Automatic Defrost Function - Siemens Albatros2 User Manual

Automatic defrost function

Defrost end when
defrosting through
process reversal
Siemens Switzerland Ltd
HVAC Products
K1
B84
Y22
T
B91
T
E17
K19
When the compressor is in operation, "Duration defrost lock" (2962) and "Time up to
forced defrost" (2963) elapse. If the source temperature (B91) drops below the defrost
release temperature (2951), the defrost release function will be released. The heat
pump can change to defrost operation mode after "Duration defrost lock" at the earliest,
and on completion of "Time up to forced defrost" (2963) at the latest.
When, due to icing up during this period of time, the temperature difference (8477)
between incoming outside air (B91) and evaporator (B84) exceeds the setpoint (8478),
the defrost function is triggered.
°C
8478
2954 OEM
B91
2951
B84
(2962)
1
Y22
0
1
K19
0
1
K1
0
B91 Source inlet temperature
B84 Evaporator temperature
Y22 Process reversing valve
K19 Fan source inlet
K1 Compressor 1
When defrosting is successful, the evaporator temperature (B84) rises. If the
evaporator temperature exceeds "Evapor temp defrost end" (2954 OEM), the defrost
process can be successfully completed and the compressor is switched off during the
dripping time (2965). Then, heating mode is resumed.
User manual RVS61.843
6 The settings in detail
B21
Q9
T
B71
T
8477
(2963)
2959 OEM
2965
2951
2952 OEM
2954 OEM
2959
2962
2963
2965
8477
8478
Gas low-pressure
Gas high-pressure
Liquid
8478
2952 OEM
8477
2963
2962
t
Defrost release below OT
Swi diff defrost
Evapor temp defrost end
Defrost settling time
Duration defrost lock
Time up to forced defrost
Dripping time evapor
Temp diff defrost act value
Temp diff defrost setpoint
117/221
CE1U2355en_02
23. November 2007