Siemens RVS41.813 - Page 132

B91 Source inlet temp 2951 Defrost release below OT
B84 Evaporator temp 2952 OEM
2953 OEM
Swi diff defrost
Temp diff defrost max
Y22 Process reversing valve 2954 OEM Evapor temp defrost end
K19 Fan source inlet 2959 OEM Defrost settling time
K1 Compressor 1 2962 Duration defrost lock
2963 Time up to forced defrost
2965
2966 OEM
Dripping time evapor
Cooling down time
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.
Defrosting with the fan is considered completed when one of the 2 following conditions
is satisfied:
• The temperature difference (8477) between incoming outside air (B91) and
evaporator (B84) is smaller than that set by your supplier
• When defrosting with the fan, the defrost time is reached
The defrost process at low outside temperatures takes more time than at higher outside
temperatures.
Defrost end when
defrosting through
process reversal
Defrost end when
defrosting with the fan
Y22
1
B91
B84
[8477]
T
A
Sta
rt defrosting
df ti
[8478]
[2953]
[2953]
[
2963
]
[
2962
]
[
2959
]
[
2965
]
[
2963
]
[
2962
]
[
2951
]
[
2954
]
[8478]
[2952]
Start defrostin
g
Actual diff ice free
Diff = 0
0
1
0
0
1
K19
K1
[
2966
]
132/258
Siemens Switzerland Ltd User manual RVS61.843, RVS41.813 CE1U2355en_02
HVAC Products 6 The settings in detail 28. September 2009