05.30.08
Arc Flash
One of the most potentially damaging and dangerous types of workplace injury is arc flash. Associated with repairs or maintenance of live electrical equipment, arc flash is a breakdown in the resistance of the air that occurs where there is high enough voltage present and a path to ground or a lower voltage. In its most extreme form it can result in a fireball of super heated plasma gas that can reach upwards of 30,000 degrees F, ejecting light and heat energy as well as fragments of equipment and tools towards the technician.
All safety authorities have awareness programs for arc flash, and they usually begin by stating that the number one way to prevent this hazard is to de-energize the circuit. However, they also recognize that this is not always possible. In such cases, mitigation of risk is the next step that must be taken. How is arc flash risk mitigated? There are several components:
-employees must be properly trained in the dangers of arc flash
-preventative maintenance and regular testing of all electrical equipment
-usage of current limiting fuses and other upstream safety devices
-incorporation of arc flash into the facility’s regular safety and accident prevention program
-equipment at risk must be inventoried and assessed, including voltage potential and approach boundaries
-provision and mandated use of personal protective equipment (face, hand, and body protection) on all live electrical circuits
In the US OSHA does not have a specific standard regarding arc flash, but they consider NFPA (National Fire Protection Association) 70E a recognized industry standard practice. In Canada CSA (Canadian Standards Association) is working on a 2008 release of Arc Flash Standard CSA Z462. The ESA (Electrical Safety Authority) has recognized the need for education on the dangers of arc flash, and their website contains valuable information on this subject. They too recommend not working on live circuits, but in the event that this is not possible, they state the following:
“If it is not practical to disconnect an electrical system workers should follow the rules outlined to protect them, which include the use of: personal protective equipment, approved rubber gloves, mats and shields, and insulated tools.”
- from the Electrical Safety Authority brochure, Don’t Work Live.
Wiha Quality Tools has recognized this trend and has been busy expanding their range of insulated tools. All are rated at 1000 Volts AC but are tested to 10,000 volts, a safety factor of ten. WorldTools.com is proud to offer Wiha insulated tools.Wiha Insulated Arc Flash Electrical Tools