VEM VEMoDRIVE VSI 2.0 HD, Instruction Manual

Page: 29 / 244

CG Drives & Automation, 01-5326-01r3b IInstallation 27
3.2.2 Motor cables
To comply with the EMC emission standards the AC drive
is provided with a RFI mains filter. The motor cables must
also be screened and connected on both sides. In this way a
so-called “Faraday cage” is created around the AC drive,
motor cables and motor. The RFI currents are now fed back
to their source (the IGBTs) so the system stays within the
emission levels.
Recommendations for selecting motor
cables
• Use screened cables according to specification in table
12. Use symmetrical shielded cable; three phase
conductors and a concentric or otherwise symmetrically
constructed PE conductor, and a shield.
• PE conductor cross-sectional area shall for cable size
< 16mm
2
(6 AWG) be equal to the used phase
conductors, for cable size above 16mm
2
(6 AWG) but
smaller or equal to 35mm
2
(2 AWG) the PE conductor
cross-sectional area shall be at least 16mm
2
(6 AWG).
For cables >35mm
2
(2 AWG) the PE conductor cross-
sectional area should be at least 50% of the used phase
conductor.
When the PE conductor in the used cable type is not in
accordance with the above mentioned cross-sectional
area requirements, a separate PE conductor should be
used to establish this.
• Use heat-resistant cables, +60
°
C (140
°
F) or higher.
• Dimension the cables and fuses in accordance with the
nominal output current of the motor. See table
7, page
.
• Keep the motor cable between AC drive and motor as
short as possible.
• The screening must be connected with a large contact
surface of preferable 360
°
and always at both ends, to
the motor housing and the AC drive housing. When
painted mounting plates are used, do not be afraid to
scrape away the paint to obtain as large contact surface as
possible at all mounting points for items such as saddles
and the bare cable screening. Relying just on the
connection made by the screw thread is not sufficient.
• The litz ground connection, see fig. 37, is only necessary
if the mounting plate is painted. All the AC drives have
an unpainted back side and are therefore suitable for
mounting on an unpainted mounting plate.
Connect the motor cables according to U - U, V - V and
W - W, see Fig. 28, to Fig. 34 .
Switches between the motor and the
AC drive
If the motor cables are to be interrupted by maintenance
switches, output coils, etc., it is necessary that the screening
is continued by using metal housing, metal mounting plates,
etc. as shown in the Fig. 37.
Fig. 36 Screen connection of cables.
WARNING!
The Brake Resistor must be connected
between terminals DC+ and R.
WARNING!
In order to work safely, the mains earth must
be connected to PE and the motor earth
to .
NOTE: It is important that the motor housing has the
same earth potential as the other parts of the machine.
NOTE: The terminals DC-, DC+ and R are options.
Screen connection
of signal cables
PE
Motor cable
shield connection
9(0R'ULYH 96, 9(0 U