Arc Flash

Provided by Jarvis Franck

Arc flash is the energy release that occurs during an electrical fault when current flows through the air between two live conductors, causing a short circuit. Arc flashes can happen at varying voltage amounts, but severity greatly increases in a commercial setting where currents and voltages are significantly higher.

Arc Flash vs Arc Blast

Even though both are the result of an abrupt electrical discharge, there are some differences worth noting.

“Arc Flash” refers to the energy released from an electrical arc. The energy lets off intense heat and light, which can cause burns. Arc flashes also release air and gas into the atmosphere – this phenomenon is known as an “Arc Blast.”

“Arc Blast” is the pressure wave created by an arc flash, pressure that can cause all sorts of damage to structures, equipment, or nearby workers. Both arc flash and arc blast create serious hazards to workers, particularly those who work in close proximity to electrical systems.

Main Causes

Poor Maintenance: Arc flashes can be the result of poor electrical maintenance. Issues can come from degrading electrical systems that may have compromised components or worn insulation. Loose connections can also cause arcing or overheating of electrical components which increase the probability of Arc Flashes.

Environment: Moisture, dust, condensation, or other flammable debris.

Human Error: Improper installation of components, accidental contact with energized components, or improper lock out tag out procedures.

Prevention

Education: All employees need to be fully aware of the risks associated with electrical systems, no matter what the voltage is. Accidental contact with 220/480 systems is most times deadly or results in severe injury. All high voltage work must be preformed by trained professionals.

Labeling: All panels need to be properly labeled with critical information of the electrical component’s characteristics. These labels, as well as safe distance markers are crucial to keeping employees safe.

PPE:  Personal Protective Equipment is critical in protecting workers from Arc Flashes. Proper PPE consists of garments specifically for Arc Flashes that are made from flame-resistant materials to prevent or reduce the severity of burn injuries. Hard hats may also be worn to help protect against Arc Flash collateral damage, such as fling debris, or any other physical hazards created by an Arc Flash.