DGUV Information 203-078 - Thermal hazards from electric fault arc Guide to the ...

Thermal hazards from electric fault arc
Guide to the selection of personal protective equipment for electrical work
(bisher: BGI/GUV-I 5188 E)

Information

DGUV Deutsche Gesetzliche Unfallversicherung Spitzenverband

Published in October 2012

Preliminary remarks

Persons working on or in the vicinity of live electrical equipment are, in principle, exposed to hazards associated with electric fault arc. While an electric arc flash is rare in the normal working environment, its occurrence cannot be ruled out completely. For this reason, persons working in this environment will require reliable protection, especially because incorrectly performed work tasks can cause such arcing. Electric arcs are not only induced by short circuiting, but can also occur between two current-carrying components, when they are separated from each other (e. g. installation/removal of circuit protectors while under load).

The information contained herein is intended to support employers in their selection of suitable equipment (e. g. protective clothing or face shields for electrical work, etc.) for protection against the thermal effects of electric fault arcs. In so doing, a methodology has been adopted based on standardised Box test procedures according to VDE 0682-306-1-2 (see Annex 1).

Depending on the electrical network and equipment configuration, electric arcing can be extremely hazardous:

• High levels of thermal energy.

• Shockwaves and associated fragments released by the explosive propagation of an arc flash.

• High intensity electromagnetic radiation, particularly in the ultraviolet (UV) and infrared (IR) radiation bands, but also in the visible light band, which can lead to irreversible damage to the eyes and skin.

• High levels of acoustic shock (bang).

• Toxic gases and particles produced by melting and vaporised materials in the vicinity of the arc flash (including electrodes).

Each consequence, in itself, can endanger the health and even the life of a person in proximity of the occurrence. The most serious personal risks are associated with the thermal effects of electric fault arcs.

NOTE:
Methodologies based on a selection criteria where PPE is tested according to VDE 0682-306-1-1 (see Annex 1) are already described in NFPA 70e (Standard for Electrical Safety in the Workplace) and IEEE 1584-2002 (Guide for performing arc-flash hazard calculations), among others, and, for this reason, are not presented directly in this guide.

NOTE:
Moreover, an overview of PPE selection is included in the ISSA (International Social Security Association) Guideline for the selection of personal protective equipment when exposed to the thermal effects of an electric fault arc (2nd edition 2011).