Cable
headed
towards
DR2020
4.3. Electrical installation and thermal sizing
4.3.1. Safety and general instructions for the board
WARNING
When the drive is operating, there is a risk of death, serious injury or serious material damage
AVERTISSEMENT
Lorsque l'entrainement est en marche, il existe un risque de mort, blessures graves ou dommages
matériels importants.
between
DM2020
MAR2-E-191
34
Fig 4.1 Diagram of the distribution board with components for a servo system
Special attention must be paid to the earthing, shielding, use of the
filter
to reduce or stop particularly steep
voltage edges (resulting from PWM modulation) that can generate signi
fi
cant unwanted current through electrostatic
couplings and earthing systems. These voltage edges can also generate high frequency irradiated disturbance, above all
through the motor cable.
Filters installed on the network will reduce conducted disturbance: See section “2.2.3.1. Filters” for recommended models.
There are usually two types of problem
s
regarding earthing in boards:
• The (high frequency) EMC earth comprising a portion of an unpainted metal wall, where the drives are positioned
,
and the
fi
lters, creating an electrical contact that is adequate for attenuating high frequency disturbance.
• Protective earth (PE) according to EN60204-1, using conductors with a minimum cross-section equal to 10 mm
2
.
A
ll power and control cables must be shielded except for cables running from the mains to the power
fi
lter; the shielding of these
is linked to the layout of the board, and may not be necessary.
Usually the shield must be connected at each end. In some cases, control cable shielding may be connected at one end only, to
eliminate network noise that could interfere with the control signal.
