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Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the heating engineer settings
18.10.2002
4.29 Third buffer storage tank temperature sensor
B42 (ZuFu11)
•
Precise knowledge of the buffer storage tank’s charging state
•
Possibility of partial buffer storage tank charging
When using oil-fired / gas-fired boilers for charging, the third buffer storage tank sensor
B42 enables the storage tank to be charged up to this sensor and reserve the rest of
the tank to be charged by the solar collectors.
In that case, sensor B41 is used only for controlling charging by means of the solar
collectors.
Setting “Recharge control” on operating line 470 must be 1 (B4 and B41 / B42) to allow
start (B4) / stop (B42) control. Otherwise, the use of an additional buffer storage tank
sensor makes no sense.
In that case, control of solar charging is accomplished via sensor B41 and the switching
differentials that can be set on operating lines 329…332 (ON / OFF temperature differ-
entials).
Setting range
Unit
Factory setting
--- / 101...109
B42
---
The auxiliary function is activated as soon as the third buffer storage tank sensor B42 is
assigned to a free terminal:
101...109
Buffer storage tank sensor
B42
can be assigned to a free sensor ter-
minal between B101 and B109.
---
No assignment made and the third buffer storage tank sensor is not
activated.
Auxiliary function 11 (third buffer storage tank sensor) and auxiliary function 2 (partial
storage tank charging) can be active
at the same time
. If the same storage tank sen-
sor shall be used for both functions, the relevant sensor must be connected in parallel
to both terminals.
The third buffer storage tank sensor can be integrated in the diagram as follows:
Example:
B4
B41
Sp 2
B42
ZuFu 11
23
93
Z0
11
Benefit
Description
Note
Setting
Assignment
Note
Application example
