Switching Differential Of Actuator; Control Of Mixing Valve Actuator - Siemens RVA63.280 Basic Documentation

Benefit
Description
Important
Setting
Effect
Switching differential
148/184
Siemens Building Technologies
Landis & Staefa Division
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
Setting range
0...20
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.
°C
Y
Mixing valve actuator OPENS
Motorized valve actuator CLOSES
ON
OFF
w
Basic Dokumentation RVA63.280, RVA53.280
OEM
Unit
°C (K)
TVx
TVw+SDM/2
TVw
TVw-SDM/2
t
= TVw - SDM/2
=
°C
must be set to "2-position".
Factory setting
2
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
TVw + SDM/2
w Setpoint
36OEM Switching differential of
actuator
Switch-on point
Switch-off point
ON Mixing valve actuator
OPENS
OFF Mixing valve actuator
CLOSES
CE1P2374E
19.04.2001