TECO F33 Series, Instruction Manual, Page: 19 / 192

16 Installation
3.2.2 Motor cables
To comply with the EMC emission standards the varia-
ble speed 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 cre-
ated around the VSD, 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 7. Use symmetrical shielded cable; three
phase conductors and a concentric or otherwise
symmetrically constructed PE conductor, and a
shield.
• When the conductivity of the cable PE conductor is
<50% of the conductivity of the phase conductor, a
separate PE conductor is required.
• Use heat-resistant cables, +60°C or higher.
• Dimension the cables and fuses in accordance with
the nominal output current of the motor. See table
49, page 165.
• Keep the motor cable between VSD and motor as
short as possible.
•
The screening must be connected with a large con-
tact surface of preferable 360
°
and always at both
ends, to the motor housing and the VSD 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. 24, is only nec-
essary if the mounting plate is painted. All the varia-
ble speed 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. 20 and Fig. 21.
Switches between the motor and the
VSD
If the motor cables are to be interrupted by mainte-
nance 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. 23.
Fig. 24 shows an example when there is no metal
mounting plate used (e.g. if IP54 variable speed drives
are used). It is important to keep the “circuit” closed, by
using metal housing and cable glands.
Fig. 22 Screen connection of cables.
Pay special attention to the following points:
• If paint must be removed, steps must be taken to
prevent subsequent corrosion. Repaint after making
connections!
• The fastening of the whole variable speed drive
housing must be electrically connected with the
mounting plate over an area which is as large as
possible. For this purpose the removal of paint is
necessary. An alternative method is to connect the
variable speed drive housing to the mounting plate
with as short a length of litz wire as possible.
• Try to avoid interruptions in the screening wherever
possible.
• If the variable speed drive is mounted in a standard
NOTE: The Brake and DC-link Terminals are only fitted if
the 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.
Screen connection
of signal cables
PE
Motor cable
shield connection