Danfoss VLT FC 102 Programming Manual page 212

Parameter Descriptions
Parameter used
Parameter 22-80 Flow Compensation
Parameter 22-81 Square-linear Curve Approxi-
3 3
mation
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 3.27 Number of Pumps
22-80 Flow Compensation
Option:
[0] Disabled
*
[1] Enabled
22-81 Square-linear Curve Approximation
Range:
100 %
*
H (head)
Control Curve
Illustration 3.63 Square-Linear Curve Approximation
210
Function:
Setpoint compensation not active.
Setpoint compensation is active.
Enabling this parameter allows the
flow-compensated setpoint
operation.
Function:
NOTICE
[0 - 100 %]
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).
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VLT HVAC Drive FC 102
Speed at
design point
KNOWN
+
+
+
+
+
+
–
–
–
22-82 Work Point Calculation
Option:
Q ( ow)
Speed at
design point Cascade controller
UNKNOWN
+
+
+
+
–
+
+
+
+
Function:
Example 1
H
(head)
H
DESIGN
Set Point
H
MIN
Par.:
22-83/
Control Curve
22-84/
22-87
Illustration 3.64 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 point and the Q
DESIGN
allows finding point A, which is the
system design working point. The
pump characteristics at this point
should be identified and the
associated speed programmed.
Closing the valves and adjusting
the speed until H
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.
+
–
–
–
–
+
–
–
–
A
Q
(flow)
point
DESIGN
has been
MIN
M0010001