Secra E40 – best arch flash protection in the world!

According to the NFPA 70E [1] standard, arc flash incidents occur five to ten times a day (in the USA and Canada). The occurrence of an arc flash is the most severe threat in the power system.  
The destructive outcome of an arc flash can lead to serious injury to operating staff, costly damage to electrical equipment and prolonged system downtime. 

The event energy analysis method is defined by NFPA 70E and IEEE 1584 [2].  

The two main parameters are: 

1. Arc discharge energy (incident energy) – the amount of thermal energy at a specified distance from the arc source, represented in units of calories per square centimetre(cal/cm2). 

2. Arc flash Boundary – the distance at which the incident energy is 1.2 cal/cm2.  
At the value of 1.2 cal/cm2, without PPE, an operator can suffer second-degree burns. 

The arc discharge energy and arc flash boundary for each circuit are determined using the equations in the IEEE 1584 standard. 

Protective clothing in the form of overalls made of flame retardant materials, leather and electrical insulating gloves protects the electricians against the thermal effects of an arc flash. However,  
the most crucial issue is the face protection of the electrician. The principal intent of headgear with  
a visor is to protect the face and more sensitive parts such as the eyes and respiratory tract. The face shield production is even more difficult due to the required transparent material and design allowing the user to breathe. 

Helmet wearers use various criteria in electing and determining the performance of their helmets.  
It depends on the standards and legal regulations in force in the respective country. For example, European Union countries use EN standards [3-7] and Regulation 2016/425 of the European Parliament on personal protective equipment [8]. Countries in the Americas and Australia use the American standards ANSI [9, 10] and ASTM [11] or the Canadian CSA [12-13] and the NPFA 70E standard for safe work practices intended to protect workers by reducing exposure to electrical hazards and assisting in meeting the requirements of OSHA 1910. (Occupational Safety and Health Administration  
– is a government institution that ensures compliance with regulations that protect the safety and health of employees in the US), while GOST standards are in force in Russia and the former countries of the Commonwealth of Independent States [14]. 

It is necessary to meet the standards and legal requirements of the country to introduce a new helmet to the market. It is important to note that users commonly require helmets to meet the standards in force in their country and the exact or exceeding parameters established in the criteria of other countries.  

For example: 

  1. The 1st standard EN50365 [5] requires conducting electrical tests with a test voltage of 5 kV and 10 kV and specifies the maximum operating voltage at the level of 1,000 V AC and 1,500 V DC. On the other hand, the ANSI Z89.1 [9] standard for conducting electrical tests requires a test voltage of 20 kV and 30 kV and specifies a maximum operating voltage at the level of 17 500 V. Due to the relatively low electrical requirements of the European standard, many customers in Europe require helmets with electrical insulation that allow usage in works near medium voltage (up to 15 kV).  According to ANSI, the electrical test with leakage current measurement is performed on helmets that have previously been tested for shock absorption at extreme temperatures of -30 ° C and +60 ° C. Such parameters make it challenging to meet the requirements and pass the test. SECRA helmets passed both tests. 
  2. According to the EN 397 [3] and ANSI Z89.1 [9] standards, shock absorption tests, including the impact test of a helmet with a ram of a certain mass, and specified height, should be performed on the helmet at -30°C. Due to numerous inquiries from customers who perform work in considerably low temperatures, the SECRA helmet was tested positively at a temperature  
    of -40°C. 

The SECRA -2 E40HT helmet is the uppermost achievement in the comprehensive protection of the user’s head, both against arc flash, electric shock, and mechanical hazards.  While a high level of mechanical and electrical protection is a common feature of all SECRA helmets, the new SECRA-2 E40HT integrated visor helmet outclasses all other solutions available in the world in terms of arc flash protection. Additionally, it was the first to surpass the threat protection rating of 30 cal/cm2 and set the bar extremely high, seizing 36 cal/cm2 in an official test at Canada’s Kinectrics Inc lab. The photos taken during the tests and the results are shown respectively in Figures 1 and 2. 

