It is currently quite common for the “arc flash” hazard to be discussed at length among those involved with electrical safety. Often direct contact hazards are not discussed comprehensively because many believe that this hazard has been beaten back. At ESPS Electrical Safety Program Solutions INC. we believe that “all electrical hazards” must be identified, quantified and a comprehensive safe work plan executed. Step one, without question, surrounds the identification of all those electrical hazards.
 

The "Arc Flash Triangle" The "Arc Flash Triangle" is a simple symbol for identifying the electrical hazards of contact (i.e. shock or electrocution), and arc flash. The three elements identified as contributing factors to the incident energy level of the arc flash are the short circuit current (i.e. with the associated arcing fault current), the clearing time for the electrical fault, and the distance the worker is away from the electrical fault.  Influencing any one or several of these factors in a positive manner will reduce the potential arc flash incident energy exposure to the worker (arc gap, electrode material and voltage will also impact the arc flash calculation). The contact hazard is created when there is accidental contact between a human being from the electrical energy source to earth.

Direct contact hazard identification for instance would include a Hazard / Risk evaluation of any possible touch and step potentials. Induced and flashover hazards may be part of the analysis depending on the prescriptive tasks in the individual business unit described.

Once those hazards are identified and quantified if they exist within the prescriptive tasks then a very comprehensive arc flash / blast Hazard / Risk evaluation needs to be carried out.

Some of the hazards that need to be considered here include the radiant and convective heat , IR and UV hazards to the eyes, dB to the ears, pressure wave and concussive forces to external and internal body parts, potential to be thrown into moving parts or other live parts and of course the potential to fall. Each task needs to be comprehensively planned considering all these potential electrical hazards.

The safe work plan is the cornerstone of any task and identification of these hazards as a first step based on leading edge knowledge is key to delivering a safe work place and outstanding business financial performance.