Danfoss VLT FC 102 Programming Manual page 207

Parameter Descriptions
ramps up again and the pressure reaches the set value
(P ).
set
FC
External PID
controller
f
Ref
P
System
f
Out
P
Illustration 3.59 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 Configu-
set
ration Mode to [0] Open Loop.
Example: Boost system.
No-flow detection (pumps only) Yes
Low speed detection
External signal
Pressure/temperature
(transmitter connected)
Output frequency
Table 3.26 Configuration Overview
NOTICE
Sleep mode is not active when local reference is active
(press the navigation keys to set speed manually). See
parameter 3-13 Reference Site.
Does not work in hand-on mode. Carry out auto set-up
in open loop before setting input/output in closed loop.
M0010001
Programming Guide
P
Set
Internal PI controller
(parameter 1-00 Configuration Mode: Closed loop)
Sleep mode Wake up
–
Yes –
Yes –
– Yes
– No
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p
(Pressure)
P
Set
f f
(Frequency)
Ref Out
f f
Ref / Out
f
Wake
t
1
No/Low Flow Sleep mode
detected activated
Illustration 3.60 Boost System
When low power or low speed is detected, the motor is
stopped, but the reference signal (f
controller is still monitored. Because of the low pressure
created, the controller increases the reference signal to
gain pressure. When the reference signal has reached a set
value, f , the motor restarts.
wake
The speed is set manually by an external reference signal
(remote reference). Use default settings (parameter group
22-3* No-Flow Power Tuning) for tuning of the no-flow
function.
External PI controller or manual control
(parameter 1-00 Configuration Mode: Open loop)
Sleep mode
Yes (except manual
setting of speed)
Yes
Yes
–
–
22-40 Minimum Run Time
Range: Function:
10 s [0 - 600 s] Set the minimum running time for
*
the motor after a start command
(digital input or fieldbus) before
entering sleep mode.
p
System
Time
f
Ref
f
Out
Time
P = P
Ref Wake
) from the external
ref
Wake up
–
–
–
No
Yes
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