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General Technical Information for Electrical Equipment in 12
Hazardous Environments
697
Harzardous Environments vapors or mixtures with air under DIN EN 1127-1 and all other related
Hazardous environments are areas in atmospheric conditions in critically standards that are commonly known
which the atmosphere may become mixed ratios such that excessive high divide up hazardous areas according
explosive. Explosive atmosphere is temperature, arcs or sparks may cause to the likelihood of the occurrence of an
defined as a mixture of ignitable an explosion. explosive atmosphere into the following
substances in the form of gases, zones:
1 Hazardous environments as a result
1
of combustible gases, vapors or mist.
Zone 0:
Area in which an explosive gas/air mix-
ture is continuously present or
present for long periods.
Zone 1:
Zone 2
Area in which an explosive
atmosphere can occur during normal
operation.
Zone 0
Zone 2:
Zone 1
Area in which an explosive
Zone 1
atmosphere is unlikely to occur under
normal operation and if it does it will
be for a short period.
Zone 0 Zone 0
2 Hazardous areas caused by
combustible dust
2 Zone 20:
Area in which an explosive dusty
atmosphere is present "permanently",
for "long periods" or "frequently" and
Zone 22
in which deposits of combustible dust
of unknown or excessive thickness may
be formed. Dust deposits alone are not
grounds for classification as Zone 20.
Zone 21:
Area in which an explosive dusty
atmosphere is present "occasionally"
under normal operating conditions and
in which deposits or layers of
Zone 21 combustible dust can generally be
present.
Zone 20
Zone 22:
Area in which an explosive dusty
atmosphere is not likely to occur during
only exist for a "short period", or in which 12
normal operation and, if it occurs, will
accumulations or layers of combustible
dust are present.
Please refer to the manuals for more information on explosion protection.
