Current rating standards 69-30 Part IX.

Sustained current ratings for thermosetting insulated cables up to 70mm squared to BS 7211:1989 in mixed groups in painted Steel trunking to   BS 4678 Part 1: 1971.

A method of obtaining current ratings for cables manufactured to BS 7211, installed in painted steel trunking is detailed.  Basic ratings are given together with factors to allow for different fill factors and variations in ambient temperature.  The trunking can contain cables of different sizes and advantage can be taken of cables which carry less than their tabulated rating by allowing other cables to carry more than the tabulated value. The formulae needed for use in a computer aided design system are also provided.  A more detailed explanation of this method of rating cables is given in report 87-0337.  An account of the experimental work carried out to verify the data is given in Report 91-0606.

Price £50 or £300 for a 9 volume set. (Free to AccessRINA subscribers). See also 69-0030 Parts I, II and III. For other 69-0030 series reports see 85-0187, 88-0458, 89-0025, 89-0094 and 89-0135.

Publication author

Mark Coates Principal Consultant, RINA Consulting

Mark Coates joined RINA Consulting (previously ERA) in July 1983. He has worked on projects to determine cable current ratings both experimentally and by theoretical methods and he has carried out assessments of new cable designs, the mechanical performance of cables and joints, failure analysis and life assessment of transmission and distribution equipment.

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