Danfoss VLT DriveMotor FCP 106, Programming Manual

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Parameter used
Speed at design point
KNOWN
Speed at design point
UNKNOWN
Parameter 22-80 Flow Compensation + +
Parameter 22-81 Square-linear Curve Approximation + +
Parameter 22-82 Work Point Calculation + +
Parameter 22-83 Speed at No-Flow [RPM] / parameter 22-84 Speed at No-
Flow [Hz]
+ +
Parameter 22-85 Speed at Design Point [RPM] / parameter 22-86 Speed at
Design Point [Hz]
+ -
Parameter 22-87 Pressure at No-Flow Speed + +
Parameter 22-88 Pressure at Rated Speed - +
Parameter 22-89 Flow at Design Point - +
Parameter 22-90 Flow at Rated Speed - +
Table 4.14 Speed at Design Point Known/Unknown
22-80 Flow Compensation
Option: Function:
[0]
*
Disabled Setpoint compensation not active.
[1] Enabled Setpoint compensation is active. Enabling this
parameter allows the flow-compensated setpoint
operation.
22-81 Square-linear Curve Approximation
Range: Function:
100 %
*
[0 - 100 %]
NOTICE
Not visible when running in cascade.
Example 1
Adjustment of this parameter allows the
shape of the control curve to be adjusted.
0=Linear
100%=Ideal shape (theoretical).
Control Curve
(head)
(flow)
H
Q
130BA388.11
100%
P22-81 0%
Illustration 4.21 Square-Linear Curve Approximation
22-82 Work Point Calculation
Option: Function:
Example 1
A
130BA385.11
P22-85/22-86
Control Curve
H
MIN
H
DESIGN
Set Point
n
RA
TED
_
f
RA
TED
n
DESIGN
-
f
DESIGN
Q
(flow)
H
(head)
Par.:
22-83/
22-84/
22-87
Illustration 4.22 Speed at System Design
Working Point is Known
From the datasheet showing characteristics for the
specific equipment at different speeds, simply
reading across from the H
DESIGN
point and the
Q
DESIGN
point allows finding point A, which is the
system design working point. The pump character-
istics at this point should be identified and the
associated speed programmed. Closing the valves
and adjusting the speed until H
MIN
has been
achieved allows the speed at the no-flow point to
be identified.
Adjustment of
parameter 22-81 Square-linear Curve
Approximation then allows the shape of the
control curve to be adjusted infinitely.
Example 2
Speed at system design working point is not
known: Where the speed at system design
working point is unknown, another reference point
on the control curve needs to be determined
based on the datasheet. By looking at the curve
for the rated speed and plotting the design
pressure (H
DESIGN
, Point C), the flow at that
pressure, Q
RATED
, can be determined. Similarly, by
plotting the design flow (Q
DESIGN
, Point D), the
Parameters Programming Guide
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