Overview

The life of electrical insulation systems (EIS) frequently determines the life of electrical equipment. The life of an electrical insulation system can be affected by electrical, thermal, mechanical or environmental stresses acting either individually or in combination. Intended, estimated or proven service life times are essential parameters for describing the life of electrical insulation systems. In the early days of electrotechnical engineering, life figures were rather vague. The limitation of the life of the insulation under thermal stress was one of the first indicators of the effect of ageing in some equipment in service. As experience in using EIS increased, it was appreciated that there was a need to select specific materials having satisfactory life time at a given temperature, to enable the required service life to be achieved and to allow for the calculation of the thermal capability of equipment. This International Standard establishes the basis for estimating the ageing of electrical insulation systems (EIS) under conditions of either electrical, thermal, mechanical, environmental stresses or combinations of these (multifactor stresses). It specifies the principles and procedures that shall be followed, during the development of EIS functional test and evaluation procedures, to establish the estimated service life for a specific EIS and should be used by all IEC technical committees responsible for equipment having an EIS. The user of this standard may evaluate existing test methods and provide correlation with his equipment. Therefore, the user of this standard is responsible for demonstrating the validity of the existing test method in accordance with the principles of this standard. The determination of the prospective life is a fundamental task when developing and designing an EIS. Estimated service life of an EIS needs to be established for several reasons: - for type testing when introducing a new EIS into production; - for quality assurance of production; - for estimating the life expectancy of new equipment; - for estimating the remaining life for maintenance purposes. "Ageing" focuses on the mechanisms affecting the EIS performance. "Evaluation" links these potential mechanisms by "Analysis" and "Diagnostics" to the design of a specific kind of evaluation test procedure. In addition to a hardcopy version, this new edition of the standard is now also available as an internet version which has been prepared by means of a document management system. This internet version consists of an abridged text version and a multimedia supplement. The aim is to lead the user "interactively" and more quickly to the clause of the document which is of particular interest to him. Flowcharts show the most important paths which might lead to failure of an electrical insulation system, and the informative annex of the standard supports these flowcharts by providing additional information. The MindMap illustration can be interactively used via an internet browser. The browser-based MindMap software by Mindomo is installed on a server of the IEC Central Office in Geneva and is accessible to the public free of charge. The internet address is: http://std.iec.ch/iec60505. (figure) Example: MindMap illustration of the contents of IEC 60505 The interactive MindMap illustration shall be seen as a pilot project in order to develop and distribute standards in a modern, user-friendly online representation in the future. In the future, hardcopy versions will rather be the exception. Interactive illustrations with additional information to figures, literature and video clips and even noise will become increasingly more important in the future. (figure) Example: MindMap illustration of the failure paths under electric load. The responsible committee is K 183 "Bewertung und Qualifizierung von elektrischen Isolierstoffen und Isoliersystemen" ("Evaluation and qualification of electrical insulating materials and systems") (AK 183.0.6 "Verfahren zur Bewertung elektrischer Isolierungen" (WG 183.0.6 "Method for evaluation of electrical insulations")) of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.

Document: references other documents

Document: referenced in other documents

Responsible national committee

DKE/K 183 - Bewertung und Qualifizierung von elektrischen Isolierstoffen und Isoliersystemen