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Fig. 1. Images of the conducted test according to ASTM-2178 

Fig. 2. Test result according to ASTM-2178; the lower graph shows the exceedance of the Stoll-Chianty curve. 

The helmet meets the less restrictive requirements of European standards regarding resistance  
to the effects of an arc flash, the so-called Box Test class 2 [7, 15], with an enormous safety margin,  
as shown in fig. 3 and 4. 

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Image: a few milliseconds after ignition of the arc flash.

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Fig. 3. High-speed camera shots during the GS-ET-29 7 kA test.

Fig. 4. Temperature changes determined with the use of calorimeters during the GS-ET-29 class 2 test. 

The helmet visor is manufactured in the United States. It utilises the latest achievements  
in nanotechnology and material engineering, including the manufacturer’s patented formula  
of nanoparticles that absorb blackbody radiation generated during the ignition of an arc flash.  
At the same time, nanoparticles allow radiation to penetrate in the visible range. Thus, the helmet  
is an example of the balance between the visor’s transparency and its ability to absorb infrared energy in a volume suitable for protecting the user from an arc flash. The new technology used in the visors allowed for excellent colour reproduction. Traditional arc flash visors based their action on colour admixtures which, by blocking thermal radiation, at the same time gave visors a vast, usually green, or yellow tint. It resulted in problematic colour perception for the user. Other advantages of using innovative technologies in the visors of SECRA-2 helmets are increased resistance to ageing caused by UV radiation – nanoparticles do not degrade over time. The scratch resistance of the visor material has also increased. 

All tests of the SECRA -2 E40HT helmet were performed by accredited laboratories: Polish – CIOP, German – ECS, PZT, Westenergie and Canadian – Kinectrics. 

Helmet with the E40HT face shield test was conducted with additional accessories: a flashlight enabling illumination of the workplace and reflective panels. The principal purpose of the test was to determine the degrees of its protection against thermal hazards caused by the action of an arc flash. Both  
in the tests determining the APC (box test) [7,14] and the ATPV – open arc [11] parameter of the face shield, the flashlight and reflective panels were not ignited, which confirmed the safety of their use with the helmet (Fig. 5). 

Fig. 5. SECRA -2 E40HT helmet with an attached flashlight and reflective panels before and after the box test. 

Bibliography 

  1. NFPA 70E – Standard for Electrical Safety in the Workplace; National Fire Protection Association; 2021. 
  2. IEEE 1584-2018 – IEEE Guide for Performing Arc-Flash Hazard Calculations; 2018. 
  3. PN-EN 397:2012+A1:2013-04, Industrial safety helmets. 
  4. PN-EN 166:2005, Personal Eye Protection – Requirements. 
  5. PN-EN 50365:2005, Electrically insulating helmets for work on low voltage installations. 
  6. PN-EN 960:2007, Head mockups for testing protective helmets. 
  7. PN-EN 61482-1-2:2015-04, live working – Protective clothing against the thermal hazards of an electric arc – Part 1-2: Test methods – Method 2: Determination of the arc flash protection class of materials and clothing using a forced and directed arc flash (test chamber). 
  8. Regulation (EU) 2016/425 of the European Parliament and of the Council of 9 March 2016 on personal protective equipment and repealing Council Directive 89/686/EEC. 
  9. ANSI Z89.1-2014(R2019), Industrial Head Protection. 
  10. ANSI Z87.1 Safety Glasses & Eye Protection. 
  11. ASTM F2178 / F2178M – 20, Standard Specification for Arc Rated Eye or Face Protective Products. 
  12. CSA Z94.1-15 (R2020) Industrial protective headwear – Performance, selection, care, and use 
  13. CSA Z94.3-20 Eye and face protectors 
  14. ГОСТ EN 397-2012 Система стандартов безопасности труда (ССБТ). Каски защитные. Общие технические требования. Методы испытаний. 
  15. GS-ET 29:2019-06 “Principles of testing and certification of face shields for electrical work”.