Heating With Changeover Valve; Frost Protection; Pump Control; Pump Overrun - Siemens RVP201 Basic Documentation

Protection against
discharging
Heating
Protection against
discharging
Caution!
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Siemens
Building Technologies
If, in the case of boiler operation, the boiler temperature during the pump overrun time
lies below the d.h.w. temperature, pump overrun will be stopped prematurely (that is,
before the 6 minutes have elapsed). This prevents the d.h.w. from cooling down un-
necessarily.
When using a thermostat for the d.h.w. temperature, pump overrun will be stopped
when the boiler temperature lies below the adjusted d.h.w. temperature setpoint.
3.7.4 D.h.w. heating with changeover valve
If the sensor acquires a d.h.w. temperature that lies 5 K below the d.h.w. temperature
setpoint (or if the contact of the d.h.w. thermostat closes), the changeover valve will be
activated. During d.h.w. heating, the flow temperature is raised to a level that is 16 K
(fixed value) higher than the adjusted setpoint of the d.h.w. temperature. When the
d.h.w. temperature reaches the setpoint, the changeover valve will be shut down again.
D.h.w. heating is always enabled; there are no locking times.
In manual operation, d.h.w. heating is switched off; the changeover valve travels to the
position "Heating circuit" (space heating).
If, in the case of boiler operation, the boiler temperature during the pump overrun time
lies below the d.h.w. temperature, pump overrun will be stopped prematurely (that is,
before the 6 minutes have elapsed). This prevents the d.h.w. from cooling down un-
necessarily.
When using a thermostat for the d.h.w. temperature, pump overrun will be stopped
when the boiler temperature lies below the adjusted d.h.w. temperature setpoint.
3.7.5

Frost protection

The d.h.w. storage tank is protected against frost, provided a d.h.w. temperature sensor
is used.
Frost protection is automatically activated if the d.h.w. temperature falls below 5 °C.
The charging pump or the changeover valve will be activated and a d.h.w. temperature
of at least 5 °C is maintained.
When using a thermostat, the RVP211 does not provide frost protection for the d.h.w.
storage tank.
3.8

Pump control

The controller controls the heating circuit pump depending on demand. This means that
the pump will be switched on only when there is demand for heat or when frost protec-
tion for the plant has responded.
3.8.1

Pump overrun

To ensure there is no buildup of heat in the boilers (overtemperature protection), heat-
ing circuit pump and charging pump continue to run for a certain period of time after the
switch-off command has been given. The factory-set pump overrun time is 6 minutes.
Depending on the type of plant and the operational status, overrun of the heating circuit
pump and the charging pump acts as follows:
Heating controllers RVP201 and RVP211
3 Technical design
CE1P2464en
2017-07-21