Search

Premium Membership

Save 15% on Pro Premium Plan with discount code: UX778 (expires on October 31st). Study specialized LV/MV/HV technical articles and papers.

Review of standardised earthing systems

Electrical power was actually used in 1900. Today electrical installation standards are highly developed and cover all major aspects for a safe installation. In LV, the reference standard is IEC 364 (see appendix no. 1). Standard makers have paid particular attention to the measures to be implemented to guarantee protection of personnel and property (part 4 of the above-mentioned standards).

This concern has resulted in the standardisation of three Earthing Systems. Before reminding readers of these three systems, a concise historical review will certainly be of use.

General

In all industrialised countries, LV networks and loads are earthed for safety reasons to guarantee protection against electric current for persons. The objectives are always the same:

  • fixing the potential of live conductors with respect to the earth in normal operation;
  • limiting voltage between the frames of electrical equipment and the earth should an insulation fault occur;
  • implementing protection devices which remove the risk of Electric Shocks or electrocution of personne;
  • limiting rises in potential due to MV faults.

Influence of MV earthing systems

While the first three objectives listed above fall into the range of LV earthing systems, the fourth has considerable repercussions on safety of personnel and property in LV. Thus, at MV/LV substation level, a MV phase/frame fault or a fault between MV and LV windings may present a risk for equipment and users of the LV network.

In public and industrial MV, except in certain special cases, the neutral is not distributed and there is no protective conductor (PE) between substations or between the MV load and substation. A phase/earth fault thus results in a single-phase short-circuit current limited by earth connection resistance and the presence of limitation impedances, if any (zero sequence generator).

AUTHOR: Schneider Electric experts | Bernard LACROIX, Roland CALVAS

Title:System earthings worldwide and evolutions
Format:PDF
Size:0.25MB
Pages:24
Download:Right here | Video Courses | Membership | Download Updates

System earthings worldwide and evolutions

Premium Membership

Get access to premium HV/MV/LV technical articles, advanced electrical engineering guides, papers, and much more! It will help you to shape up your technical skills in your everyday life as an electrical engineer.
More Information

Leave a Comment

Tell us what you're thinking... we care about your opinion! Please keep in mind that comments are moderated and rel="nofollow" is in use. So, please do not use a spammy keyword or a domain as your name, or it will be deleted. Let's have a professional and meaningful conversation instead. Thanks for dropping by!

  ⁄  seven  =  1

Learn to Design Power Systems

Learn to design LV/MV/HV power systems through professional video courses. Lifetime access. Apply a 15% discount code EAB77 and enjoy learning!

Subscribe to Newsletter

Subscribe to our Weekly Digest newsletter and receive free updates on new technical articles, video courses and electrical guides.