Assortment / System Description

Radiator application
Hot water radiator application
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The DRX2 automation station controls radiator valves via Triac or analog
outputs, regardless of available I/Os. 3-position actuators, thermal pulse width
modulation (PWM) actuators, PWM actuators with return spring can be
connected to the Triac outputs.
A maximum of 1 thermal valve can be connected to each Triac on the DXR2
automation station with AC 230 V power. PWM actuators with spring return are
not supported.
Valve actuators are operated from time to time to prevent them from seizing
after long periods of inactivity (e.g. heating valve during the summer). The valve
actuator is controlled to lose as little heating energy as possible.
The central function for the hot water supply chain performs the valve
protection function and can be changed in the parameters as needed.
Description Name Default value
Kick value KickVal 50%
Kick time TiKick 2 min
Kick cycle KickCyc 500 h
The downdraft compensation functions slows down sinking cold air current at
large window surfaces and prevents in this manner a cold wall effect on large,
cold surfaces. The function activates the radiator if the outside temperature
drops below a configured value by increasing the minimum radiator control to a
higher value. A linear reset function implements the downdraft compensation.
The control sequence is only active in the Comfort room operating mode. The
following graphic provides the factory settings for the downdraft compensation
parameters.
Y Output signal TOa Outside air temperature
Y1 100 % X1 -5 °C
Y2 0 % X2 10 °C
Figure: Downdraft compensation characteristic curve
Actuators
Valve protection
Downdraft
compensation