Arc Flash EV Range
For Electric Vehicle Servicing
Arc Flash Statistics
ProGARM revealed that 57% of electrical workers had experienced arc flash, or seen someone else experience it. This is higher than reported statistics and could lead to workers underestimating risk.
The Health and Safety Executive details 15,523 safety-related electrical incidents reported in 2020-2021. Of these, 228 injuries were serious and 13 fatal. At first glance, this percentage does not seem high. However, reported fatalities increased by 69.2% on the previous two years. Since 2016-2017, the total number of events has increased by 7%.
With modern technology and availability of PPE, it is not unreasonable to think statistics would be improving. However, this is not the case. It is important to protect your employees servicing Electric Vehicles (EVs), so we can reduce these numbers.
When does Arc Flash occur?
Electrical safety incidents often occur when equipment such as an Electric Vehicle is being maintained. Accidents can occur when adequate training has not been provided, employees are not supervised or a risk assessment has not been conducted. Some harrowing case studies showing the consequences are available on the HSE website.
How can I protect my employees?
The Electricity at Work Regulations (1989) consists of legislative guidance for employers. Therefore, employers are legally obligated to ensure electrical devices are safe. Regulation 2 specifies “electrical explosion or arcing” as a reason for death or personal injury.
Regulation 4 specifies that systems should be constructed to prevent danger (within reason). They should be maintained in accordance with this. Every work activity should be conducted with the avoidance of danger in mind. As a result, all equipment should be fit for use, maintained and used properly.
Electrical Safety UK also offers practical guidance.
PPE should adhere to IEC 61482-2:2018 regulations. This covers protective clothing against thermal hazards of an electric arc in live working. Specific test methods are used for materials and garments. These are based on textile properties with textile testing methods, also arc thermal resistance properties.
There are two testing methods; the open arc test method (IEC 61482-1-1) and the box test method (IEC 61482-1-2).
Open Arc Testing (IEC 61482-1-1)
This determines the Calorific Value (cal/cm2). A Calorific Value can be Arc Thermal Protection Value (ATPV), Breakopen Threshold Energy Value (EBT), or Incident Energy Limit (ELIM). Garments can be layered and are easy to assess when conducting risk assessments.
Box Testing (IEC 61482-1-2)
This provides a 4kA (APC 1) or 7kA (APC 2, which is higher) protection rating. This is the accepted model within the EU.
What is a Calorific Value?
- ATPV – This represents the maximum thermal energy a garment can withstand before there is a 50% probability of second degree burns
- EBT50 – The level of incident energy where there is 50% chance of breakopen occurring
- ELIM – The maximum thermal energy a garment can withstand, keeping the 2nd degree burns probability at 0%
The Stoll Curve
The Stoll Curve gives a rating of heat energy transfer, using the time of transfer and level of heat energy. The aim of arc flash PPE is to delay the transfer by absorbing heat energy. This is determined by the energy absorbed in cal/cm2 before it reaches your skin, causing a burn. Due to the amount of factors in the environment, the individual, the garment and severity of the incident, a burn is not guaranteed. It is just the most appropriate and accurate test currently to assist in rating garments.