Danfoss VLT AutomationDrive FC 361 Programming Manual page 157

Parameter Descriptions
2) Systems where the integrated PI controller is used for
controlling pressure or temperature, for example boost
systems with a pressure feedback signal applied to the
frequency converter from a pressure transducer.
Set parameter 1-00 Configuration Mode to [3]
1.
Process.
2. Configure the PI controller for reference and
feedback signals.
Illustration 4.51 Sleep Mode Function
Pressure/temperature
(transmitter connected)
Output frequency
Boost function
Sleep mode enable
Table 4.21 Configuration Overview
The goal of the boost function is to keep the frequency converter in sleep mode as long as possible to avoid cycling the
motor on and off frequently, and also keep the controlled system variable within the acceptable range. Boost is only to be
used when parameter 1-00 Configuration Mode is set to [3] Process, and the integrated PI controller is used.
NOTICE
Sleep mode is not active when local reference is active (set speed manually with the navigation keys on the LCP). 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.
MG06J202
Programming Guide
P
System
External PI controller or manual control
(parameter 1-00 Configuration Mode: Open loop)
Sleep mode activated
–
Yes
–
External DI signal (parameter group 5-1* Digital Inputs)
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p(Pressure)
P
Boost
P
P Ref
Set
P
Wake-up
f (Frequency)
f
out
Ref
f
O ut
Digital input
Boost
activated
enabled
Illustration 4.52 Sequence Diagram
If the difference between pressure reference and feedback
is smaller than the threshold, the boost function activates,
which means the frequency converter increases the
setpoint for pressure to ensure a slight overpressure in the
system (the boost is set in parameter 22-45 Setpoint Boost).
The feedback from the pressure transducer is monitored.
When this pressure has dropped with a set percentage
below the normal setpoint for pressure (P
ramps up again. The pressure is then controlled for
reaching the set value (P
set
(parameter 1-00 Configuration Mode: Closed loop)
Wake up Sleep mode activated
– Yes
Yes –
– Yes
P22-45 x P
Set
P22-44 x P
Set
P
System
Time
Time
Sleep mode
activated
p = p
System Wake-up
), the motor
set
).
Internal PI controller
Wake up
Yes
–
–
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