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- What is an Arc Flash
?
- Why do I need to do an
Arc Flash Analysis ?
- What Electrical Panels
need to be done ?
- What kind of standards
must I follow
?
- Do I need a One Line
Drawing and a Coordination Study ?
- Why can't I just use
default tables to get the information
?
What is an Arc Flash
?
An Arc Flash occurs when a fault condition or
short circuit occurs due to either a phase to ground or phase to
phase conductor being connected. This connection can occur by
accidentally dropping tools, accidental contact with the electrical
system, improper work techniques, dust, or corrosion build up or
several other possible conditions. Even shorting across two
conductors accidentally with a meter lead can cause this condition.
When this happen an Arc Flash occurs. This leads to an explosive
release of energy, known as an arc blast or flash.
Why do I need to do an Arc
Flash Analysis ?
The National Fire Protection Association's 70E
publication 2000, Part II 2-1.3.3 regarding Arc Flash Analysis
states that a "Flash Hazard Analysis shall be done before a person
approaches any exposed electrical conductor or circuit part that has
not been placed in an electrical safe work condition". This Arc
Flash Hazard Analysis must be done to determine the level of
Personal Protection Equipment PPE that a worker must use, and the
Arc Flash Boundary in inches along with the incident energy found at
each location. Each panel must be marked with an ANSI z535 approved
Arc Flash Warning Label.
What Electrical Panels need
to be done ?
The National Electrical Code, NFPA 70E and
OSHA list that all panel boards, switch panels, fuse panels, breaker
panels, motor control centers, motor control panels be surveyed and
labeled with the ANSI approved label. IN ADDITION... the list is
concluded by stating "Any panel likely to be serviced by a worker"
SO, that means any electrical enclosure such as disconnects and
machinery attached to the "hard wired" electrical system in your
facility.
What kind of standards must
I follow
?
This Arc Flash Analysis must be performed to
determine the available arc fault currents and arc flash hazards.
The most effective ways are based on the NFPA 70E or IEEE 1584
methods. Both of these methods are acceptable methods to use and are
allowed by OSHA to comply with these arc flash regulations. OSHA
recommends that the Arc Flash Analysis be done by an independent
consulting firm to reduce any bias that may occur when done
in-house.
Do I need a One Line
Drawing and a Coordination Study ?
OSHA requires that "If You Have" an One Line
diagram of your electrical system, that it be kept up to date.
Meaning that every change must be recorder in that drawing. HOWEVER,
you are not required to have a one line diagram of your facilities
electrical system. Given, This is a very useful tool to have when
servicing your electrical system, and ITU can render that drawing
for you. THIS IS IMPORTANT WHEN CHOOSING A CONSULTANT... Most
engineering companies use a "Canned" software program that requires
them to construct a one line drawing while conducting your Arc Flash
Analysis. They want YOU to pay for that service! While
we ITU Engineers use the ETAP Advanced Electrical Modeling
Software that is widely accepted and the only software allowed to be
used in some military and corporate situation, this software is used
to build a ANSI based single line drawing, we
do not require that you pay additional fees for your
One Line Diagrams .
This lowers the cost to you significantly!
Why can't I just use
default tables to get the information
?
The regulations clearly state that an Arc Flash
Analysis must be performed to determine these values. By performing
a proper arc flash analysis by calculation, you insure that your
workers are using the proper personal protection equipment ( PPE )
and other proper safety equipment is being used.
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