ISA TR12.2

Introduction

When electrical equipment is used in locations where fire or explosion hazards may exist due to flammable gases or vapors, flammable liquids, combustible dust, or ignitible fibers or flyings, the National Electrical Code (NEC)®, NFPA 70, requires special precautions to be taken in equipment construction and installation to ensure safe performance. There are several protection techniques in common use, each of which has its own set of advantages and disadvantages.