ELECTRICAL CABLING AND CONNECTIONS
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6
6.1.6
Earthing of power unit
The mains cables are connected to the protective earth of the switchgear enclosure.
We recommend to connect the motor cables to the common PE of the cabinet/cabinet system.
For earthing of the drive itself, use the earthing terminal on the drive mounting plate (see Figure 6-4).
Figure 6-4. Earthing terminal on mounting plate
6.1.7
Installation of ferrite rings (option) on the motor cable
Slip only the phase conductors through the
window; leave the cable screen below and
outside the rings, see Figure 6-5.
Separate the PE conductor. In case of
parallel motor cables, reserve an equal
amount of ferrite rings for each cable and
feed all the phase conductors of one cable
through one set of rings. The Vacon
delivery includes fixed sets of ferrite rings.
When ferrite rings are used to attenuate
the risk of bearing damages, the number
of ferrites has to be 6…10 for a single
motor cable and 10 per cable when the
motor is supplied with parallel cables.
Note! The ferrite rings are only additional
protection. The basic protection against
bearing currents is an insulated bearing.
Figure 6-5. Installation of ferrite rings