What are the limitations of an arc flash rated suit?
A common misperception is that a person wearing an arc rated suit is “bullet proof” from the hazards associated with electricity. There are 3 main potential hazards when working with electricity: Electric Shock, Arc Flash and Arc Blast. An arc flash suit can protect you from an arc flash provided that the incident energy level that the suit is exposed to is equal to or less than what the suit is rated for. All arc tested suits will come labeled with an estimated APTV level measured in calories/cm2. Oberon recommends having a risk assessment done before working on any electrical equipment to help identify the possible risks associated with the work task to be performed. Once this analysis is done the appropriate APTV level needed can be determined and the proper PPE selected.
This leaves two other potential electrical hazards that could potentially harm you. The arc blast is high pressure sound wave that is caused by a sudden arc fault. It can cause molten metal droplets to be propelled at high speeds as well as sudden expansion of air pressure that can blast out. An arc flash suit offers some protection from these types hazards, but only in a limited capacity. For instance, if a blast pressure wave were to be strong enough to propel a worker across a room an arc flash suit would not be able to protect the worker from the force of the wave.
The last type of electrical hazard that a worker can be exposed to is electrical shock. Shocks are caused when contact is made by a worker with an electrical energy source. Arc flash suits are not tested or designed to protect workers from this type of hazard. Typically workers will wear rubber electrical gloves with leather protectors when there is a risk of electrical shock while performing their work task.