SHARP(CHINA)INVESTMENT CO.,LTD 
CHAPTER 3. FUNCTION AND OPERATION OF PROTECTIVE PROCEDURES 
[1] PRETECTION DEVICE FUNCTIONS AND OPERATIONS 
 
Operation
FUNTION
Description
1
Compressor 
discharge over heat  
shut-down 
Discharge temperatureTP2 
(95 ), forć bid the frequency 
raise. 
Discharge temperatureTP3 
(100 ),drop the operating ć
frequency. If discharge tem- 
perature over 105ć, shut- 
down the compressor,outdoor 
fan motor stops after   
15 seconds. 
When 
compressor is 
in  operation 
Discharge temperature 
is below than TP2-2 .ć  
Discharge temperature
˘ TP2(95 )ć . 
Discharge temperature
˘ TP1(90 )ć  and after 
compressor stops for 3 
minutes. 
P4    none  yes 
2
Compressor delaye 
operation 
The  compressor delayes 3 
minutes to restart   
When the com- 
pressor stopes 
The compressor stops 
for 3 minutes 
none none none 
3
Lower  voltage  
preventiion 
The  unit  stops if AC  
158V 
When the unit in 
operation 
When   AC162V  P1    none  yes 
4
Higher voltage  
preventiong 
The unit  stops  if 
AC265V 
When the mach-
ine in operation 
When  AC260V  P1    none  yes 
5
Over current  When the outdoor current 
I
max
,the compressor stops 
and outdoor motor stops after 
15 seconds   
When the 
machine in 
operation 
When the outdoor 
current˘I normal 
P2    none  yes 
6
Compressor drive   If the system can’t check the 
feed-back signal of compress-
or or load is  exceptonal or 
driver fail then  shut down 
the  outdoor unit 
When the com- 
pressor drives or 
operates. 
Operation offf of on  P9      none  yes 
7
Indoor unit evaporator 
frezze prevention 
Compressor stops if indoor 
pipe temperature IPT-1 ć 
and remains 5minutes 
When in cooling 
or dehumidifying 
operation 
Automatic reset when 
indoor pipe temperature 
IPT 6 ć  and remains 
10 minutes 
P5   none  yes 
8
Outdoor unit overheat 
prevention 
Compressor shtops if the 
outdoor unit  heatexchanger 
temperature OPTTOP4 
When the unit in 
operation 
When the outdoor pipe 
temperature OPTTOP1 
P6 outdoor 
light flash 
5cycle 
none yes 
 
 
9
Indoor unit overheat 
prevention  
Compressor stops if indoor 
exchaege temperature 
IPTTIP4 
When the unit is 
in operation 
When the indoor pipe 
temperature IPTTIP1 
P7 yes none 
10
IPM pretector  The outdoor unit shutt down if 
the IPM checks the 
temperature of IPM itself  or 
the current is too high 
When the unit is 
in operation 
When the IPM chck the 
temperature of IPM itself 
or the current fall to 
normal 
P0   none  yes 
11
Outdoor unit heat 
exchanger thermistor 
short-circuit  
Indoor and outdoor unit stops 
if there is short-circuit or 
break in outdoor unit heat 
exchanger thermistor 
At compressor 
startup 
Operation OFF or ON  E3  yes  yes 
12
Outdoor unit outside 
air temperature ther- 
mistor open-circuit 
error 
 
Indoor and outdoor unit stops 
if there is short-circuit or 
break in outdoor unit heat 
exchanger thermistor 
At compressor 
startup 
Operation OFF or ON  E8  yes  yes 
 
 
 
3-1 
Detection
period
Reset condition
Indoor unit
error display
Self-daignosis
result display
Indoor
unit 
Outdoor 
unit