Operation with two setpoint values (min./max.
switching)
Fig. 8: Min./max. switching
1
Volume flow rate setpoint value specification (V
min
and V
max
)
2
Switch or relay for switching between V
min
and V
max
3
Actual value volume flow rate as 0–10 V DC signal,
e. g. to the central BMS
The constant values (V
min
and V
max
) set on the rotary
potentiometer can be activated alternately by volt-free
switch contacts. Switching is accomplished by switches
or relays, e. g. day/night switching.
3.5.2 Operation with variable volume flow
rate setpoint value
Fig. 9: Variable volume flow control
1
Volume flow rate limit value specification (V
min
and
V
max
)
2
Control signal 0–10 V DC at terminal w as setpoint
value input, e. g. from room temperature controller
or DCC substation or similar.
3
Actual value volume flow rate as 0–10 V DC signal,
e. g. to the central BMS
For the use of more variable volume flow rate setpoint
values, the specification of an electrical control signal
must be made by a higher-level controller (i. e., room
temperature controller, air quality controller, central
building management system, etc.). If the input signal is
changed, the controller adjusts the volume flow rate to
the new setpoint. The variable volume flow rate is
limited to a minimum and maximum volume flow rate
Chapter 3.6 ‘Characteristics’ on page 16
Override control
The constant or variable control can be disabled by
override controls, e. g. when the window is open, a
window switch stops ventilation of the room by closing
the damper blade.
Further application examples:
Circuits for quick ventilation (V
max
)
Opening the damper blade
Structure and functional description
Operating modes > Operation with variable volume flow rate setpoint value
Control component Easy for VAV terminal units
14
