Danfoss VLT FC 102 Programming Manual page 503

Programming Guide | VLT® HVAC Drive FC 102
If no-flow is detected, the drive increases the setpoint for pressure to ensure a slight overpressure in the system (boost set in
parameter 22-45 Setpoint Boost). The feedback from the pressure transducer is monitored, and then this pressure has dropped with a
set percentage below the normal setpoint for pressure (P
FC
f
Ref
f
Out
Figure 87: Boost System
2.
In systems where the pressure or temperature is controlled by an external PI controller, the wake-up conditions cannot be based on
feedback from the pressure/temperature transducer as the setpoint is not known. In the example with a boost system, the desired
pressure, P , is not known. Set parameter 1-00 Configuration Mode to [0] Open Loop.
set
p
(Pressure)
P
Set
f f
(Frequency)
Ref Out
f f
Ref /
f
Wake
No/Low Flow
detected
Figure 88: Example with Boost System
© 2024.10
External PID
controller
P
Set
P
System
P
p
System
Out
f
Ref
t
f
1
Out
Sleep mode
activated
P
). The motor ramps up again and the pressure reached the set value (P
set
Time
Time
= P
Ref Wake
Parameter Descriptions
AU430028034214en-001901 / 130R0310 |
).
set
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