Application example:
B21
K1/E11
B71
B83
B81 E10
P
E9
P
B92
Q8/E14
B91
E15
P
Q3
KW
TWW
Y21
Y1/Y2
B4
B3
B41
Q2
B9
B1
RG1
Y21
Active and passive
cooling
In the case of plants that support both passive and active cooling, the controller
switches automatically from passive to active cooling, and vice versa. Simultaneous
active and passive cooling is not possible.
As long as the temperature acquired by the source inlet sensor (B91) lies below the
cooling request, cooling is passive.
If the source temperature exceeds the cooling request, the controller switches to active
cooling.
The HP partial diagram used must support this function (HP 22, 23, 42, 43).
If a source inlet sensor (B91) is used, the temperature acquired by the source outlet
sensor (B92) is used as the changeover criterion.
Parameter setting
examples with active
and passive cooling
The 3 following parameter setting examples show heat pump plant diagrams that make
possible automatic changeover between active and passive cooling mode.
The actively produced cooling energy is delivered to the consumers via the heating /
cooling pipes.
For the passively produced cooling energy, parameter "During compressor operation"
can be used to select indirectly the pipes via which cooling energy shall be delivered to
the consumers:
Passive cooling while the compressor is off
The passive cooling enery is diverted to the heating / cooling pipe.
If there is a DHW request, it is satisfied by the heat pump via the common heating /
cooling pipe. If there is a cooling request at the same time, it cannot be satisfied.
Passive cooling while the compressor is on
Passive cooling is effected via the cooling pipe. If there is a DHW request, it is satisfied
by the heat pump via the heating / cooling pipe. If there is a cooling request at the same
time, it can simultaneously be satisfied via the cooling pipe.
If passive cooling is effected via the heating / cooling pipe, parameter "In passive
cooling mode" (3007) can be used to define whether the condenser pump shall be
switched on or off.
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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