Siemens RVL481 - Excess Mixing Valve or Heat Exchanger Temperature; Pulse Lock

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Siemens Heating and D.h.w. Controller RVL481 CE1P2541en
Building Technologies 11 Function block "3-position actuator heating circuit" 20.05.2008
11.4 Excess mixing valve or heat exchanger
temperature
In interconnected plants, an excess mixing valve or heat exchanger temperature can be
entered on the RVL481. This is a boost of the respective heating zone's flow tempera-
ture setpoint. The higher setpoint is delivered to the heat source as the heat demand
signal.
The excess mixing valve or heat exchanger temperature is set on the controller that
drives the mixing valve (controller N2 in the example below) (operating line 84).
N2
w
N2
w
N1
= w
N2
+ w
2540S07
w
N2 +
w
w
BUS (LPB)
N1 Boiler temperature controller (heat generation)
N2 Flow temperature controller (heating zone)
w
N1
Setpoint of boiler temperature controller
w
N2
Setpoint of flow temperature controller
∆w Excess mixing valve temperature (set on controller N2)
11.5 Pulse lock
If, during a period of time that equals five times the running time, the actuator has re-
ceived only closing pulses, additional closing pulses delivered by the controller will be
locked. This minimizes the strain on the actuator.
For safety reasons, the controller delivers a one-minute closing pulse at 10-minute
intervals.
An opening pulse negates the pulse lock.
Example interconnected
plant