Siemens RVA63.242 - Switching Differential of Actuator; Control of Mixing Valve Actuator

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Siemens Building Technologies Basic Documentation RVA63.242, RVA53.242 CE1P2373E
Landis & Staefa Division Description of OEM settings 26.03.2001
5.27 Switching differential of actuator
Optimum control of 2-position mixing valve.
For a 2-position actuator, a switching differential can be adjusted, allowing the 2-
position control to be optimally matched to the type of actuator used.
The actuator’s mode of control on setting line 35
OEM
must be set to "2-position“.
Setting range Unit Factory setting
0...20 °C (K) 2
This setting changes the switching differential of mixing valve actuator Y1.
Entry:
Increase: Switching differential will become larger
Fewer and longer heating up times, larger temperature variations.
Greater temperature variations in the heating circuit.
Decrease: Switching differential will become smaller
More frequent and shorter heating up times, smaller temperature
variations.
Smaller temperature variations in the heating circuit.
5.27.1 Control of mixing valve actuator
2-position control provides control of the motorized mixing valve by delivering pulses.
Generally, this means: The greater the amount of heat needed, the longer the heating
up time.
Y
°C
TVx
TVw+SDM/2
2373D01
TVw-SDM/2
t
TVw
Legend
TVx Actual value of the flow
temperature
TVw Flow temperature setpoint
SDM Switching differential of actuator
Y Mixing valve actuator OPENS
Y Mixing valve actuator CLOSES
Mixing valve actuator OPENS = TVw - SDM/2
Mixing valve actuator CLOSES = TVw + SDM/2
°C
2373D02
w
ON
OFF
w Setpoint
36OEM Switching differential of actuator
Switch-on point
Switch-off point
ON Mixing valve actuator OPENS
OFF Mixing valve actuator CLOSES
Benefit
Description
Important
Setting
Effect
Switching differential