Make the screen connections with the largest possible surface area (cable clamp). This is done by
using the supplied installation devices in the frequency converter.
Cable-length and cross-section:
The frequency converter has been tested with a given length of cable and a given cross-section
of that cable. If the cross-section is increased, the cable capacitance - and thus the leakage current
- may increase, and the cable length must be reduced correspondingly. Keep the motor cable as
short as possible to reduce the noise level and leakage currents.
Details can be found in the relevant Design Guide.
Switching frequency:
When frequency converters are used together with Sine-wave filters to reduce the acoustic noise
from a motor, the switching frequency must be set according to the instruction in Par. 14-01.
Term.
no.
96
97
98
99
U
V
W
PE
1)
Motor voltage 0-100% of mains voltage.
3 wires out of motor
U1
V1
W1
PE
1)
Delta-connected
W2
U2
V2
6 wires out of motor
U1
V1
W1
PE
1)
Star-connected U2, V2, W2
U2, V2 and W2 to be interconnected separately.
1)
Protected Earth Connection
NB!
In motors without phase insula-
tion paper or other insulation re-
inforcement suitable for opera-
tion with voltage supply (such
as a frequency converter), fit a
Sine-wave filter on the output of
the frequency converter.
Illustration 3.70: Compact IP 00 (Chassis), enclo-
sure D3
Illustration 3.71: Compact IP 21 (NEMA 1) and IP
54 (NEMA 12), enclosure D1
VLT
®
Automation Drive FC 300
Operating Instructions High Power
3. How to Install
MG.33.U1.02 - VLT
®
is a registered Danfoss trademark
49
3
