Sizing; Choice Of Frequency Converter Size; Which One To Choose? - Danfoss VLT 3000 Series Product Manual

Choice of frequency
converter size
Which one
to choose?
12

Sizing

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