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GENERAL EMC - HARMONICS - MAINS INTERFERENCE
Installation guide Powerdrive MD Smart Equipment
5704 en - 2021.10 / b
4.5 - Basic precautions for installation
These should be taken into account when wiring the
Powerdrive MD Smart
and the external components. In
each paragraph, they are listed in decreasing order of effect
on correct operation of the installation.
4.5.1 - Wiring inside the cabinet
- Separate as far as possible control cables and power cables
(Do not run them in the same cable ducts).
- For control cables, use shielded twisted cables and connect
the shield to the drive grounding bracket.
Shielding bracket
Shielding bracket for optional modules
4.5.2 - Wiring outside the cabinet
4.5.2.1 - Control wiring
If the control cable needs to run outside the cabinet, use a
shielded cable and connect the shield to the grounding
bracket.
4.5.2.2 - Power wiring
• Connect the motor earth terminal directly to that of
the drive.
Never use shielded single-core cables.
Use shielded 3-core cables with symmetrical conductors
for protective earthing as indicated below.
U
W
V
PE
PE
PE
Shielding
A separate PE protective conductor is mandatory if the
conductivity of the cable shielding is less than 50% of the
conductivity of the phase conductor.
- The shielding must be connected at both ends: drive end
and motor end (connected round the whole circumference).
- In the second industrial environment, the shielded motor
power supply cable can be replaced by a 3-core + earth
cable placed in a fully enclosed metal conduit (metal cable
duct for example). This metal conduit must be mechanically
connected to the electrical cabinet and the structure
supporting the motor.
If the conduit consists of several pieces, these should be
interconnected by braids to ensure earth continuity. The
cables must be positioned and held in a cloverleaf formation
in the conduit.
U
W
V
PE
U
W
V
PE
EMC braid
Clamp
- There is no need to shield the power supply cables between
the mains supply and the drive.
- Isolate the power cables from the control cables. The power
cables must intersect the other cables at an angle of 90°.
- Isolate sensitive elements (probes, sensors, etc) from metal
structures which may be shared by the motor support.
- The motor cables and network power cables should not be
routed side by side in the same channel to reduce proximity
couplings.
