Efficient \ grounding of the shield

Best workmanship is to remove the sheath partially and to fix the shield directly onto a metallic rail or surface with a clip or a saddle:

The grounding rail must be close to the cable lead-in in the cabinet wall and should be zinc or nickel plated for proper long term connection.

The rail must be mounted directly on the metallic part of the cabinet. Zinc plated parts and surfaces are preferred inside the cabinets.

Painted surfaces inside the cabinet or aluminium surfaces hinder proper connection.

Also, too long shield wires between the cable and the cabinet wall results in bad EMC data. For the shield wire with a length up to 10 cm, the flexible lead should have minimum 6 mm².

Particularly in installations outside of cabinets, where IP65 is used, the grounding with tube clips can be used:

Wide spread or distant parts of an installation may have different grounding potential if there is not a good metallic connection between in. The voltage difference is low but the equalizing current can be high.

Because of the small cross section, the shield of bus cables is not able to lead large equalizing currents.

Therefore it is mandatory to add an equipotential bonding conductor in these cases with a cross section of at least 25 mm².