C-Rail

C-Rail is the standard for control cabinet set up

C-Rails are part of the group of mounting rails and is an important standard when setting up a control cabinet. C-Rails are used to mount electric devices properly in the control cabinet. Wiring, set up and maintenance of electrical systems in machines and plants is simplified by systematically putting all devices in order. This reduces cost of work. If wiring is done in a proper way later additions to a plant are easy. C-Rails, top-hat-rails and G-Rails may be used as a combination for mounting.

What is a C-Rail?

The profile or side view of a C-Rail looks just like the letter C. The form is similar to a top-hat-rail with inward bend brims. Another name for C-Rail is C-Profile-Rail.

Many different manufacturers offer C-Rails and different variants of such. Some types of C-Profile-Rails are in accordance to DIN EN 60715 standard available.Other variants are slightly different than the standard and are describes as „similar to DIN EN 60715". There are even types of C-Profile-Rails available which are independent to the standard. C-Profile-Rails may be delivered with or without holes. Some products don not guarantee an even distance of the first hole to the cut edge. To avoid additional expense it should be taken into account when defining mounting holes for a C-Profile-Rail. This is especially important in batch production.

The C-Rail used in a control cabinet differs from the anchor rail used in reinforced concrete construction. The profile is similar but fulfills a different mounting purpose with its welded on anchors sunk into concrete.

Corrosion-Resistant C-Rails

To avoid damage and repair through corrosion when setting up a control cabinet the C-Rail used should be corrosion-resistant. Many types of C-Rails are galvanized or electrogalvanized. Sendzimir galvanizing is a continuous process. The galvanizing process determines the thickness of zinc on the C-Rail. The thickness in turn determines the period of usage. It is to be determined whether the chosen type of coating for the C-Rail is sufficient to withstand the environmental conditions during operation permanently. When drilling or screwing in a C-Profile-Rail the coating might be damaged

C-Rail Standard

The standard for C-Profile-Rails, Top-Hat-Rails and G-Rails is written down in DIN EN 60715 VDE 0660-520:2018-07. The measurements for C-Profile-Rails of the type C 20, C 30, C 40 and C 50 are standardized. The standard also defines which raw materials may be used to make a C-Profile-Rail. Limit deviations of C-Rails are standardized as well. Standards for limit deviations provide securities when mounting or insert accessory parts to the C-Profile-Rail.

Mounting and Shielding on the C-Rail

Bolt clamps should be used to mount cables and lines to the C-Profile-Rail. The bolt clamps used are required to have the fitting foot shape as well as slot width to match the C-Rail. The C-Rail is an essential part of the set up of the OMV-shielding in the control cabinet and wiring. EMV shield clamps are used to connect the cable shield via a C-Rail to the ground potential. Tension has to be kept away from the thin shielding of the cable. Therefore it is mandatory to separate tension release components and components which connect shield and C-Profile-Rail. Several manufacturers offer practical solutions.

The guideline "Control Cabinet set up according to EMV" of the German association for EMV-Technology (DEMVT) contains several notes regarding cable screens, connection of the shield and interruption of the shield within the control cabinet.