Eaton DC1-12011 Series, Manual

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3 Installation
3.4 Electrical Installation
68
DC1 Frequency Inverter 10/12 MN04020003Z-EN www.eaton.com
3.4.1.2 connection cables
The screened cables between the frequency inverter and the motor should
be as short as possible.
▶ Connect the screening, on both sides and across a large area (360° over-
lap), to the protective earth (PE)
 . The power screening’s protective
earth (PES) connection should be in the immediate proximity of the fre-
quency inverter.and directly on the motor terminal box.
▶ Prevent the screening from becoming unbraided, e.g. by pushing the
opened plastic sheath over the end of the screening or with a rubber
grommet on the end of the screening. As an alternative, in addition to a
broad area cable clip, you can also twist the shielding braid at the end
and connect to protective ground with a cable clip. To prevent EMC
interference, this twisted screening connection should be as short as
possible (
￫ Figure 39).
Figure 38: Screened connection cable
Figure 39: Connection with twisted cable screen
Recommended value for twisted cable shielding:
b
≧ 1/5 a
Screened, four-wire cable is recommended for the motor cables. The green-
yellow line of this cable connects the protective ground connections from the
motor and the frequency inverter and therefore minimizes the equalizing cur-
rent loads on the shielding braid.
The following figure shows the construction of a four-wire, screened motor
line (recommended specifications).
15 mm
(0.59’’)
PES
U/T1 V/T2 W/T3
a
b
PES