-freezing
control and the compressor is turned off, the
vertical air flow louvers close once and then
return to the position of previous time.
(7) Discharge temperature control
The discharge temperature of refrigerant gas
from the compressor is detected by the dis-
charge temperature sensor, and controls operat-
ing compressor motor speed.
1) Control 1 (A zone) : Normal operation zone
When TD detect value is 101°C or lower, the
operation is performed with operating motor
speed instructed by the serial signal.
2) Control 2 (B zone) : Slow-up zone of motor
speed
When TD detect value is 101°C or higher,
operating motor speed is slowly up.
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