Danfoss VLT AQUA Drive FC 200 Programming Manual page 152

Parameter Description
sation operates by adjusting the set-point according to the
output frequency, which is almost proportional to flow,
thus compensating for higher losses at higher flow rates.
H (Required pressure) is the setpoint for closed loop
DESIGN
(PI) operation of the frequency converter and is set as for
closed loop operation without flow compensation.
Illustration 3.55
Parameter used
22-80 Flow Compensation
22-81 Square-linear Curve Approximation
22-82 Work Point Calculation
22-83 Speed at No-Flow [RPM]/22-84 Speed at No-Flow [Hz]
22-85 Speed at Design Point [RPM]/22-86 Speed at Design Point [Hz]
22-87 Pressure at No-Flow Speed
22-88 Pressure at Rated Speed
22-89 Flow at Design Point
22-90 Flow at Rated Speed
Table 3.27 Speed at Design Point Known/Unknown
22-80 Flow Compensation
Option: Function:
[0] Disabled Set-Point compensation not active.
*
[1] Enabled Set-Point compensation is active. Enabling this
parameter allows the Flow Compensated Setpoint
operation.
22-81 Square-linear Curve Approximation
Range: Function:
100 % [0 - 100 %] Example 1:
*
Adjustment of this parameter allows the
shape of the control curve to be adjusted.
0 = Linear
100% = Ideal shape (theoretical).
NOTE
Not visible when running in cascade.
®
VLT AQUA Drive Programming Guide
There are two methods which can be employed,
depending upon whether or not the Speed at System
design Working Point is known.
H (head)
Control Curve
Illustration 3.56
®
MG20O602 - VLT is a registered Danfoss trademark
Speed at Design Point
KNOWN
+
+
+
+
+
+
-
-
-
Speed at Design Point
UNKNOWN
+
+
+
+
-
+
+
+
+
Q ( ow)
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