Operation Description; Outline Of Air Conditioner Control - Toshiba RAS-18UFHP-E4 Service Manual

7-1. Outline of Air Conditioner Control

This is a fixed capacity type air conditioner, which uses
a AC motor for an indoor fan. The AC motor drive
circuit is mounted in the indoor unit. And electrical
parts which operate the compressor and the outdoor
fan motor, are mounted in the outdoor unit.
The air conditioner is mainly controlled by the indoor
unit controller. The controller operates the indoor fan
motor based upon commands transmitted by the
remote control and transfers the operation commands
to the outdoor unit controller.
The outdoor unit controller receives operation
commands from the indoor unit, and operates the
outdoor fan motor and the compressor.
(1) Role of indoor unit controller
The indoor unit controller receives the operation
commands from the remote control and executes
them.
• Temperature measurement at the air inlet of the
indoor heat exchanger by the indoor
temperature sensor
• Temperature setting of the indoor heat
exchanger by the heat exchanger sensor
• Louver motor control
• Indoor fan motor operation control
• LED display control
• Transferring of operation commands to the
outdoor unit
• Receiving of information of the operation status
and judging of the information or indication of
error
(2) Role of outdoor unit controller
The outdoor unit controller receives the operation
commands from the indoor controller and
executes them.
• Compressor operation
control
• Operation control of
outdoor fan motor
OPERATION
MODE
RAS-18UFHP Series
RAS-18UFP Series
RAS-24UFHP Series
RAS-24UFP Series

7. OPERATION DESCRIPTION

Operations according
to the commands
from the indoor unit
Table 7-1-1
Cooling
Heat
UH
Fan only
Dry
rpm
1120
Air flow volume (m /h)
3
830
rpm
−
Air flow v olume (m /h) −
3
rpm
1210
Air flow volume (m /h)
3
930
rpm
−
Air flow volume (m /h) −
3
• Turning off the compressor and outdoor fan
when the outdoor unit receives the shutdown
command
• Defrost control in heating operation
(Temperature measurement by the outdoor heat
exchanger and control for the four-way valve
and the outdoor fan motor) *Heat pump Model
only
7-1-1. Louver control
(1) Vertical air flow louver
Position of veritcal air flow louver is automatically
controlled according to the operation mode.
Besides, position of vertical air flow louver can be
arbitrarily set by pressing [FIX] button.
The louver position which is set by [FIX] button is
stored in the microcomputer, and the louver is
automatically set at the stored position for the next
operation.
(2) Swing
If [SWING] button is pressed when the indoor unit
is in operation, the vertical air flow louver starts
swinging. When [FIX] button is pressed, it stops
swinging.
7-1-2. Indoor fan control (AC Fan motor)
(1) The indoor fan is operated by the stepless speed
change AC motor.
(2) For air flow level, speed of the indoor fan motor is
controlled in five steps (LOW, LOW
and HIGH). If AUTO mode is selected, the fan
motor speed is automatically controlled by the
difference between the preset temperature and
the room temperature.
LOW
MED
FAN TAP
UH H M+
M
L+
H M
H M+ M
M+ M
970
1060 1030 950
800
770 720 700
−
1060 1030
1120 900
−
770
830 800 680
1090 1000
1170 1020
900 920 760 750
−
1210 1170 1090 1000
−
750
930 900 810
− 30 −
FILE NO. SVM-05015
, MED, MED
+
LOW+MED
=
+
2
MED+HIGH
=
+
2
L+ L L- L
SUL/SL-
L L- UL
L+ L-
L
L+ L L- UL SUL
820 800 650 600
600 580 410
450
−
600
820 800 650
−
600 410
580 450
860 640
850 700 690
650 490 480
440
660
−
860 850 700 690
640
−
650 490 480
660 440
+
SUL/SL-
500
320
−
−
540
350
−
−