Arc Flash Suits1

Components of a typical Arc flash suit: ATPV 12 – 140 CAL

Arc flash suits are designed to provide protection from arc flash heat exposures. Arc flash suits are designed to protect the electrical technician from heat and to reduce or minimize total burn injury. This helps to provide the user with extra seconds of protection to help escape possible secondary explosions or fires in the work area. Arc Flash suits can increase the chances of survival. Arc Flash suits will decrease the need for medical treatment such as skin grafts and the reduction in chances of subsequent infections.

Safety is always a first priority in electrical engineering. The preservation of life is imperative. Arc Flash suits are a small cost in comparison to the loss in quality of life if a worker is exposed to an electric arc event. Electrical technicians, by law should always wear and be properly trained in the safe use and application of Arc Flash suits and appropriate personal protective equipment such as insulated rescue sticks for the possible electrical hazard with which they may face. Arc Flash clothing have long life spans if proper cleaning and maintenance of is implemented.

Arc flash is a short circuit through air that flashes over from one exposed live conductor to another conductor or to ground.

Arc flashes occur in many ways:

1. Coming close to a high-amp source with a conductive object can cause the electricity to flash over.
2. Dropping a tool or otherwise creating a spark can ignite an arc flash
3. Equipment failure due to use of substandard parts, improper installation, or even normal wear and tear
4. Breaks or gaps in insulation
5. Dust, corrosion or other impurities on the surface of the conductor

The NFPA 70E instructs employers to conduct an arc flash analysis to determine the amount of thermal energy that could be generated in an arc flash incident. The information is then used to define a flash protection boundary around the potential source, and to determine the level of arc-rated apparel and other personal protection equipment required when employees cross the boundary while they work on or near exposed live parts.

Function of Du Pont Nomex LLT Arc Save flash ® suits :

The protection provided from Nomex Arc Flash suites gives a person the benefit of a few seconds to escape the Arc flash, by preventing the burning of skin. The main characteristic of Nomex material is to self extinguish. ( FR – Inherently flame retardant – not treated).

DuPont™ Nomex® fibre is inherently flame-resistant, will not melt or drip, and does not support combustion in the air, thus providing excellent arc flash protection. And because the protection is woven right into Nomex® garments, it cannot wear off of wash out over time.

When exposed to the intense heat typical of electric arc, Nomex® fibre carbonises and thickens. This increases the protective barrier between the heat source and the wearer’s skin and helps minimise burn injury.

Nomex Arc flash suites should always be worn when operating high voltage systems for example 11kv, 22kv or 33kv systems in applications such as switchgear inside Substations. (eg. 132kv/11kv) This is to protect against the potential hazard of an arc flash.

The correct arc flash risk assessment needs to be carried out before an ATPV – Arc Thermal Performance value can be determined. The greater the ATPV value.

Sizes:
Small – 5XL (prices do vary according to size).

Colour Range:
Olive, Black, Navy blue, Orange

International Standards :

Fabric: ASTM F1506; NFPA 70E; OSHA 1910.269; ; ASTM F1959 : SANS 724; ASTM F2621; ;
ATPV¹ : from 12 cal/cm², 55 cal/cm² to 140 cal/cm²
HAF² : 93.9%

Features:

• Light Weight
• Material: Multi-layer DuPont™ Nomex® / DuPont™ Kevlar® / Modacrylic
• Guaranteed flame resistant for the life of the garment.
• Machine washable.
• Excellent breathability.
• Cool cotton comfort.
• Arc Flash Jacket designed to interface with Arc Flash Hood.

LLT Save Arc Ratings :

An electrical arc flash is more severe with higher voltages & higher fault level ratings of the equipment (switchgear) substation. The greater the flash, the greater the severity of the radiation exposed to the operator. It is imperative to get the correct grading of the Nomex Flash suite to ensure the necessary protection against radiation of the Arc flash.

LLT Save Arc Thermal Performance values (ATPV) ;

Arc Thermal Performance value (ATPV value) is presented in calories per centimeter square and represents the maximum capability possible from an arc flash protection for particular clothing.

Characteristics of ARC fabric :

• The fiber itself absorbs heat energy during the carbonization process.
• The fibers eliminate air movement and heat transfer to the interior skin area.
• An insulating barrier reduces heat transfer to the person.

ARC Flash clothing categories: NFPA 70 E standard code

There are 4 categories into which ARC Flash clothing are divided into: