On completion of the number of hours set, the heat source sequence in the cascade
changes. It is always the heat source with the next higher device address that takes on
the role of lead heat source.
1
st
changeover 2
nd
changeover 3
rd
changeover 4
th
changeover
K 1
K 2
K 3
K 4
K 2
K 3
K 4
K 1
K 3
K 4
K 1
K 2
K 4
K 1
K 2
K 3
t [h]
100
300
400
200
P [kW]
237
9Z
07
Slave source
Lead source
t
= total number of operating hours of all lead heat sources
=
total output of cascade
[kW]
Setting of the source sequence exclusion is only used in
connection with the activated source sequence (3540).
Auto source seq exclusion
With source sequence exclusion, the first and / or the last heat source can be
exempted from automatic changeover.
None
The order of switching on the heat sources changes when the number of hours set is
reached (3540).
First
The first heat source in the addressing scheme always remains the lead heat source.
With the other heat sources, the order of switching on changes when the set number of
hours is reached (3540).
Last
The last heat source in the addressing scheme always remains the last. The other heat
sources change when the set number of hours is reached (3540).
First and last
The first heat source in the addressing scheme always remains the lead heat source.
The last heat source in the addressing scheme always remains the last. The heat
sources in between change when the set number of hours is reached (3540).
@ @
Electric immersion heaters in the cascade
Many heat pumps are equipped with an electric immersion heater (K25) in the flow
(directly after the condenser). The electric immersion heaters can be of the 2- or 3-
stage type (K25 and K26).
If all compressor stages of the cascade are released, the electric immersion heater of
the heat pump with first priority is released. Electric immersion heaters are released
according to the same criteria as heat pumps (release and reset integral). The heat
pump reports to the source master when all stages of the electric immersion heater are
released, or when no electric immersion heater is available.
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Siemens Switzerland Ltd
User manual RVS61.843, RVS41.813
CE1U2355en_02
HVAC Products
6 The settings in detail
28. September 2009