IEC 61858 pdf download Electrical insulation systems – Thermal evaluation of modifications to an established wire-wound EIS 5 Evaluation of the change of thickness of an EIM 5.1 Samples Representative samples of the established EIS (the reference EIS) and of the EIS with reduced EIM thickness(es) (the candidate EIS) shall be evaluated in accordance with Clause 1 0. 5.2 Acceptance...