148/184
Siemens Building Technologies Basic Dokumentation RVA63.280, RVA53.280 CE1P2374E
Landis & Staefa Division 19.04.2001
3.17 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.
3.17.1 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
Motorized valve actuator CLOSES = TVw + SDM/2
°C
2373D02
w
ON
OFF
wSetpoint
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
To Next Page
Loading...
