Sharp AH-X108E Service Manual page 29

(2) Defrosting conditions
The temperature of the outdoor heat exchanger and
the temperature of the outdoor are detected by 2
sensors, and if it stays in the preset defrost zone for
approximately 120 seconds, defrosting start is
enabled.
If defrosting is enabled when the defrost mask time
ends, defrosting is performed. If defrosting is not
enabled, the machine waits until defrosting is enabled.
Defrost mask times is 20 minutes.
The defrosting zone is decided by outdoor
temperature and
temperature.
(3) During defrosting
When defrosting begins, the compressor stops.
Approximately 1 minutes later, the compressor
reactivates in the refrigeration cycle, and the outdoor
heat exchanger is defrosted.
Each mode is as follows:
The outdoor fan is stopped
The operating frequency is 90Hz/76Hz [AY-X138E/
AY-X108E]
The indoor fan is stopped
(4) Defrost stop
When defrosting time exceeds 12 minutes
When the temperature of the outdoor heat exchanger
rises above approximately 10˚C
Defrost stop is determined by either of the above
conditions, and the compressor is stopped.
At the same time, the outdoor fan go ON. The
compressor is reactivated in the heating cycle 1
minutes after it was stopped, and normal control
resumes.
2-2 Frequency control
(1) AC current peak control
This control lowers the compressor frequency if the
AC current exceeds the set values. If the current is
below the set values, the compressor frequency will
not be raised above that frequency, as the maximum
frequency, for 1 minute.
Model
AE-X108E During heating Approximately 8.00 A
AE-X138E During heating Approximately 10.14 A
AE-X108E, AU-X108E During cooling Approximately 6.15A
AE-X138E, AU-X138E During cooling Approximately 7.50 A
(2) Control for prevention of indoor heat exchanger
overheating
If the temperature of the indoor heat exchanger
exceeds the overheating prevention line during
heating due to the operating frequency or the nature
of the operation, the frequency is lowered by
approximately 5 to 10 Hz. After that, the frequency is
lowered by approximately 5 to 10 Hz once every 60
seconds. When the temperature of the indoor heat
exchanger goes below the overheating prevention
line, the frequency is raised by approximately 5 Hz
once every 60 seconds, and normal operation is
restored.
If the frequency is lowered to minimum frequency
without the temperature of the indoor heat exchanger
decreasing and this condition lasts for 1 minute, the
compressor will be stopped.
outdoor heat exchanger
Set value
Operating frequency
During normal operation
During full power operation
(3) Control for prevention of outdoor heat exchanger
overheating
If the temperature of the outdoor heat exchanger
exceeds approximately 60°C during cooling, the
operating frequency is lowered by approximately 5 to
20 Hz. After that, the frequency is lowered by
approximately 5 to 10 Hz once every 120 seconds.
When the temperature of the outdoor heat exchanger
goes below approximately 57˚C, the frequency is
raised by approximately 5 Hz once every 60 seconds,
and normal operation is restored.
If the frequency is lowered to minimum frequency
without the temperature of the outdoor heat exchanger
decreasing and this condition lasts for 1 minute, the
compressor will be stopped.
(4) Control for prevention of discharge overheating
If the discharge temperature exceeds approximately
105°C during compressor operation, the operating
frequency is lowered by approximately 5 Hz. After
that, the frequency is lowered by approximately 5 Hz
once every 60 seconds. When the temperature of the
outdoor heat exchanger goes below approximately
104˚C, the frequency is raised by approximately 5 Hz
once every 60 seconds, and normal operation is
restored.
If the frequency is lowered to minimum frequency
without the discharge temperature decreasing and this
condition lasts for 1 minute, the compressor will be
stopped.
(5) Control for prevention of indoor heat exchanger
freezing
If the temperature of the indoor heat exchanger goes
below approximately 5°C during cooling, the operating
frequency is lowered by approximately 5 Hz. After
that, the frequency is lowered by approximately 5 Hz
once every 60 seconds. When the temperature of the
indoor heat exchanger rises above approximately 5°C,
the frequency is raised by approximately 5 Hz once
every 60 seconds, and normal operation is restored.
If the temperature of the indoor heat exchanger goes
down to approximately 0°C and this condition
continues for 4 minutes, the compressor is stopped.
When the temperature rises above approximately 2˚C,
normal operation is restored.
2-3 Overcurrent protection
(1) Compressor lock detection
If the set value (4.37 A: AE-X138E, AU-X138E / 3.83
A: AE-X108E, AU-X108E) of AC current is exceeded
at 10 to 30 Hz when operation begins, operation is
stopped. In this case, the compressor and outdoor fan
does not stop, and 170 seconds after operation is
stopped, another try will be made. Three retries are
allowed. On the fourth retry, a complete stop request
signal is sent to the indoor unit, and the outdoor unit
will remain stopped until reset is performed. At this
time, the 3-minute delay for control of the outdoor unit
will not function; therefore, do not cancel by removing
the plug and cutting the power.
29
AH/AU-X108E
AY/AE-X108E
AH/AU-X138E
AY/AE-X138E
Overheating prevention line
Above 50 to 43 to Below
50 Hz 43 Hz 37 Hz 37 Hz
54 53 52
58 57 56
51
54