Electrical Protective Equipment

Electrical Personal Protective Equipment

Selection

Once the hazard/risk category has been identified, either from NFPA 70E tables or an arc flash analysis, appropriate protective clothing can be selected. Protective clothing includes flame-resistant (FR) shirts, pants, coveralls, jackets, arc flash protective hoods and suits, eyewear, and head protection. The protective clothing selected for the corresponding hazard/risk category number shall have an appropriate arc thermal protective value (ATPV) or rating for the hazard/risk category.

• An Arc Thermal Protective Value (ATPV) refers to the maximum incident energy (in calories per centimeter squared) that protective equipment can be exposed to and prevent the onset of a second-degree burn. Ratings are based upon the total weight of the fabric. Appropriate clothing ranges from untreated cotton, wool, rayon, or silk materials with a fabric weight of at least 4.5 ounces per square yard to flame retardant (treated) clothing worn in layers. For specific guidelines, contact Environmental Health & Safety at 540-231-2341.

Layering

Materials that have an established arc flash rating (ATPV expressed in cal/cm2) are permitted to be used either alone or in combination with materials without an established rating. Layering increases the overall protective characteristics of flame-resistant clothing. 

• Outer layers should be made of flame-resistant material, especially when used in conjunction with ignitable or meltable clothing, such as a rain suit.
  • Flame-resistant rainwear is now available.
  • The outer layers must limit the temperature rise of the ignitable underlayers to no more than 1.2 cal/cm2. 
• Underlayers should be made of non-melting, natural fiber materials, such as untreated cotton, wool, rayon, silk, or blends of these materials. Meltable fibers such as acetate, nylon, polyester, polypropylene, and spandex shall not be permitted in the underwear next to the skin.
  • Incidental amounts of elastic used in non-melting fabric underwear or socks are permitted.

Coverage and Fit

Clothing should cover all potentially exposed areas as completely as possible. Shirt sleeves should be fastened at the wrist and shirts and jackets shall be closed at the neck. Clothing should be loose-fitting to provide additional thermal insulation from the air space between layers and reduce the conduction of heat from the flame-resistant clothing to skin; however, it should fit properly (i.e. not so loose that it interferes with the work task).

Arc Flash Suits

Arc flash suits must be designed to meet all applicable ANSI and ASTM standards and shall have an arc rating. Safety glasses are required to be worn beneath face shields or hoods. Goggles should not be worn because they are permitted by ANSI to have an ignitable and meltable component.

Flame resistant clothing and arc flash suits must be inspected before each use for contamination or damage that could affect the protective qualities of the fabric, such as grease, oil, flammable or combustible liquids spills, or tears. Never use contaminated or damaged protective equipment. Care and maintenance per the manufacturer’s instructions must also be followed in order to maintain the protective properties. A simplified clothing system provides minimum protection for electrical workers in addition to other required personal protective equipment recommended for the specific task.

• Flame-resistant long-sleeve shirt with FR pants or flame-resistant coveralls with a minimum arc rating (ATPV) of 8 cal/cm2 are appropriate for Hazard/Risk Category tasks 1, 2, and 2*.
• A total clothing system consisting of Flame-Resistant shirt and pants and/or flame-resistant coveralls and/or arc flash coat and pants with a minimum arc rating (ATPV) of 40 cal/cm2 is appropriate for Hazard/Risk Category tasks 3 and 4.

Voltage-Rated Gloves

The hands are probably the most exposed part of a worker’s body since they are the closest to the hazard. Voltage-rated gloves with leather protectors are required to be worn as appropriate for the task (see chart). Gloves must be tested by a third party before the first issue and every 6 months thereafter.

• Class 00, 500 vac and 750 vdc maximum use voltage
• Class 0, 1,000 vac and 1,500 vdc maximum use voltage
• Class 1, 7,500 vac and 11,250 vdc maximum use voltage
• Class 2, 17,000 vac and 25,500 vdc maximum use voltage
• Class 3, 26,500 vac and 39,750 vdc maximum use voltage

Foot Protection

Heavy duty leather work shoes provide some arc flash protection to the feet and shall be used in all tasks in hazard/risk category 2 and above.