CG Emotron VFX Series, Instruction Manual

Page: 33 / 268

CG Drives & Automation, 01-5326-01r5 Installation 29
Fig. 40 Wiring example showing Protective earth, Motor earth
and Brake Resistor connection
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
14. Use symmetrical shielded cable; three phase conduc-
tors and a concentric or otherwise symmetrically con-
structed PE conductor, and a shield.
• PE conductor cross-sectional area shall for phase cable
size < 16 mm
2
(6 AWG) be >10 mm
2
Cu (16 mm2 Al)
or use a second PE conductor with same area as original
PE conductor.
For cable size above 16mm
2
(6 AWG) but smaller or
equal to 35mm
2
(2 AWG) the PE conductor cross-sec-
tional 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, +75
°
C (167
°
F) or higher.
• Dimension the cables in accordance with the rated cur-
rent of the motor.
• 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. 42, 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. 31, to Fig. 39.
Table 13 Mains and motor connections
L1,L2,L3
PE Mains supply, 3 -phase
Safety earth (protected earth)
U, V, W
Motor earth
Motor output, 3-phase
DC-,DC+,R
Brake resistor, DC-link
connections (optional)
NOTE: The Brake and DC-link Terminals are only
fitted if the DC+/DC- option or Brake Chopper Option
is built-in.
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.