2 What is an fault arc - Die BG ETEM

5 Standardized test procedures for PPE products against thermal arc hazards
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IEC 61482-1-1 IEC 61482-1-2
Set-up Long open arc Arc in a box
Test energy Variable adjusted by arc constant, two possible
duration at constant test levels (classes)
current
Heat transfer All directions: Focussed:
mainly radiation Radiation, convection,
metal splash
Test result Arc rating (ATPV or EBT50) Arc flash protection class: y/n
Tab. 5.1: Specifics of the two standardized test procedures optionally to be used
Important is that the test results are energy levels up to which the PPE shows arc
resistance and protection. In the past, both manufacturers and users compared
tested material or clothing and considered the application very often only on the
basis of the prospective test current value (8 kA in case of ATPV testing, 4 or 7 kA
respectively in box testing) without taking into consideration the other important
set-up parameters determining energy levels (that means: exposure levels and, thus
protection levels).
The test procedures of IEC 61482-1-1 (methods A and B) [3] determine a quantitative
value characterizing the thermal protective performance of the material or clothing:
the Arc Thermal Performance Value (ATPV) or the Break Open Energy (EBT50)
respectively. The value (material property) makes it possible to compare different
materials to each other. It is also possible to compare this value to the predicted
incident energy of an electric arc accident in any particular working environment,
based on the information gained by means of according procedures of the risk
assessment of that environment (e.g. IEEE 1585 or NFPA 70E, see chapter 8).
Material or clothing tested by the box test method with constant test parameters
show protection at minimum up to the class energy level, the actual protection level
may be higher. The test parameters are in general not the PPE application limits.
Protection is almost given up to system currents and voltages, arc durations and
exposure distances as long as the class energy level is not exceeded. The necessary
arc flash class has to be selected on the base of a risk analysis. Other methods as
mentioned above must be used because the according arc energy levels have to be
found (see chapter 8).