IEC 61482-2 standard: protective clothing against the thermal hazards of an electric arc

In a work environment where thermal hazards due to exposure to the energy of an electric arc are possible, it is therefore necessary to have adequate clothing. The following standard: IEC 61482-2 defines protective clothing for carrying out work under voltage during which exposure to an electric arc constitutes a risk for the workers. These PPE thus protect against the thermal consequences of an electric arc. Also called Arc Flash, the latter refers to a discharge that passes through the air of high or low voltage electricity between conductive elements. The risk associated with the use of this tool occurs during maintenance work or electrical installations. Thermal hazards can have the main human risk for the user, therefore, being serious burns, even fatal, damage to the respiratory tract, hearing loss, etc. Wearing appropriate protection over the whole body will be required to guard against these risks of permanent injury and ensure a safe working environment.

The usefulness of IEC 61482-2 certified PPE

Protective clothing that complies with the IEC 61482-2 standard falls into risk class III. They are identifiable by the normative pictogram visible on the work clothes. The symbol determines the electric arc protection class of equipment and clothing by means of a limited and targeted electric arc. There are two ways to assess the resistance of work clothes to thermal hazards.

Box test

In Europe, the “box test” is used to test the effectiveness of this protection. This test method is comparable to CLC TS 50354. The test in question consists of a test chamber causing a short circuit, thus causing a huge jet of flame to shoot out. The temperature will be measured on the outer side of the fabric and the electric arc does not last longer than 500 ms. This helps determine if the heat is being removed quickly enough or if the heat is too intense. After exposure, the garment must remain functional. In other words, the seams remain intact and the accessories (zippers) still operational. If the results are positive, the garment can be marked in class 1. With an electrical power of 4 kA or 7 kA, the garment will be classified in class 2. Referring to these data, the time required to generate a second degree burn. The test will also assess kindling, hole formation and melting.

Open Arc test

The second test method is called the “Open Arc Test” where the resistance of the arc will be expressed in ATPV (Arc Thermal Performance Value). This value designates the maximum incident thermal energy where a material protects the wearer against second degree burns. This test has the advantage of being able to choose a PPE in a more targeted way according to this ATPV value. In addition, the Open Arc Test is considered to be more effective in selecting the appropriate personal protective equipment in a work environment exposed to this type of risk.

The requirements set out in standard 61482-2/ IEC are applied to welding clothing EN ISO11611. Protective clothing alone is not sufficient protection and must be combined with other protective equipment such as helmets, gloves and visor, safety footwear.