Mode Of Operation Without Room Sensor; Protective Functions; Pump Kick; Valve Kick - Siemens RVD230 Basic Documentation

Siemens Building Technologies
HVAC Products

12.10.3 Mode of operation without room sensor

The controller continually determines the room temperature as a function of the flow
temperature.
If the room temperature falls below the adjusted setpoint for frost protection, the con-
troller will activate the heating circuit pump and control the flow temperature such that
the relevant room temperature will lie above that setpoint by the amount of the switch-
ing differential of 1 K. This is ensured provided the heating curve slope is correctly set.
Without the room temperature sensor, frost protection for the building has no priority
over the ECO function.

12.11 Protective functions

This section covers functions that act on several function blocks.

12.11.1 Pump kick

The pump kick prevents the pumps from seizing.
The pump kick can be deactivated on operating line 146. If activated, it acts in every
operating mode. It is also performed when the heating circuit is in standby.
The pump kick function is activated for 30 seconds every Friday morning at 10:00.
If several pumps must be kicked, they are activated one after the other in the order Q1,
Q2, Q3, Q4 and K6. The kicks are separated by pauses of 30 seconds. If, with the
selected plant type, a certain pump is not present, the relevant kick will be omitted.
The pump kick can also be interrupted by heat source- or consumer-dependent signals.
In the case of plant types with a common flow and a pump heating circuit, pump Q1 will
not be kicked when d.h.w. is heated or when the respective pump overrun is still in
progress. The pump kick will not be carried out later.

12.11.2 Valve kick

The valve kick function is activated every Friday after the pump kick.
The control outputs for the mixing valve actuators in the secondary circuits (separate
heating circuit, d.h.w. circuit) are activated for 30 seconds one after the other, that is,
the mixing valves will open. The control system will then deliver the closing command.
The kicks are separated by pauses of 30 seconds.
When there is a demand for heat and the mixing valve is "busy", there will be no valve
kick.
2-port valves in the primary circuits are not kicked.

12.11.3 Shutdown of pump

The pump is shut down to provide protection against overtemperatures. The function is
activated when, for the heating circuit, a maximum limit value for the flow temperature has
been entered (operating line 95).
If the flow temperature exceeds the maximum limit value for the flow temperature by
7.5 °C, the pump in the heating circuit flow will be shut down. It starts running again
after the flow temperature has dropped below the limit value.
Shutdown of the pump is not a safety function!
Basic Documentation RVD230
12 Function block Space heating
53/130
CE1P2383en
27.05.2004