Sharp AH-S22AW2 Service Manual page 17

2. OUTDOOR UNIT
2-1 Frequency control
(1) AC current peak control
Set value (Normal)
Model
AU-S22AW2
AU-S25AW2
(2) Control for prevention of outdoor heat exchanger overheating
If the temperature of the outdoor heat exchanger exceeds the overheating prevention lone 1 or 2 during cooling, the
operating frequency is lowered by approximately 5 to 15 Hz.
After that, the frequency is lowered by approximately 5 once every 60 seconds or approximately 15Hz once every
120 seconds.
When the temperature of the outdoor heat exchanger goes below the overheating prevention clear line, the
frequency is raised by approximately 5 Hz once every 60 seconds, and normal operation is restored.
If the frequency is lowered to 15 Hz without the temperature of the outdoor heat exchanger decreasing and this
condition lasts for 1 minute, the compressor will be stopped.
Overheating prevention line 1
Overheating prevention line 1
Overheating prevention line 1
(3) 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 discharge temperature
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 15 Hz without the discharge temperature decreasing and this condition lasts for 1
minute, the compressor will be stopped.
(4) Control for prevention of indoor heat exchanger freezing
If the temperature of the indoor heat exchanger goes below approximately 5°C during cooling(only full power
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 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.
2-2 Overcurrent protection
(1) Compressor lock detection
If the set value (3.0 A) of AC current is exceeded at 10 to 30 Hz when operation begins, operation is stopped.
In this case, the compressor 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.
(2) DC overcurrent detection, AC overcurrent detection
To protect against overcurrent due to sudden changes in load, the compressor is stopped if the set value 30 A DC
is exceeded in the DC section, or the set value 8.5 A AC is exceeded in the AC section.
In this case, the 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.
2-3 Compressor protector control
If the temperature of the compressor chamber exceeds 114°C, the compressor is stopped.
In this case, the outdoor fan does not stop, and when the compressor chamber temperature decreases to 100°C
three minutes 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.
6.2A
6.5A
56˚C
Lower 5Hz once every 60 seconds
Lower 15Hz once every 120 seconds
58˚C
55˚C
17
AH-S22AW2
AH-S25AW2