Danfoss VLT AQUA Drive FC 202 Design Manual page 18

Introduction
H
(mwg)
s
60
2 2
50
B
40
30
20
10
0
P
(kW)
shaft
60
50
40
30
20
10
0
Illustration 2.5 Energy Savings in a Pump Application
Distri-
m 3 /
bution
h
% Hours Power Consump-
350 5 438
300 15 1314
250 20 1752
200 20 1752
150 20 1752
100 20 1752
Σ
100 8760
Table 2.5 Energy Savings - Calculation
16
Design Guide
A
1350rpm
C
1050rpm
750rpm
100 200 300
A 1
1350rpm
B 1
1050rpm
C 1
750rpm
100 200 300
Valve regulation Frequency converter
control
Power
tion
A - B kWh A - C
1 1 1 1
42,5 18.615 42,5
38,5 50.589 29,0
35,0 61.320 18,5
31,5 55.188 11,5
28,0 49.056 6,5
23,0 40.296 3,5
275.064
Danfoss A/S © Rev. 06/2014 All rights reserved.
2.8.5 Better Control
If a frequency converter is used for controlling the flow or
pressure of a system, improved control is obtained.
A frequency converter can vary the speed of the fan or
pump, obtaining .
Furthermore, a frequency converter can quickly adapt the
speed of the fan or pump to new flow or pressure
1650rpm
conditions in the system.
Simple control of process (flow, level, or pressure) utilising
the built-in PID control.
2.8.6 Cos φ Compensation
( 3 )
m /h
400
Generally speaking, the frequency converter has a cos φ of
1 and provides power factor correction for the cos φ of the
motor, which means that there is no need to make
allowance for the cos φ of the motor when sizing the
power factor correction unit.
1650rpm
( )
400 m 3 /h
Consump-
tion
kWh
18.615
38.106
32.412
20.148
11.388
6.132
26.801
MG20Z202