Sharp AE-XM24HR, Service Manual

Page: 10 / 50

AEXM24HR
2 – 2
[2] FUNCTION
1. OUTDOOR UNIT
1.1. FREQUENCY CONTROL
(1) AC current peak control
(2) Prevention control of outdoor heat exchanger overheating
If the temperature of the outdoor heat exchanger exceeds the
over heating prevention line 1or 2 during cooling, the operating
frequency is lowered by approximately 5 to 15Hz.
After that, the frequency is lowered
approximately 5Hz 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 5Hz
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.
(3) Prevention control of compressor overheating If the temperature
of the compressor exceeds approximately 108
°
C the operating
frequency is lowered approximately 5Hz.
After that, the frequency is lowered approximately 5Hz once every
60 seconds.
When the compressor temperature drops below approximately
108
°
c, the frequency is raised
approximately 5Hz once every 60 seconds, and normal operation
is restored.
If the frequency is lowered to minimum frequency without the
temperature of the compressor decreasing,and this condition lasts
for 1 minute, the compressor will be stopped.
(4) Prevention control of indoor heat exchanger overheating
Two minutes after room several decrease If the temperature of any
of indoor heat exchangers exceeds the overheating prevention line
1 or 2 during heating, the operating frequency is lowered to
minimum frequency.
When the temperature of all of indoor heat exchangers go below
the overheating prevention line 1, the frequency is raised by
approximately 5Hz once every 60 seconds, and normal operation
is restored.
If the condition that the frequency is minimum lasts for 2 minutes,
the compressor will be stopped.
<when nomal>
if the temperature of any of indoor heat exchangers exceeds the
overheating prevention line 1 or 2 during heating, the operating
frequency is lowered by approximately 5 to 15Hz.
After that , the frequency is lowered approximately 5Hz once every
60 seconds or approximately 15Hz once every 90 seconds.
When the temperature of all of indoor heat exchangers go below the
overheating prevention line 1, the frequency is raised by
approximately 5Hz once every 60 seconds, and normal operation is
restored.
If the condition that the frequency is minimum lasts for 2 minutes, the
compressor will be stopped.
1.2. OVER CURRENT PROTECTION
DC over current detection, AC over current detection
To protect against over current due to sudden change in load,the
compressor is stopped if 55A DC is exceeded in the DC section.
If the set value of AC current is exceeded in the AC section, the
compressor is stopped. 90 seconds after the compressor has been
stopped, another starting 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 the indoor operation is stopped.
DC over current is detected by the power module.
AC over current is detected by CT1 on the outdoor PWB.
1.3. COMPRESSOR PROTECTION CONTROL
If the temperature of the compressor exceeds 113
°
C the compressor
is stopped.
In this case, the outdoor fan is not stopped until the temperature of
compressor drops below 99
°
C.In 90 seconds after the
compressor is stopped, if the temperature is below 90
°
C another
starting 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 the indoor
operation is stopped.
1.4. POWER TRANSISTOR MODULE PROTECTION
If the temperature of the chips in the power transistor module
exceeds 100
°
C,the compressor is stopped.
In this case, the outdoor fan is not stopped until the temperature of
power module drops below 85
°
C. In 90 seconds after the
Cooling mode Heating mode
AE-XM24HR 16.5A 16.5A
Overheating Prevention
line 1 55
°
C Lower 5Hz once every 60
seconds
Overheating Prevention line
2 57
°
C Lower 15Hz once every 120
seconds
Overheating Prevention
clearline 54
°
C
Cooling mode Heating mode
AE-XM24HR 19.3A 19.3A
When ON
(When OFF)
Overheating
prevention
line 1
900
44
(57 )
54
48
51
57
47
(60 ͠ )
2100 5200 7200
Overheating
prevention line 2
When ON
(When OFF)
Overheating
prevention
line 1
900
44
(57
54
48
51
57
47
(60
2100 5200 7200
Overheating
prevention line 2
͠
͠
͠
͠
͠
(62 ͠ ) (6
(59 ͠ ) ͠
(57 ͠ )
͠
(54
͠
)