General Equipment EP8HL, Руководство оператора

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EP8HL HAZARDOUS BLOWER
FORM GOM7069501, VERSION 1.2
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steel carry handle. All wiring devices and components
are designed and certified for use in the applicable
hazardous locations. The electric motor and all related
wiring components of steel construction are positioned
to afford protection against a direct impact blow.
As an illustrative example, consider the potential
consequences if a tool is dropped and strikes a
ventilation blower in use. If the blower is in use within
a nonhazardous atmosphere, the risk for an explosion
is minimal. However, if the same tool strikes the
exposed, steel surfaces of a blower being operated in
a hazardous location that contains gasoline fumes, the
results could be drastically different. The blow
produced by the tool could create a random spark. In
the case of gasoline fumes, the addition of a proper air
and fume mixture could result in an explosion.
Minimizing this potential for a spark ignition is also an
important reason why spark proof tools, statically
conductive shoes/clothing and related equipment are
also utilized in hazardous locations. By incorporating
basic spark proof construction techniques, the
potential for a spark ignited explosion caused by a
direct blow against an exterior surface of the EP8HL
Blower can be greatly minimized. The use of an
explosion proof motor alone or with a housing design
of steel construction does not qualify the blower as
explosion proof. An explosion proof motor only means
that the motor has the structural capacity to survive an
internal explosion. No air ventilation blower is totally
explosion proof. Only a product utilizing proper design
and certification standards can minimize the risk of
providing air ventilation in the applicable hazardous
atmospheres.
STATIC ELECTRICITY CONSIDERATIONS FOR
HAZARDOUS LOCATION TYPE CONFINED SPACE
VENTILATION.
The formation and dissipation of static electricity is a
natural occurrence of any air movement. A common
example is the natural air movement that occurs with
the heating and cooling of the earth's atmosphere. The
resulting winds are responsible for the ionization of
negative and positive charged air molecules.
Eventually, severe charge levels can result in a rapid
discharge in the form of lightning. The phenomenon of
static electric discharge is an important consideration
during the operation of an air ventilation blower in a
hazardous location type atmosphere. A static
discharge can be the ignition source for an explosion.
Only proper product design considerations along with
proper levels of knowledge, skill and common sense
for the air ventilation process can be utilized to
minimize the potential for such an occurrence.
These design considerations collectively employ a
systems approach to problem solving, including the
use of statically conductive air ducts and a properly
grounded, electrical power source.
Air ducts normally used for ventilating a nonhazardous
location type confined space are fabricated from
materials such as a vinyl impregnated polyester. This
material does not conduct a static charge build-up. Air
ducts used for ventilating a hazardous location type
confined space are designed to conduct and dissipate
the electric charges created by the movement of air
through the duct. Without this added conductive
property, air movement creates static electricity
charges on the duct surface that would have no
method for dissipation. Just touching a nonconductive
duct could allow the charge to be dissipated in the
form of a random spark. Such an occurrence could be
the ignition source of an explosion if the Blower is
being operated in the appropriate hazardous location
type atmosphere. Instead, the statically conductive
duct used with the EP8HL Blower allows a static
electrical charge to be effectively conducted through its
length until it is eventually dissipated through the
ground wire of the electric power cord. The EP8HL
Blower is designed so that only the statically
conductive ducts can be utilized with it, thereby
minimizing the potential use of a standard,
nonconductive duct in a hazardous location type
atmosphere.
EXPLOSIVE CHEMICAL PROPERTIES
CONSIDERATIONS FOR HAZARDOUS LOCATION
TYPE CONFINED SPACE VENTILATION.
Certain chemicals may have characteristics that
require safeguards beyond those required for any of
the certified atmospheric groups. Carbon Disulfide is
an example of such a chemical because of its low
ignition temperature and the small joint clearance to
arrest its flame propagation.
Certain metal dusts may have characteristics that
require safeguards beyond those required for
atmospheres containing the dusts of aluminum,
magnesium and their commercial alloys. For example,
zirconium, thorium and uranium dusts have extremely
low ignition temperatures and minimal ignition energies