IEC 61478-2003 pdf – Live working – Ladders of insulating material.
1 Scope This International Standard is applicable to fully insulating spliced or hook ladders with extension or having a combination of insulating and conductive sections and used for live working on a.c. or d.c. electrical installations at 1 000 V and above for a.c. and 1 500 V and above for d.c. The ladders are classified functionally as Category 1 and Category 2. This standard concerns only ladders made of synthetic material. These ladders are used, to provide access, generally on overhead line structures and to facilitate live working, either hot stick, barehanded or a combination of both. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050(151):2001, International Electrotechnical Vocabulary (IEV) – Chapter 151: Electrical and magnetic devices IEC 60212:1971, Standard conditions for use prior to and during the testing of solid electrical insulating materials IEC 60417 (all parts) [DB-2000] 1) , Graphical symbols for use on equipment IEC 60743, Live working – Terminology for tools, equipment and devices IEC 60855:1985, Insulating foam-filled tubes and solid rods for live working IEC 61235:1993, Live working – Insulating hollows tubes for electrical purposes IEC 61318:1994, Live working – Guidelines for quality assurance plans ISO 2859-1:1999, Sampling procedures for inspection by attributes – Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection
3 Definitions For the purpose of this International Standard, the following definitions apply. 3.1 section unit of a ladder consisting of a minimum of three rungs 3.2 base section first element of a ladder designed to support other sections NOTE It may be the highest or lowest element of a ladder . 3.3 spliced ladder ladder constructed of sections that are made of metal or synthetic material and spliced together [IEC 60743, 9.1.3] 3.4 insulating hook ladder insulating ladder equipped to one end with permanent or removable hooks which can be rigid or can rotate [IEC 60743, 9.1.4] 3.5 insulating ladder extension additional insulating section which can be fixed to an insulating hook ladder or another ladder extension [IEC 60743, 9.1.5] 3.6 support bracket device designed to be fastened to any level of the structure and supporting the load of the spliced ladder NOTE It may also be fitted to the structure between spliced ladder sections.
3.7 cradle device designed to hold the ladder at a fixed distance from the structure on which it is positioned 3.8 fixing system link device designed to hold the ladder firmly to the structure 3.9 connecting device constructive arrangement allowing the connection of two ladder extensions or one ladder extension and one base section 3.10 adjustable foot device inserted on a height-adjustable base section in order to adjust a level difference between the two ladder feet 3.11 type test test of one or more devices made to a certain design to show that the design meets certain specifications 3.12 routine test test to which each individual device is subjected during or after manufacture to ascertain whether it complies with certain criteria 3.13 sampling test test on a number of devices taken at random from a batch 3.14 acceptance test contractual test to prove to the customer that the device meets certain conditions of its specification [IEV 151-16-23] 4 Classification 4.1 Category 1 Category 1 ladders are designed to be attached to overhead line structures to allow climbing. These ladders are positioned vertically on the structures with special cradles and they are attached by fixing systems to prevent the ladder from moving on the structures. The ladder may rest either on the ground or on a special platform fitted to the structure. These ladders shall comprise a minimum of one insulating section. They may be extended by the use of additional insulating or conductive sections suitably interlocked. Category 1 ladders are restricted to voltages up to and including 36 kV.