Requirements and Technical Terminologies in Arc Flash Protection
The dangers of working in environments with risk of Electrical Arc Flash was starkly highlighted in February 2015, when two men tragically lost their lives in an Arc Flash explosion at the Galleria Shopping Centre in Perth. Since then many commercial and industrial electrical companies have reviewed their policies and compliances with regard to Arc Flashes and the required PPE measures available to protect workers.
While managers, owners and safety officers are well aware of the requirements and technical terminology around arc flash protection, it’s just as important that everyone working in these industries and selling PPE have an understanding of the requirements and what steps can be taken to reduce risk.
Here are 5 of the most commonly asked questions:
1. What is an Arc Flash?
An Arc Flash is an explosion, from an electrical source, (eg switchboard) that can cause significant body burns and or death. An Arc Flash ejects pressure and shrapnel and can reach temperatures of 20,000°C.
2. What is a Cal Rating?
A Calorie (cal) rating is the protection factor required to protect the person from 3rd-degree body burns.
3. What is Cal cm2?
Cal Cm2 is the measurement placed upon Arc-rated clothing to demonstrate its protection factor. Each square centimetre of the garment will provide you with the rating stated. EG 9 Cal fabric will provide you with 9-calorie of protection per square centimetre of the fabric.
Put simply, 1cal/cm2 = holding 1 match under your finger for 1 second, similarly, 8cal/cm2 = holding 8 matches under your finger for 1 second.
4. Does a high Cal Rating mean Greater Protection?
Yes. The higher the Cal rating the higher the protection from the garment. It is much better to over-protect than under-protect in an arc flash event.
5. What is the Most Suitable PPE to Wear?
The PPE level is measured by the minimum amount of calories/cm2. There are four risk levels, and the following chart illustrates the 4 PPE levels with corresponding clothing and minimum arc ratings.