Werner Turck GmbH & Co. KG TNM30 User Manual

D101583 0207

Avoid the installation of sources of interference which occur 
primarily due to switched inductances.

Interference is generated primarily by relays, contactors, fluorescent 
lamps in the switch cabinet and valves, and can be avoided by the 
use of RC combinations, freewheel diodes etc. This also avoids 
inductive interference in the cables which are laid parallel to the coil 
cables.

If the system sections are subject to a different design and different 
voltage levels result, potential differences can result between the 
different sections of the system. Equalization currents then flow via 
signal cables (potential equalization should not be confused with a 
protective earth).

Therefore correctly implemented potential equalization is essential.
The following points should be observed:

„

The potential equalization cable must have a sufficient cross-
section (min. 10 mm

2

).

„

The distance between signal cables and the respective potential 
equalization cable must be as small as possible.

„

A stranded conductor must be used.

„

If the potential equalization cables are connected to the central 
potential equalization bars, the power components and the non-
power components must be combined.

Signal cables must be shielded in order to avoid coupled 
interference. Even though the best shielding effect when laying the 
cables is achieved by using steel ducts, the use of cables with 
braided shields is usually sufficient. Decisive for the effect of the 
shield in both cases is however the correct connection, as a non-
connected or incorrectly connected shield has no effect.