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Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the heating engineer settings
18.10.2002
4.22 Additional pump Q17 for heat pump stage 2
(ZuFu5)
•
Control of an additional circulating pump with 2-stage heat pumps
With 2-stage heat pumps (2 compressors and 2 condensers), an additional circulating
pump can be used for drawing heat off the second condenser.
For the control of the second heat pump stage and the additional pump, the controller
uses the same sensor values as with the first heat pump stage. Hence, the second
pump must hydraulically be integrated such that the sensors (B21 and / or B71) are lo-
cated in the section where there is flow (refer to application example).
Setting range
Unit
Factory setting
--- / 101...110
Q17
---
The auxiliary function is activated as soon as relay Q17 is assigned a free terminal:
101...110
The relay for the second circulating pump
Q17
can be assigned to a
free relay terminal between Q101 and Q110.
---
No assignment made and the auxiliary function is not activated.
For the pump pre- and overrun (operating lines 410
EXP
and 411
EXP
), the same parame-
ters are used as with heat pump stage 1.
An additional pump for the second heat pump stage Q17 can be integrated in the plant
diagram as follows:
Example:
K2
Q17
ZuFu 5
B21
K1
Wp 4
B11
B71
Q8
Q9
Benefit
Description
Important
Setting
Assignment
Note
Application example