How the NFPA Defines Arc Flash Hazard Risk Categories (HRC)
The NFPA (National Fire Protection Association) provides five Hazard Risk Categories (HRC) to
define the level of an arc flash hazard. Each category is given as a single digit, designed to be easily
read by electrical workers from a safe distance, so that they may assess the relative danger of an arc
flash in a given situation and respond accordingly with the proper precautions and arc flash clothing.
Detailed HRC applications are described within the 2012 NFPA 70E standards, but in general, the
NFPA defines each HRC as follows. HRC 0 is generally used to describe non-contacting work
on various voltage ranges. HRC 1 describes work in an environment that may possibly produce
available incident energy of 4 cal/cm² to 7 cal/cm². HRC 2 describes work in an environment that
may possibly produce available incident energy of 8 cal/cm² to 24 cal/cm². HRC 3 describes work in
an environment that may possibly produce available incident energy of 25 cal/cm² to 39 cal/cm². And
HRC 4 describes work in an environment that may possibly produce available incident energy of 40
cal/cm² and greater.
This entry was posted by Todd Hoffmeister on March 7, 2012 at 7:32 pm, and is filed under PandaPedia. Follow any responses to this post through RSS 2.0.You can leave a response or trackback from your own site.
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Is this right?
HRC 0 is generally used to describe non-contacting work
on various voltage ranges. HRC 1 describes work in an environment that may possibly produce available incident energy of 4 cal/cm² to 7 cal/cm². HRC 2 describes work in an environment that may possibly produce available incident energy of 8 cal/cm² to 24 cal/cm². HRC 3 describes work in
an environment that may possibly produce available incident energy of 25 cal/cm² to 39 cal/cm². And HRC 4 describes work in an environment that may possibly produce available incident energy of 40 cal/cm² and greater.
I thought HRC 0 used to describe non-contacting work on various voltage ranges, HRC 1 – zero risk to 4cal/cm², HRC 2 – to 8cal/cm², HRC 3 – to 25cal/cm² and HRC 4 – 40cal/cm²