Siemens AVS75.390 User Manual

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Siemens Switzerland Ltd
User manual RVS61.843 CE1U2355en_02
HVAC Products 6 The settings in detail 23. November 2007
B21
B71
Q9
B91
T
T
T
K19
B84
T
K1
Y22
E17
2355Z12
Gas low-pressure
Gas high-pressure
Liquid
Automatic defrost function
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.
2965
2963
2962
8478
2951
2959 OEM
(2963)
(2962)
8477
2952 OEM
8477
2954 OEM
8478
t
°C
1
0
2355Z16
1
0
1
0
Y22
B91
K19
K1
B84
B91 Source inlet temperature 2951 Defrost release below OT
B84 Evaporator temperature 2952 OEM Swi diff defrost
Y22 Process reversing valve 2954 OEM Evapor temp defrost end
K19 Fan source inlet 2959 Defrost settling time
K1 Compressor 1 2962 Duration defrost lock
2963 Time up to forced defrost
2965 Dripping time evapor
8477 Temp diff defrost act value
8478 Temp diff defrost setpoint
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.
Defrost end when
defrosting through
process reversal

Siemens AVS75.390 Specifications

General

Brand	Siemens
Model	AVS75.390
Category	Controller
Language	English