IEEE
IEEE 43-2013 is a recommended practice published by the Institute of Electrical and Electronics Engineers for testing the insulation resistance of rotating electrical machinery. It describes how direct-voltage insulation resistance readings are taken on machine windings, how they are corrected and interpreted, and how related quantities such as the polarization index are derived from them.
Editions cited: IEEE 43-2013
The practice applies to the windings of motors and generators, including induction, synchronous and direct-current machines, in both factory and field settings. It covers the purpose of the test, the instruments and connections, the preparation of the machine, the effect of winding temperature and humidity on readings, and the way results are recorded and compared with earlier data from the same machine. It also discusses the factors that make a reading misleading, such as surface contamination, moisture and the type of insulation system. Maintenance engineers, motor repair shops, generator owners and testing firms use it to decide whether a winding is fit to be energized, to track condition over time and to plan drying or rewinding. The pages in this encyclopedia that cite IEEE 43-2013 explain insulation resistance testing in general terms and point the reader to the document itself for the governing methods and recommended values.