This document is intended to provide guidance for the calculation of incident energy and arc-flash protection boundaries. Once calculated, this information can be used as a basis to develop strategies that have the goal of minimizing burn injuries. Strategies include specifying the rating of personal protective equipment (PPE), working deenergized, applying arc-resistant switchgear, and following other engineering techniques and work practices.
This guide is based upon testing and analysis of the hazard presented by incident energy. The potentially hazardous effects of molten metal splatter, projectiles, pressure impulses, and toxic arc by-products have not been considered in these methods. It is expected that future work will provide guidance for these other electrical hazards.
Available bolted fault currents should be determined at the point of each potential fault. Do not use overly conservative bolted fault current values. A conservatively high value may result in lower calculated incident energy than may actually be possible depending on the protective device’s time-current response. The lower results would be caused by using a faster time-current response value from the protective device’s time-current curve.
Where used, PPE for the arc-flash hazard is the last line of defense. The protection is not intended to prevent all injuries but to mitigate the impact of an arc flash upon the individual, should one occur. In many cases, the use of PPE has saved lives or prevented injury. The calculations in this guide will lead to selection of a level of PPE that is a balance between the calculated estimated incident energy exposure and the work activity being performed while meeting the following concerns:
The desire to provide enough protection to prevent a second degree burn in all cases.
The desire to avoid providing more protection than is needed. Hazards may be introduced by the garments such as heat stress, poor visibility, and limited body movement.
Professional judgement must be used in the selection of adequate PPE.
While it is outside the scope of this document to mandate PPE, some examples of where PPE may be required are: during load interruption, during the visual inspection that verifies that all disconnecting devices are open, and during the lockout/tagout. Adequate PPE is required during the tests to verify the absence of voltage after the circuits are deenergized and properly locked out/tagged out.
This information is based on technical data believed by the IEEE Std 1584-2002 working group to be reliable. It is offered as a tool for conducting an arc-flash hazard analysis. It is intended for use only by those experienced in power system studies and is not intended to substitute for the users’ judgment or review in such studies. It is subject to revision as additional knowledge and experience is gained. IEEE, those companies that contributed test data, and those people who worked on development of this standard make no guarantee of results and assume no obligation or liability whatsoever in connection with this information.
This guide is not intended to imply that workers be allowed to perform work on exposed energized equipment or circuit parts. It must be emphasized that the industry-recommended way to minimize electrical injuries and fatalities is to ensure that equipment is deenergized and in an electrically safe work condition. But even this act, creating an electrically safe work condition, subjects the worker to potential hazards, which if they occur, require PPE for protection against arc-flash burns.
Topic: IEEE Std 1584-2002 Arc-Flash Hazard Calculator (Read 22 times)
