EN 61857-1:2009

INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 General information
  4.1 Overview of test procedure
  4.2 Basis of evaluation and qualification
  4.3 Specific requirements
5 Test objects
  5.1 General
  5.2 Description
  5.3 Number of test objects
6 Test procedures
  6.1 General
  6.2 Initial screening tests
  6.3 Thermal ageing
  6.4 Prediagnostic mechanical stress
  6.5 Other prediagnostic conditioning
  6.6 Moisture exposure
  6.7 Dielectric diagnostic tests
  6.8 Other diagnostic tests
7 Analyzing, reporting and classification
  7.1 End-point criterion
  7.2 Method of determining life
  7.3 Extrapolation of data
  7.4 Report of results
Bibliography
Annex ZA (normative) - Normative references to international
                       publications with their corresponding
                       European publications

IEC 61857-1:2008 specifies a general test procedure for the thermal evaluation and qualification of electrical insulation systems (EIS) and establishes a procedure that compares the performance of a candidate EIS to that of a reference EIS. This standard is applicable to existing or proposed EIS used in electrotechnical products with an input voltage of up to 1 000 V where the thermal factor is the dominating ageing factor. This third edition cancels and replaces the second edition published in 2004, and constitutes editorial revisions to make this standard compatible with Parts 21 and 22.