Siemens RVS41.813 User Manual page 120

Red switch-off temp max
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Siemens Switzerland Ltd
HVAC Products
T
2844
2845
SD
Komp
0°C
1
S1
0
1
TWW
0
2844 Switch-off temp max
2845 Red switch-off temp max
Anf Temperature request from the consumers
SD Compressor switching differential
Komp
ON Switch-on point
OFF Switch-off point
OFF DHW Switch-off point DHW
S1 Speed 1
TWW DHW charging
In the case of DHW charging, forced buffer storage tank charging and when operating
the second compressor stage, "Switch-off temp max" (2844) is reduced by this value.
If the flow or the return temperature (B21 / B71) exceeds this level, DHW charging or
forced buffer storage tank charging is prematurely aborted and a change to space
heating takes place, provided space heating calls for heat.
In this case, the heat pump continues to operate with no interruption. The heating
circuit setpoint is not considered for a stabilization period of 2.5 minutes and after the
DHW charge is interrupted. In other words the compressor remains switched on
independent of the return temperature so that the heat pump can stabilize at the new
temperature.
The electric immersion heat complete the DHW charge if available in the DHW storage
tank and the heat pump is made available immediately for room heating. The electric
immersion heating completes the charge if one is available only in the flow and the
parameter 'Use electric flow' is not set to 'Substitute'. The compressor remains locked
during this period.
DHW charge is interrupted if no electric immersion heater is available.
The parameter 'Number: DHW charging attempts' set the number of attempts taken by
the heat pump until storage tank charging is cancelled or completed using an electric
immersion heater.
If there is no demand for heat from space heating, the heat pump is switched off.
It can only resume operation when the minimum off time (parameter 2843) has
elapsed, provided the flow or return temperature (B21 / B71) has dropped below the
reduced maximum switch-off temperature by the amount of the adjustable switching
differential (parameter 2840).
If a second compressor is in operation, it is always switched off when the reduced
switch-off temperature is reached, and no status message is displayed. During DHW
charging, or in the case of forced buffer storage tank charging, compressors 1 and 2
are switched off at the same time.
The max. switch off temperature is increased by the amount parameterized as a
negative reduction if a negative value is entered as the reduction. The DHW charge is
cancelled when the flow reaches the increased switch off temperature. The compressor
User manual RVS61.843, RVS41.813
6 The settings in detail
Anf
OFF
OFF TWW
ON
t
CE1U2355en_02
28. September 2009