Perspectives: Field Notes

Think More About Electrical Area Classification

Questions highlight uncertainties about appropriate actions

By Dirk Willard, Contributing Editor
Feb 22, 2017

I was building skids for a process in Canada that involved a combustible dust and a flammable liquid; however, my customer wasn’t concerned that we were using general-purpose equipment. Nor was the company owner, the project manager or even the process lead — who should have known better. As an expert in electrical area classification (EAC), I was wondering where to begin with less than 90 hours available for the project. I endured questions like: “Can’t I just add a high temperature cut-off?” Nope, the solution has to be intrinsic. And “Why can’t we move the equipment away from the explosive hazard so we don’t have to buy that expensive intrinsically safe stuff?” “Sure, just move it to Cleveland,” I replied in exasperation. As I emphatically made clear, we needed to re-design the powder feed system and the skids with equipment and instruments suitable for the fire hazard. When we were building the skids, there were two piles in the shop: one for NFPA-rated Class I, Div. 1 and 2 equipment, and another for general-purpose items destined to be returned to the vendors.

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