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Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the heating engineer settings
18.10.2002
4.115.1 Generation of heat demand (Setting 1)
The current heat demand signal passed to the boiler is generated based on the heat
demand from the d.h.w. or buffer storage tank.
Which of the 2 storage tanks is charged first and which heat demand therefore applies
is defined by the storage tank priority.
The heat demand of d.h.w. is shifting. The controller adds the required temperature
boost (operating line 776) for efficient charging to the measured actual value of the
d.h.w. temperature (sensor at the top) and uses the mixing valve to maintain the boiler
temperature at the required level.
The heat demand from the buffer storage tank is made depending on the setpoint. The
setpoint used is the value of the slave pointer. The controller uses the mixing valve to
maintain the boiler temperature at the required level.
A description of the slave pointer is given in chapter 6, “General control process”.
4.115.2 Storage tank priority
Storage tank priority in the case of charging by the wood-fired boiler is dependent on
the current d.h.w. operating mode (d.h.w. button pressed or not pressed) and the defi-
nition of input H1.
If, at input H1, “Charging priority d.h.w. for heat from the wood-fired boiler” was se-
lected (operating line 870), storage tank priority can also be influenced via input H1.
The priority will be defined depending on the combination of settings:
D.h.w. button not pressed,
input H1 open
First, the buffer storage tank will be fully charged,
then the d.h.w. storage tank.
D.h.w. button pressed, input
H1 open
(factory setting)
First, the buffer storage tank will be recharged, that is,
the upper part (sensor at the top) will be charged until
the required setpoint is reached. Then, the d.h.w.
tank will be fully charged. Then, the rest of the buffer
storage tank will be charged (down to the sensor at
the bottom).
Input H1 closed
(d.h.w. button not relevant)
First, the buffer tank will be fully charged, then the
d.h.w. storage tank.
Heat demand d.h.w.
storage tank
Heat demand buffer
storage tank