How Often Should You Actually Retest an Electrical Insulating Mat?
I get asked this a lot by plant electricians who've inherited a stack of insulating mats from someone else's procurement decision three years ago, with no test sticker, no paperwork, and no idea whether they're still safe to stand on. The honest answer is you can't tell by looking at one. Rubber doesn't announce when its dielectric properties have started slipping. So here's what the standard actually says, and what tends to happen in practice, which aren't always the same thing. The 12-month rule Under IEC 61111 , mats in Class 1 through Class 4 need an electrical retest at intervals not exceeding 12 months. Not "roughly a year," not "whenever it's convenient", 12 months is the ceiling, and a mat that's gone past it shouldn't be treated as safe for live work regardless of how it looks. Class 0 mats get a bit more leeway. Since they're rated for lower voltage work (up to 1 kV), a thorough visual inspection is general...