New, rewired and similar installations

This section incorporates questions relating to:

• New or rewired domestic and similar installations
• Alterations and additions in domestic and similar premises

You may notice that some numbers are missing from the Q&A. This is deliberate. The regulations are constantly updated and as questions become out of date, we remove them but do not renumber, as we are aware that visitors to the site will note specific numbers for future reference.

If you have any queries, please contact enquiries@electricalsafetyfirst.org.uk with "Wiring Regulations" as the subject line of your message.

1 FAQs for your term 'concentric'. Clear search

Q1.130 Where split concentric cable complying with either BS 4553 or BS 7870 is run as a sub distribution circuit (sub main) in consumers' premises, must this be recorded as a departure on an electrical certificate, since neither of these standards are included in either Appendix 1 or Appendix 4 of BS 7671?

No.  Appendix 1 includes only those standards which are included in BS 7671 and Appendix 4 is informative not normative.    

Split concentric cable in the LV range complying with either one of two British Standards - BS 4553 and BS 7870 - may be selected, if appropriate to the intended use, without infringing the requirements of BS 7671.      

Split concentric thermoplastic insulated and sheathed cable is listed in Table F4 of IET Guidance Note 1, Selection and Erection as one of the types of cable that can be used for fixed wiring.

Split concentric cables can be used in consumers' premises, provided they comply with the relevant cable standard and are installed in accordance with the requirements of BS 7671.  Some types of terminal and clamping unit are unsuitable for the multiple neutral conductors of split concentric cable.  Consequently, installers must take account of instructions for terminations provided by the manufacturer of the distribution board / consumer unit.  

Regulation number(s):

• 133.1.1
• 510.3
• 511.1