Capacity Control; Current Release Control - Toshiba RAS-18N3KVR-E Service Manual

Item
4. Capacity The cooling or heating capacity depending on the load is
control adjusted.
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 motor speed and rotor position
Correction value of Hz signal ≤ Operating Hz
5. Current This function prevents troubles on the electronic parts of the
release control compressor driving inverter.
This function also controls drive circuit of the compressor
speed so that electric power of the compressor drive circuit
does not exceed the specified value.
Outdoor unit inverter main
circuit control current
Operating current ≤ Setup value
Yes
Capacity control continues.
Outdoor temp.
45°C
40°C
44°C
16°C 39°C
11°C
15.5°C
10.5°C
Operation flow and applicable data, etc.
Ts –Ta
Correction of Hz signal
Detection of electromotive force
of compressor motor winding
Inverter output change
Commutation timing change
Change of compressor speed
Setup of current release point
No
Reduce compressor speed
Cooling current
release value
RAS-18N3AV-E RAS-22N3AV-E
7.05A
4.88A
6.15A 9.30A
10.50A
8.02A
Indoor unit
Room temp. (Ta)
Outdoor temp. To
Current decrease
Heating current
release value
RAS-18N3AV-E RAS-22N3AV-E
8.77A
10.88A
– –
31
FILE NO. SVM-12070
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 opera-
tion are same in cooling
operation and heating operation
1) The input current of the outdoor
unit is detected in the inverter
section of the outdoor unit.
2) According to the detected
outdoor temperature, the
specified value of the current is
selected.
3) Whether the current value
exceeds the specified value or
not is judged.
4) If the current value exceeds the
specified value, this function
reduces the compressor speed
and controls speed up to the
closest one commanded from the
indoor unit within the range which
does not exceed the specified
value.