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Railway earthing - technical information

Short-circuit current strength

Which materials and cross-sections are sufficient?

To obtain approval from DB Netz AG, it must be proven that all components are short-circuit-current-proof (RIL 997.0205A01).

The following parameters are used:

Ik’’ ≤ 25 kA: test current of 25 kA, duration of 100 ms
Ik’’ > 25 kA: test current of 40 kA, duration of 100 ms

Short-circuit current ≤ 25 kA > 25 kA
Earthing conductors laid in open space Cu 50 mm2
NYY-O
Fe 95 mm2
Steel cable
Cu 70 mm2
NYY-O
Fe 120 mm2
Steel cable
Earthing conductors laid in concrete Cu 70 mm2
NYY-O or H07V-K
Fe 120 mm2 Cu 95 mm2
NYY-O or H07V-K
Fe 200 mm2

These points must be observed:

Bare steel conductors, embedded in concrete

  • Structural reinforcement steels must not be used as earthing conductors.
  • Statically required components must not be used as earthing conductors.
  • Welding earthing parts to the structural reinforcement is not permitted.


When laid in concrete

  • Parts of the earth-termination system must be checked before concreting.
    This is done by an approved inspector or qualified electrician.
    This partial acceptance must be documented.
  • For series-produced precast concrete parts, the check is carried out during technical acceptance.
  • In case of individual concrete production, the check is carried out directly at the manufacturer's premises before concreting.


Concrete-embedded joints 

  • Concrete-embedded joints must generally be welded to be short-circuit-current-proof. The defined welding seam lengths and thicknesses must be observed:

    Welding seam length
    In case of short-circuit currents ≤ 25 kA at the installation point, a length of at least 2 x 30 mm is required - in case of short-circuit currents > 25 kA, a length of at least 2 x 45 mm is required.

    Welding seam thickness
    To avoid a reduction in cross-section, an effective welding seam thickness of 4 mm is required.
Contact

Have you got any? Contact us.

DEHN INDIA Pvt. Ltd.

Phone: +91 124 4007680

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