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Siemens Building Technologies
Basic Documentation RVD230
CE1P2383en
HVAC Products
16 Function block D.h.w. heating
27.05.2004
value is integrated and an uncritical locking signal in the range of 0…100 % is gener-
ated, corresponding to the integral value.
•
If the consumer master is in segment 0, the locking signal will be sent to all controllers
in the interconnected system
•
If the consumer master is not in segment 0, the locking signal will only be sent to all
controllers in the same segment and to the controller that demands d.h.w.
With plant types 5–x, 6–x and 7–x, the RVD230 has this consumer master functionality.
If there is no consumer master, shifting priority only works the same way as with a
controller without LPB link.
16.6.4 No priority
No priority means parallel operation. D.h.w. charging has no impact on the heating
circuits. The heat consumers will not be restricted.
In a pump heating circuit, it can occur that too hot water is fed to the heating circuit;
caution must be exercised especially in the case of underfloor heating systems (refer to
subsection 17.1.7 "Protection against overtemperatures". By contrast, a mixing heating
circuit is able to reduce the flow temperature by adding colder return water to the flow.
The generation of the valid flow temperature setpoint can be selected by making a
setting on operating line 106:
3 = the flow temperature setpoint will be determined by the demand for d.h.w.
4 = the flow temperature setpoint will be determined by a maximum selection of the
valid demands for heat
16.7 Pump
overrun
16.7.1 General
To prevent heat from accumulating, it is possible to select overrun of the intermediate
circuit pump and of the storage tank charging pump, depending on the type of plant.
The type of priority has no impact on the overrun function. By contrast, pump overrun
can be interrupted by the d.h.w. discharging protection, or extended by locking signals.
The simultaneous overrun of heating circuit pumps and d.h.w. pumps is permitted.
16.7.2 Intermediate circuit pump
The overrun time can be set on operating line 107. When setting 0 minutes, the func-
tion will be deactivated.
The d.h.w. intermediate circuit pump overruns for an adjustable period of time if, previ-
ously, d.h.w. charging has taken place. With plant types 2–11 and 2–12, the diverting
valve is regarded as a d.h.w. pump.
16.7.3 Storage tank charging pump
For the storage tank charging pump, an additional overrun time can be set on operating
line……... This overrun time is added to the overrun time of the intermediate circuit
pump. When setting 0 seconds, the pump overrun times are the same.
In applications with an intermediate or mixing circuit, the storage tank charging pump
stops with no overrun if the d.h.w. flow temperature B1 or B3 falls below the actual
storage tank temperature.
