ABB DCS 400, Руководство пользователя, Страница: 111 / 192

II K 5-11
Installation
14 Power cables
without screens
If a screen is not necessary (see 13 ) the armature current cable
must be a four-wire cable because two wires are needed as con-
ductors for the parasitic RF currents from the motor to the RF filter
in the cubicle. The unscreened field current cable
F must be in-
stalled directly along the armature cable A as shown in figure 5.2-
5. A 2-wire cable is sufficient.
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Figure 5.2 - 5 Cross-sectional view of arrangement of field current
cable F and armature cable A
The arrangement according to 26 has been tested with a 20 m long
motor cable with the result that the conducted emission require-
ments are fulfilled.
If the connections to the armature are made from single-wire ca-
bles, especially if n parallel wires are necessary for higher currents,
then n+1 PE cables must be arranged together with them on a ca-
ble rail as shown in principle by the figure 5.2-6 with n=4.
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Figure 5.2 - 6 Cross-sectional view of arrangement of field current
cable F and armature cable A for higher currents
15 Placement of
cables within
the cabinet
All power cables which are directly connected with the converter
(U1, V1, W1, C1, D1) must either be screened or be kept close to-
gether and close to the mounting plate and separate from all other
cables (L1, L2, L3 included) and especially from unscreened signal
cables. A recommended separation possibility is to place these
power cables at the rear side of the mounting plate. If direct cross-
ings of "polluted" cables and others, especially signal cables, are
inevitable then they must be made rectangular.
16 Placement of
cables outside
the cabinet
The power cables must be arranged parallel and close together,
see drawings in
14 . The speed feedback must be screened and
placed directly along the power cables to the motor if the housing
of the tacho machine is electrically connected with the housing of
the motor. If the housing of the tachometer or the encoder is insu-
lated from the motor then a distance between the power and signal
cables is advantageous.