Danfoss Metasys N2 Design Guide

175HA209.11
60
50
40
30
20
10
H
s
0 100 200 300 400
(mwg)
B
C
A
750rpm
1050rpm
1350rpm
1650rpm
0
10
20
30
(kW)
40
50
60
200100 300
(m
3
/h)
(
m
3
/h)
400
750rpm
1050rpm
1350rpm
1650rpm
P
shaft
C
1
B
1
A
1
Illustration 5.12 Energy Savings in a Pump Application
5.3.2 Using a Drive for Better Control
If a drive is used for controlling the ow or pressure of a
system, improved control is obtained. A drive can vary the
speed of the fan or pump, obtaining variable control of
ow and pressure utilizing the built-in PID control.
Furthermore, a drive can quickly adapt the speed of the
fan or pump to new ow or pressure conditions in the
system.
Cos φ compensation
Typically, the VLT
®
HVAC Drive has a cos φ of 1 and
provides power factor correction for the cos φ of the
motor, which means there is no need to make allowance
for the cos φ of the motor when sizing the power factor
correction unit.
Star/delta starter or soft starter not required
When larger motors are started, it is necessary in many
countries to use equipment that limits the start-up current.
In more traditional systems, a star/delta starter or soft
starter is widely used. Such motor starters are not required
if a drive is used. As illustrated in Illustration 5.13, a drive
does not consume more than rated current.
Full load
% Full-load current
& speed
500
100
0
0 12,5 25 37,5 50Hz
200
300
400
600
700
800
4
3
2
1
175HA227.10
1
VLT
®
HVAC Drive FC 102
2 Star/delta starter
3 Soft starter
4 Start directly on mains
Illustration 5.13 Current Consumption with a Drive
Product Features Design Guide
MG16C302 Danfoss A/S © 11/2017 All rights reserved. 29
5 5

Danfoss Metasys N2 Specifications

General

Brand	Danfoss
Model	Metasys N2
Category	DC Drives
Language	English