The IEC 61482-2 standard specifies requirements and test methods applicable to materials and garments for protection against the thermal hazards of an electric arc. An electric arc is a continuous high-voltage electric discharge between conductors generating light and very intense heat.
In jobs such as electric arc welding, the operator can be exposed to flames, radiation and metal splashes from electrodes. The clothing must therefore offer protection by means of adequate insulation against incandescent agents.
The work clothing must fully cover the body to guarantee an ideal protection level. Jackets and trousers must be used together with other protective devices, including helmet with visor, protective gloves and safety footwear. The protection level for the operator increases according to the stratification of the garments worn.
In fact, it is recommended to wear fireproof intimate apparel underneath the fireproof clothing.
There are two international test methods for the specification of information on the resistance of clothing to the thermal effects of electric arcs. Each method supplies different information. The methods are explained in the following standards:
Container test method CEI EN 61482-1-2:
The fabric/garment is exposed to an electric arc constrained in a specific container with a specific electrode arrangement for 0.5 seconds.
Class 1) corresponds to an arc current of 4kA;
Class 2) corresponds to an arc current of 7 kA.
The test conditions for class 1 and 2 try to stimulate the typical exposure conditions for short-circuit current of 4kA and 7kA respectively
Open arc method CEI EN 61482-1-1:
This test message aims at establishing the ATPV (Arc Thermal Performance Value) or (Energy Breakopen Threshold) of a fabric. The ATPV is the amount of energy required to cause a second-degree burn. The Ebt is the amount of energy that opens the material. Both are expressed in calories per cm2. The HAF (Heat Attenuation Factor) is also measured during the test, describing the amount of heat blocked by the fabric.