OPW M2010-EU, Руководство по установке

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1.4 Hazardous Areas
N F PA/N EC – C l a s s I, D i v . 1 & D i v . 2
Class I locations
. Class I locations: Where flammable gases or vapors are or can be in the air in quantities
sufficient to cause explosive or ignitable mixtures. Class I locations include:
l
Class I, Division 1 . A Class I, Division 1 location is a location where:
n
There can be concentrations of flammable vapors during normal operation.
n
There can be concentrations of flammable vapors during repair or maintenance operations or
when the leakage of liquid fuel can occur.
n
A release of concentrations of flammable vapors can occur as a result of equipment failure,
incorrect operation or unsatisfactory procedures that could also cause a failure of electrical
equipment.
l
Class I, Division 2 . A Class I, Division 2 location is a location where:
n
An accidental failure or incorrect operation of vapor containment system equipment or
containers that can release hazardous vapors from flammable liquids or gases.
n
A failure or incorrect operation of positive mechanical ventilation precautions result in the
release of hazardous concentrations of flammable gases or vapors.
n
Concentrations of flammable gases or vapors can occasionally flow from a containment or
ventilation system to an adjacent Class I, Division 1 location. This flow of gases or vapors must
be prevented by sufficient positive-pressure ventilation from a source of clean air. Sufficient
precautions to prevent ventilation failure must be installed.
Doc. No.: M2010-EU Rev.: 13
Page 11 of 149