Arc Flash Safety and Label Information Resource Center
This web site provides employers and safety personnel with a comprehensive introduction to arc flash labels and safety. Our goal is to provide you with an overview of the tools and information you need in order to protect your workers and your business against the threat of arc flash.
Virtually every safety device is intended to minimize one of three contributing factors to incident energy: available current, fault clearing time, or working distance. Several types of devices will be covered on this page, including current limiting fuses, voltage indicators, and infrared scanners.
No safety device can properly protect workers in the absence of a comprehensive safety plan that governs their use. Because safety products are easily visible, many companies make the mistake of thinking that using them is the primary component of arc flash safety. However, having the proper PPE available, for example, is useless unless workers know what to wear and when. Similarly, a warning label means little if employees don't have the training to treat hazards with the care they require. Lewellyn Technology has published an excellent article on Arc Flash Myths and Misconceptions that explores this issue.
Current Limiting Fuses
A current limiting fuse is designed to detect the increased current associated with a short circuit (within their current-limiting range) and clear the fault in 1/2 cycle, limiting the current available for an arc fault. Use of these fuses can greatly decrease the incident energy—and consequently limit the potential for injury—from an arc flash.
Current limiting fuses can certainly reduce risks, but it is a mistake to think that they necessarily do so. If the short-circuit current of a fault is below the current-limiting threshold of a fuse, it may take much longer to clear the fault. Since incident energy depends both on current and on time, use of current limiting fuses may even increase the hazards that workers face, depending on system characteristics. A careful arc flash analysis is necessary to determine the actual risks.
Despite their limitations, current-limiting fuses and breakers are quickly gaining acceptance as a standard safety measure. Companies should seriously consider replacing existing, non-current-limiting devices.
Real-world advice and insight into preventing arc flash accidents.
A voltage indicator is simply a permanent voltmeter attached to equipment. An LED indicates the presence of voltage. By reducing the need for hand-testing of voltage, a voltage indicator reduces the opportunities for an accident and provides warning if equipment has not been de-energized.
The danger of using a voltage indicator is that, while a lit LED proves that voltage is present, a dark LED might indicate either the absence of voltage or a malfunction in the indicator itself. Use of voltage indicators can provide a useful additional safeguard when used with traditional live-dead-live voltmeter techniques, but it should not be used as a replacement.
Infrared thermography of electrical equipment can detect loose connections and other equipment malfunctions that can contribute to arc flash incidents. IR scans are an important part of a complete electrical safety program. However, since many arc flash incidents are caused by dropped tools or other human error, IR scans do not remove the need to perform a complete hazard analysis, or to wear appropriate PPE.
The DuraLabel PRO arc flash labeling package includes a DuraLabel PRO printer, arc flash labeling supplies, and labeling database software that tracks your labels and ensures they include the required information.
Other Safety Devices
Many other safety devices exist that can reduce the risk of arc flash, and new methods are being introduced frequently. A number of remote devices allow workers to rack breakers or operate disconnects without having to approach live equipment. New flash sensors installed inside switchgear detect the light emitted by an arc fault, and trigger protective devices quickly. Links to companies offering a range of protective devices can be found on our arc flash resources page.