Danfoss VLT series

The laws of proportionality
This figure describes the dependence of flow, pressure and power consumption on rpm.
Q = Flow P = Power
Q
1
= Rated flow P
1
= Rated power
Q
2
= Reduced flow P
2
= Reduced power
H = Pressure n = Speed regulation
H
1
= Rated pressure n
1
= Rated speed
H
2
= Reduced pressure n
2
= Reduced speed
Flow :
Q
1
Q
2
=
n
1
n
2
Pressure :
H
1
H
2
=
(
n
1
n
2
)
2
Power :
P
1
P
2
=
(
n
1
n
2
)
3
2. Introduction to the VLT HVAC Drive VLT
®
HVAC Drive Design Guide
20 MG.11.B4.22 - VLT
®
is a registered Danfoss trademark.
2