Nidec Leroy-Somer Powerdrive MD Smart, Руководство по интеграции

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CONNECTIONS - CABLING
Powerdrive MD Smart Integration Guide
5751 en - 2021.10 / e
CONNECTIONS
CABLING
4.1.2.2 - Shielding
Shielding is necessary to mitigate (dampen) magnetic, electric or electromagnetic disturbance fields. Use dense-braided shielded
cables where possible (coverage rate) > 80%). Avoid using shielded ribbon cables.
Generally:
• Separate the control and power cables as much as possible (do not run them through the same pins).
• Signal cables integrated into the motor cable (i.e., the motor’s thermal probe, the motor’s brake) receive significant disruptions
through the cable capacity. The shielding of these signal cables shall be connected to the ground near the motor cable to prevent
the propagation of this parasitic current in the control system.
• The shielding of power conductors provides a preferred path for common mode currents to return to their original point of origin
without dispersing into other possible paths (equipotential conductors, piping, building structures, etc.). It significantly reduces
the levels of electromagnetic emissions conducted and radiated. For this reason, the use of shielded cables between variable
speed drive and motor is imperative to ensure compliance with EMC emission standards (IEC 61800-3, etc.). Shielded cables
also limit the shaft tension and the risk of bearing damage.
• the cable shielding must be connected to ground potential at both ends. Only a connection at both ends allows a good immunity
in the high frequency range. In exceptional cases, shielding can only be connected to the ground potential at one end. Only low
frequencies will be amortized. The connection of one end of the shielding may be useful when:
- It is not possible to install an equipotentiality cable.
- It is not necessary to transmit analogue signals (a few mVs or μA).
The disruptive currents are derived to the ground through the shielding bar connected by a conductive connection to the housing. In
order to prevent these derived currents from becoming sources of disturbance themselves, it is essential to make a low impedance
connection to the protection conductor.
For more details, please refer to the Guide to Good Practices ref.5626, which can be downloaded from www.leroy-somer.com.
- For control cables, use shielded twisted cables and connect the shielding to the collar of the MD3CTL shielding module.
A shielding connection calliper comes with each option. To secure it, screw the calliper over the shielding collars of the control
cables (the rightmost shielding collar must be removed).