Screening of cables:
Avoid installation with twisted screen ends (pigtails). They spoil the screening effect at higher frequencies. If it is necessary to break the screen to install
a motor isolator or motor contactor, the screen must be continued at the lowest possible HF impedance.
Connect the motor cable screen to both the de-coupling plate of the frequency converter and to the metal housing of the motor.
Make the screen connections with the largest possible surface area (cable clamp). This is done by using the supplied installation devices within the
frequency converter.
Cable-length and cross-section:
The frequency converter has been EMC tested with a given length of cable. Keep the motor cable as short as possible to reduce the noise level and
leakage currents.
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
Switching Frequency
.
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 insulation paper or other in-
sulation reinforcement suitable for operation with volt-
age supply (such as a frequency converter), fit a Sine-
wave filter on the output of the frequency converter.
3 How to Install
VLT AQUA High Power Operation Instructions
50
MG.20.P3.02 - VLT
®
is a registered Danfoss trademark
3
