Hi,

I am new in this Forum. I am a spanichs electrical engineer. I have to plan a solar plant in England and I can not find the regulations of the cables for earthing systems. Someone can help me, please?

Greetings,

Lucia

Welcome Lucia!

What you need is section 543 of BS 7671 - the IET Wiring Regulations.

There's no prohibition on using steel as such (in the UK it's common to use the steel armouring of cables as a protective earth), but there are some limitations - e.g. separate conductors of <10mm² have to be copper, and if buried in the ground it might have to be substantially larger than if it were copper.

- Andy.

Assuming the plant is all "Low Voltage", then BS7671: 2008(2011) would typically apply as a minimum. Chapter 54 discussed requirements for Earthing Arrangements and Protective Conductors.

Depending on the size and application, other standards (typically referenced from BS7671) may well apply, e.g. BS7430.

You should also be aware that legally the Construction (Design & Management) Regulations is also likely to apply to the Design as well as Construction & Construction Management related to this work, in addition to other UK legislation.

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Eur Ing Graham Kenyon CEng MIET

Thanks all of you.

I am glad to be in this Forum. It is the first time I see people talking online about electrical engineering and I LIKE

I was not clear with my question. The earthing system is for some transformer stations with 3150KVA trafo, per station. I need to know the norm should I follow (the BS 7671 is indicated for Medium Voltage?). And I don´t mean the steel armouring.

@ AJJewsbury, maybe I was not clear enough. This steel armouring is for mechanical protection not for electrical earthing function. When I mean if I can use steel for earthing systems, I mean the cable or part of the cable used to throught in earth the energy in the case of a earthing fault.

Thank you very much again.

Lucia

Lucia,
We have no reference to Medium Voltage in the UK with respect to standards or legislation at this moment in time.
It is either Low Voltage or High Voltage!

I suspect more info is required,

Difficult to differentiate which "earthing" the question is about from the last post - BS7430, BS7671, and/or HV standards.

Going around my head is the following thought: CDM Regulations (2007), Regulations 4(a) and/or Regulation 11 by virtue of Regulation 12?

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Eur Ing Graham Kenyon CEng MIET

Thank you!