Are all double-layer tools of "Eхpert" series subjected to obligatory check every year?
Under the order of the Russian Ministry for Energetics #261 of 30th of June 2003, the tools with double-layer insulation should be visually checked every 6 months (par. 1.4.3). In case the second layer becomes visible during usage, it should be removed immediately. So there is not a requirement to check double-layer VDE tools under voltage every year.