Capacity Control; Release Protective Control By Temperature Of Indoor Heat Exchanger - Toshiba RAS-M05G3KVSG-E Service Manual

Item
The cooling capacity depending on the load is adjusted.
3. Capacity
control
According to difference between the setup value of tempera-
ture and the room temperature, the capacity is adjusted by
the compressor revolution.
Remote controller
Set temp. (Ts)
Detection of electromotive force
Detection of motor speed and rotor position
Correction value of Hz signal ≤ Operating Hz
4. Release
<In cooling/dry operation>
protective (Prevent-freezing control for indoor heat exchanger)
control by
In cooling/dry operation, the sensor of indoor heat
temperature
exchanger detects evaporation temperature and
of indoor
controls the compressor speed so that temperature of
heat exchanger
the heat exchanger does not exceed the specified
value.
7 C
6 C
5 C
Reduction of compressor speed
Operation flow and applicable data, etc.
Ts –Ta
Correction of Hz signal
of compressor motor winding
Inverter output change
Commutation timing change
Change of compressor speed
Usual cooling capacity control
Indoor unit
Room temp. (Ta)
R
When the value is
in Q zone, the
Q
compressor speed
is kept.
P
- 25 -
Description
1) The difference between set
temperature on remote controller
(Ts) and room temperature (Ta)
is calculated.
2) According to the temperature
difference, the correction value of
Hz signal which determines the
compressor speed is set up.
3) The rotating position and speed
of the motor are detected by the
electromotive force occurred on
the motor winding with operation
of the compressor.
4) According to the difference
resulted from comparison of the
correction value of Hz signal with
the present operation Hz, the
inverter output and the commuta-
tion timing are varied.
5) Change the compressor motor
speed by outputting power to the
compressor.
* The contents of control
operation are same in cooling
operation.
1) When temperature of the indoor
heat exchanger drops below 5°C,
the compressor speed is
reduced. (P zone)
2) When temperature of the indoor
heat exchanger rises in
the range from 6°C to under 7°C,
the compressor speed is kept.
(Q zone)
3) When temperature of the indoor
heat exchanger rises to 7°C or
higher, the capacity control
operation returns to the usual
control in cooling operation.
(R zone)