Sharp AY-A079E Service Manual page 12

AY/AE-A079E
AY/AE-A099E
7. Current control
This system, in order to prevent overcurrent during
heating operation, controls the outdoor fan motor and
changes the indoor fan motor speed by detecting total
current.
When the current exceeds P2, the outdoor fan motor is
automatically turned off, and when the current falls
below P4, the outdoor fan motor is turned on.
When the current exceeds P3 and the indoor fan speed
shifts down because of cold air (5. Preheat air flow), the
changes in the indoor fan speed shifts up as follows,
from "off" to "UL", or from "UL" to "L". And when the
current falls bellow P5, the indoor fan speed shift up is
canceled.
Current transition
Outdoor Indoor
Fan motor Fan motor
OFF Shift UP
Figure Y-10
8. Freeze preventive
When the indoor pipe temperature falls below -1˚C
during cool operation or dry operation, the compressor
is turned off.
9. Defrost
The defrost timer (integrating the operation time of
compressor) counts time with microcomputer during
heat operation.
Frost of outdoor pipe is estimated by indoor pipe
temperature (TH2), room temperature (TH1), indoor
fan speed and operation state of compressor.
In the defrost operation, first the compressor is turned
off, the fan speed is set to "UL" and the outdoor fan
motor is turned off.
30 seconds later the indoor fan motor is turned off, 50
seconds later the reverse valve is turned off, and 60
seconds later the compressor is turned on.
In the end of defrosting, the compressor is turned off,
the outdoor fan motor is turned on, 50 seconds later the
reverse valve is turned on, 60 seconds later the
compressor is turned on, starting heat operation.
At this time, the indoor fan motor is turned off or the fan
speed is set to "UL" if preheat air flow function is
effective.
AY- AY-
A079E A099E
P1 5.3A 6.9A
P2 4.5A 6.1A
P3 4.0A 5.4A
P4 3.4A 4.6A
P5 2.6A 4.2A
Time
Compressor
OFF
Switch ON
Heating
Min.
40min.
Figure Y-11
Defrost start
50sec. 10sec.
ON
Compressor
OFF
ON
Reverse
Valve
OFF
ON
Outdoor
Fan Motor
OFF
ON
UL
Indoor
Fan Motor
OFF
Figure Y-12
10. Delayed operation of the reverse valve
When the heat operation is shut down or the operating
mode is switched from heat to cool or dry, or vice versa,
the reverse valve is switched after 3 minutes.
11. Test run
If the "TEST RUN" button in the unit is pushed during
suspension of operation, cool test operation starts. At
this time, the fan speed is set to "AUTO".
If this button is pushed during operation, the test
operation starts in current operation mode. The
operation LED (red) flickers during test run.
In cool and heat mode continuous compressor on
operation is performed. In dry mode the operation is in
dehumidifying zone. In fan only mode the indoor fan
motor runs continusly.
12. Timer
12-1 24-HOUR PROGRAMMABLE ON/OFF TIMER
ON-TIMER or OFF-TIMER can be independently
programmed. When the unit operates during one
hour after the OFF-time is set, thermostat setting
is automatically shifted (+1˚C in cool operation
and dry operation, -3˚C in heat operation, 16˚C -
32˚C).
When the ON-timer is set in heat operation and
cool operation, operation starts before 0 to 30
minutes(depends on the room temperature) so
that preset temperature is obtaind at set time.
12-2 ONE-HOUR TIMER
When ONE-HOUR timer is set, the unit turns off
automatically after one hour. The one hour timer
operation has priority over other time operation,
such as the TIMER ON and TIMER OFF. If the
ONE-HOUR TIMER button is pressed again
during operation, the unit will operate additionally
for another one hour.
12
Defrost Defrost
Heating
Heating
Max. Min. Max.
11min. 30min. 11min.
50sec. 10sec.
MAX. 9min.
60sec.
30sec.
Preheat Air
Flow Control