Danfoss vlt aqua Programming Guide

Example 1: Speed at System Design Working Point is known:
From the data sheet showing characteristics for the specific
equipment at different speeds, simply reading across from the
H
DESIGN
point and the Q
DESIGN
point allows us to find point A,
which is the System Design Working Point. The pump charac-
teristics 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 par. 22-81 Square-Linear Curve Approximation
then allows the shape of the control curve to be adjusted infin-
itely.
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 by
means of the data sheet. 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 pressure H
D
at
that flow can be determined. Knowing these two points on the
pump curve, along with H
MIN
as described above, allows the
frequency converter to calculate the reference point B and thus
to plot the control curve which will also include the System de-
sign Working Point A.
VLT
®
AQUA Drive Programming Guide 2. Parameter Description
MG.20.O2.02 - VLT
®
is a registered Danfoss trademark 209
2

Danfoss vlt aqua Specifications

General

Supply Voltage	200-240V, 380-500V, 525-600V
Enclosure	IP20
Features	Energy optimization
Approvals	CE, UL, cUL
Input Voltage Range	200-240V, 380-500V, 525-600V
Output Voltage Range	0 to supply voltage
Protection Features	Overvoltage, Undervoltage, Overcurrent, Short circuit, Ground fault
Communication Interfaces	PROFIBUS
Cooling Method	Air-cooled