Industrial Automation Magazine India

Cable Design with EMC Solution

Published on : Monday 19-12-2022

Innovative zeroCM® technology prevents EMC interference.

Machines and systems need to be increasingly networked in a smart factory. This increases the requirements with regard to electromagnetic compatibility (EMC). At the SPS trade fair in Nuremberg (Hall 2, Stand 310), LAPP presented a new, innovative EMC solution with zeroCM® technology.

Especially in industrial plants where frequency-converter-controlled motors are used, there is an increase in undesirable currents on the potential equalisation cables or protective earth cables. LAPP therefore set itself the goal of investigating the physical coupling mechanisms within motor connection cables and deriving an innovative cable design from this.

In developing the zeroCM® technology, LAPP took completely new paths. Instead of solving the EMC problem via shielding as usual, the entire cable design of the ÖLFLEX® SERVO FD zeroCM has been rethought. Three phase conductors are now arranged symmetrically and twisted in an inner layer. Additionally, at least one protective conduit is stranded in an outer layer with the opposite stranding bending direction around the three phase conductors in a specific lay length ratio.

The insulation of the conductor is capacitance-optimised and consists of polyethylene, polypropylene or a foam variant. Between the inner layer and the outer layer is a separating fleece. 

The benefits of the invention are obvious. The EMC-optimised cable design is easy to implement and offers the best protection against EMC-related interference currents.

The effectiveness of the innovative cable was confirmed as part of the “PEPA” research project run by the German Federal Ministry for Economic Affairs and Climate Protection. In addition to LAPP, the companies SEW-EURODRIVE, BLOCK, Danfoss, MAGNETEC and the Technical University of Darmstadt are involved in the project. The best values in terms of leakage current at the converter output were achieved by the low-capacitance design of the zeroCM cable. The interference current flowing via a parallel signal cable was also investigated. Here, too, the use of the zeroCM® cable leads to the development of the lowest possible interference currents.

LAPP India Pvt Ltd, Bengaluru. Tel: 080-47405000. Email: [email protected]