RISK ASSESSMENT - HAZARD OF ELECTRIC ARC FLASH

In addition to the European standard EN 61482-2, there are several international guidelines and recommendations that provide guidance on the practical assessment and management of risks associated with electrical hazards. Examples of such documents include NFPA 70E, ISSA Guidelines and DGUV-I 203-077. These complement the standard by describing methods for risk assessment, safe working procedures and the selection of appropriate personal protective equipment.

NFPA 70E - American standard for electrical safety in the workplace

The American standard for electrical safety in the workplace, NFPA 70E, is a consensus standard that explains how to protect the user against, among other hazards, the risks associated with arc flash hazards. The standard is designed to help employers and staff understand electrical hazards and provides guidance on risk assessment, the selection of appropriate PPE where there is a risk of arc flash, and safe working practices.

When choosing protective clothing and other PPE to protect against arc flash hazards, NFPA 70E specifies two methods:

Calculated incident energy
The category method

The choice of method depends on whether the incident energy to which the worker may be exposed has been calculated or not.

Calculated incident energy - NFPA 70E:2018 130.5 according to IEEE1584:2018

The level of the protection must be greater than the magnitude of the hazard, which means that the certified protection level must be greater than the calculated incident energy. The lists below show which protective clothing must be worn at different calculated energy levels:

Risk of arc flash at 1.2–12 cal/cm²

Arc flash tested jacket/trousers/coverall with long sleeves/legs
Arc flash tested helmet/visor with balaclava or arc flash hood with integrated visor
Arc flash tested gloves, heavy leather gloves or insulating gloves with leather covers
Safety glasses under visor
Hearing protection
Fully covering leather shoes

Risk of arc flash at > 12 cal/cm²

Arc flash tested jacket/trousers/coverall with long sleeves/legs
Arc flash hood with integrated visor shall protect the face (arc flash tested helmet/visor with balaclava is not approved)
The gloves shall be certified for arc flash (heavy leather gloves or insulating gloves with leather covers are not approved)
Safety glasses under visor
Hearing protection
Fully covering leather shoes

The category method - NFPA 70E:2018 130.7

The category method is only used when the incident energy has not been calculated. Using the category method, you compare your installation with typical installations listed in NFPA 70E 130.7, which provide guidance on the appropriate PPE category to select. This method may be more conservative and may result in the wearer using thicker and heavier protective clothing than necessary for the work being carried out.

Arc flash protection for the protective clothing is divided into four PPE categories:
Assessed risk according to the category method (cal/cm²)	1.2–4	4–8	8–25	25–40
Arc Rating requirements for the protective clothing (cal/cm²)	> 4	> 8	> 25	> 40
Required PPE category	PPE 1 / CAT 1 (4–8 cal/cm²)	PPE 2 / CAT 2 (8–25 cal/cm²)	PPE 3 / CAT 3 (25–40 cal/cm²)	PPE 4 / CAT 4 (>40 cal/cm²)

The lists below show which protective clothing shall be worn:

For arc flash risk that requires the use of PPE 1 or 2:

Arc flash tested jacket/trousers/coverall with long sleeves/legs
Arc flash tested helmet/visor with balaclava or arc flash hood with integrated visor
Arc flash tested gloves, heavy leather gloves or insulating gloves with leather covers
Safety glasses under visor
Hearing protection
Fully covering leather shoes

For arc flash risk that requires the use of PPE 3 or 4:

Arc flash tested jacket/trousers/coverall with long sleeves/legs
Arc flash hood with integrated visor shall protect the face (arc flash tested helmet/visor with balaclava is not approved)
The gloves shall be certified for arc flash (heavy leather gloves or insulating gloves with leather covers are not approved)
Safety glasses under visor
Hearing protection
Fully covering leather shoes

Certificate of conformity - NFPA 70E / EN 61482-2

Tranemo, in cooperation with ArcWear, an accredited test institute in the USA, has produced a certificate showing that our EN 61482-2 certified protective clothing also meets the requirements of the American standard NFPA 70E. The certificate confirms that Tranemo’s CE-marked arc-rated protective clothing may also be used on the American market.

ASTM F1959

ASTM F1506 is the American standard for arc flash risks. In the standard, the fabrics are tested with the Open Arc test ASTM F1959, which is similar to the European test method EN IEC 61482-1-1 for fabrics and garments. The biggest difference between the American and European standards is the requirement for testing the char length where a maximum value is specified. The test is carried out after 25 washes and to pass the test the char length may be a maximum of 152 mm following 12 seconds of exposure. Tranemo has tested the fabrics Tera TX and Aramid 6.4FC which have been developed for electricians. The result provides a useful indication of the fabric’s flame protection properties in the event of an arc flash.

Protective clothing designed to provide designed to provide electrical insulation against electric shock, or clothing intended for work where an electric arc is intentionally generated, e.g. arc welding and plasma cutting, is not covered by the EN 61482-2 standard.

DGUV-I 203-077 - German GUIDELINE for electrical safety in the workplace

DGUV-I 203-077 is a German guideline that describes safe working methods when working on or in the vicinity of electrical installations. The document provides practical guidance on risk assessment, work procedures, competence requirements and the selection of personal protective equipment to reduce the risk of electric shock and arc flash accidents. The guideline is used mainly in Germany and complements national regulations as well as European standards.

The German standard is based on risk assessment according to DGUV-I 203-077 and risk calculations according to BGI/GUV-I 5188. Protective clothing is tested according to EN 61482-1-2 Box Test, which creates a limited and directed arc that is created by a short circuit in an open cabinet. The test is carried out in a low-voltage area (400V).