Haier MRV 5-RC VP1-112B Service Manual page 171

3.17 Refrigerant recovery control during maintenance
(1) When the outdoor unit is discarded and transferred, the refrigerant needs to be recovered from the outdoor unit.
At this time, the outdoorl unit performs the refrigerant recovery operation. (The refrigerant in the system is recycled
to the outdoor unit)
(2) This control operation by hand
(3) Operation step:
① Turn on the unit for cooling operation
② Close the liquid pipe stop valve of each outdoor unit
③ After the low pressure of each outdoor unit is lower than 0.1 MPa for 10 seconds, closed the gas pipe stop valve
of each outdoor unit at the same time.
④ The units are powered off and the refrigerant recovery is ended
3.18 Broken sensor detection and required temperature range
(1) The sensor's style range and breakage detection value
No.
1
2 Toil1, Toil2, Td1, Td2
3 Ts, Ts1, Ts2, Tsco
4
5 Tdef1, Tdef2, Toci1, Toci2, Tliqsc
6
7 High pressure
8 Low pressure
(2) Disconnection detection method
① Detecting the AD value of temp. sensor less than 11 (open circuit) or more than 1012 (short-circuit) continuously
for 60 seconds, the failure be confirmed and unit alarm.
② Toil1, Toil2, Td1, Td2, Toilp, and Tsuc sensor, do not judge the disconnection fault when the outdoor temperature
is lower than 0°C.
③ The high-pressure and low-pressure sensors detect AD values less than 11 (open circuit) or more than 1012
(short-circuit) continuously for 30 seconds, alarm. During defrosting and after defrosting 3 minutes, do not alarm.
Sensor
Tfin
Tao
Toilp, Tsuc
Unit Application range
-10~140
℃
-20~140
℃
-40~75
℃
-40~75
℃
-40~75
℃
-20~140
℃
MPa 0~4.15MPa
MPa 0~1.7MPa
168
Disconnection range
-11℃ below
-30℃ below
-50℃ below
-50℃ below
-50℃ below
-30℃ below
0V below or 3.49V
above