19.10.2009

DuPont

HIGH ENERGY ARC KIT ATPV 40 cal/cm2: Electric Arc Protection from Head to Toe

PWG has launched a HIGH ENERGY ARC KIT made from Nomex® that introduces the latest technology in protective clothing against electric arc. The kit, with Arc Thermal Performance Value (ATPV) >40 cal/cm2 and certified to IEC 61482-1-1 and IEC 61482-1-2 class 2, consists of a jacket, trousers, hood and gloves that can be used in conjunction with respiratory equipment.

Safety engineers from DuPont production plants recognised the need for a high energy arc kit because of the risks faced by them whilst carrying out operations such as changing switches in electrical distribution systems or maintenance routines in low voltage environments. These could be prone to electrical arc hazards resulting in incident energies of up to 40 cal/cm² and an individual who is not sufficiently protected may receive life threatening burns. As a result DuPont safety managers called for full body personal protective clothing including high performance protection for the head and hands. PWG designed the HIGH ENERGY ARC KIT that features jacket, trousers, a hood and gloves. The kit has been successfully tested and certified as electric arc protective clothing with ATPV > 40 cal/cm2.

ATPV: indication of protection against electric arc
The ATPV indicates the maximum thermal energy – usually in cal/cm2 – to which a fabric (protective material) can be exposed without the wearer suffering second degree burns. Unprotected human skin may show such an injury when exposed to about 1.2 cal/cm2 energy; the same amount of energy created by the flame of a cigarette lighter pointed at the skin for one second. The higher the ATPV rating, the higher the protective properties of the garment.

Three layers of Nomex®
The material for the HIGH ENERGY ARC suit was selected to achieve both high protective performance and maximum comfort. A combination of two layers of Nomex® Comfort was selected plus one layer of Nomex® felt. The Nomex® Comfort fabric includes Kevlar® fibres for improved tear resistance and P140 fibres for permanent antistatic properties. The three layer construction combines high inherent flame and heat resistance with durability and electric arc protection against incident energies up to 40 cal/cm².
Fabrics made from Nomex® do not burn or melt and, even at relatively low weights per square meter, can withstand the extreme impact of an electric arc.

Lighter weight, comfortable clothing
In conjunction with the weaver Estambril, a NOMEX® quality partner, DuPont evaluated several fabrics and compositions. Finally two layers of Nomex® Comfort plus one layer of Nomex® felt performed the best. Tjeerd Sorgedrager, sales director at PWG said: “This special combination enables us to offer an ultimate protection level combined with a degree of freedom of movement that can be worn like a regular working outfit”. The weight of the jacket and trousers is just 2.5 kg resulting in a light weight solution with a high level of arc protection.

Innovative design for enhanced freedom of movement
Despite its high protective performance, the HIGH ENERGY Arc suit features a dynamic design with additional solutions for greater comfort and wear. Whilst being an industrial protective suit, the sporty style of the jacket resembles modern high-tech fire fighter clothing. The fit of the jacket allows freedom of movement and can be adapted perfectly to the body with Velcro fastenings in the lower end of the back. Incorporating a flame resistant zip in the jacket means there is no need to have a big zip cover, and the zip can be opened and closed even whilst wearing gloves. Wearer trials confirmed the high levels of comfort and movement and the wide vision visor was specially acknowledged because of its particular design.

Exposed parts protected by an additional layer of Nomex® Comfort
The trousers are designed in a similar way to the jacket. They include numerous Velcro fastenings for individual hip adjustments or to widen the trouser legs around the shin, so that they can be slipped on over shoes. All Velcro fasteners are provided with a Nomex® Comfort fabric cover to protect these areas against heat. The shoulder and shin areas also feature an additional layer of Nomex® Comfort for extra protection in these exposed areas.

Head protection with clear vision and an integrated respirator
In addition to the jacket and trousers the PWG HIGH ENERGY ARC KIT offers safety gloves and a protective hood made from Nomex® Comfort. The hood incorporates a convex visor providing a wide field of vision. The double glazed visor is made of polycarbonate featuring a system where the external protective visor can be exchanged. Thus the inner lying green visor that protects against the light flash is protected permanently against scratches. Integrated in the hood is a safety helmet as well as an adaptor for a ventilation tube for optional use of a respirator to supply the wearer with fresh air and prevent the visor from fogging.

Extensively checked safety
The protective suit with hood and gloves is certified to EN ISO 11612 for flame and heat resistance as well as EN 1149-5 for anti-static. The safety gloves are tested to EN 407 for thermal protective effect. The high performance of the HIGH ENERGY ARC KIT was further tested according to IEC 61482-1-1 with an ATPV of 44 cal/cm ². An additional test according to IEC 61482-1-2 box test class-2 standard with 7 kA/ 0.5 seconds was successfully passed. Tests on DuPont™ Thermo-Man® showed a result of 0% body burn (including the head) after 4 seconds of exposure.