12
MG.30.A7.02 - VLT
®
is a registered Danfoss trademark
Choice of frequency
converter size
The frequency converter must be chosen
on the basis of the actual motor current I
M
at maximum load of the plant.
The rated continuous output current I
VLT,N
must be equal to or higher than the
required motor current.
Sizing
Example:
In a heating plant (quadratic load) the
pump motor is a 7.5 kW, 3 x 380 V, which
at max. load takes up 14 A.
Choose a VLT
®
3008 which can supply
16 A (I
VLT,N
) continuously.
Mains: 3 x 200/220/230 V and 3 x 220/230/240 V (see technical data)
Which one
to choose?
The
VLT
®
types larger
than 3004 (3008 at 500 V) have
a higher output when using
quadratic load,
referred to as VT load
(variable torque).
Some technical specifications
might change from
CT to VT mode (e.g. the max.
motor cable length
decreases).
: Intermittent operation
: In continuous operation some specifications might change
CT
VT
CT
VT
CT
VT
Typical shaft
Constant output
Constant output
VLT
®
type
output
current I
VLT.N
power at 230 V
[kW]
[A]
[kVA]
3002
1.1
5.4
2.1
3003
1.5
7.8
3.1
3004
2.2
10.5
4.2
3006
4.0
5.5
19
25
7.6
10.0
3008
5.5
7.5
25
32
10.0
12.7
3011
7.5
11
32
46
12.7
18.3
3016
11
15
46
61
18.3
24.3
3022
15
22
61
88
24.3
35.1
3032
22
30
80
104
31.9
41.4
3042
30
37
104
130
41.4
51.8
3052
37
45
130
154
51.8
61.3
CT: Constant torque
VT: Variable torque (quadratic load)
