16th Edition (reference only) – NOW superseded by the 17th Edition IEE Regulations.

chapter 5

chapter 6

Cables, conduits and trunking
  4.1 - Cable insulation materials 4.4 - Cable supports, joints and terminations
  4.2 - Cables 4.5 - Cable enclosures
  4.3 - Cable choice 4.6 - Conductor and cable identification

4.3.10 - Special formulas for grouping factor calculation

In some cases the conductor sizes where cables are grouped and determined by the methods shown in {4.3.9} can be reduced by applying some rather complex formulas given in [Appendix 4].

Whilst it is true that in many cases the use of these formulas will show the installer that it is safe for him to use a smaller cable than he would have needed by simple application of correction factors, this is by no means always the case. There are many cases where their application will make no difference at all. Since this book is for the electrician, rather than for the designer, the rather complicated mathematics will be omitted.







Return to top of page

Extracted from The Electricians Guide Fifth Edition
by John Whitfield

Published by EPA Press Click Here to order your Copy.

Click here for list of abbreviations