Cable routing systems

Inclusion of the cable routing systems and metal service poles in the service measures

Specifications for protective measures
If there is a fault, touchable metallic parts must not carry voltage. For this reason it is necessary to carry out appropriate safety measures. These are specified in the currently valid standards. EN 50085-1 and EN 50085-2-1 apply to the setup of the cable routing system, whilst the erection regulations DIN VDE 0100 Parts 410 and 540 apply to the installation (protection measure against dangerous shock currents).

Different installation types in the European standard
The European standard EN 50085-1 takes different installation types into account, as they are used in different countries within the EU. Whilst only equipotential bonding testing was previously required for installation trunking systems, now the listed component standards also require protective conductor functions. This is because, in some countries, it is possible to route insulated cable in trunking.

All the metallic components must be included
EN 50085-1 requires that all the metallic components must be included in the protective measures. The manufacturers must carry out the appropriate tests and document them. OBO installation trunking is also tested and certified by an external testing office – that of the VDE.

Testing the effectiveness by the installation engineers
The erector (installation engineer) must test the effectiveness of the protection measure in accordance with DIN VDE 0100 Part 610 after completion. Ensure the tightening torque of the contact screws on the earthing terminals and the proper mounting of the couplings.

Continuous protection measures
If the trunking is interrupted at a wall penetration, then continuation of the protective measures is required, as, in this case, the trunking is a foreign, conductive part, which spreads through different areas of a building.
With aluminium device installation trunking, the connection between the bases is created using the coupling. The connection between the covers and the device installation trunking is made using the self-contacting cover. This guarantees continuous protection without any additional wiring.
With the LKM metal cable trunking, a connection is made between the cover and the base without an additional earthing cable. The connection between the bases is made via the joint connector. Important: powder-coated metallic covers do not count as mixed construction and are thus not considered as insulating! They should therefore be included in the protective measure. The sheet-steel separating retainers are self-contacting. From the aspect of capacitive coupling and the possible static coupling, the inclusion of metallic device installation trunking covers is included in the planning of the protective conductor function. The shielding measure reduces electro-smog and generally achieves improved EMC protection. Protective conductor connections should be permanent. If there is a change to the system, e.g. for retro-installations, it is important to guarantee the maintenance of the protection functions.