electric car arc flash clothing

Choosing the right arc flash clothing for electric and hybrid vehicle work

The emerging industry of low carbon vehicles and battery power automotive is presenting occupational hazards more usually associated with electrical switchgear and power cable installation and maintenance.

Whether you are a motor vehicle technician, a training establishment, vehicle recovery, emergency services or first responders, it’s now increasingly likely that you may be exposed to the risk of arc flash.

Arc flash, also known as flash-over, is the light and heat produced as a result of a fault. Normally a short-circuit. Increasing voltages in automotive battery power systems are now a viable source of arc flash.

For all skills and trades working on electric and hybrid vehicles, arc flash clothing can provide a robust defensive layer to the risk of burns from arc flash.

As this hazard is still relatively new in the automotive industry, accurate information can be difficult to locate.

We are often asked for help or advice in selecting Arch Flash Protective Clothing. Customers seek our guidance to recommend or approve the PPE (personal protective equipment) they have selected.

Without knowing the nature of the tasks being undertaken, it’s impossible to make any specific recommendation. However, we can direct the customer in a process of risk assessment which will lead them to selecting to right arc flash protective clothing for their task(s).

The number of variables in activity, procedure and the equipment being worked in, all have a bearing on the choice of clothing.

For example, different vehicle manufacturers use different battery pack voltages i.e. Prius: 201.6 V DC, Tesla: 400 V DC.

The nature of the task being undertaken will also serve to determine clothing choice.

It’s also important to note that while a customer might select clothing based on a specific set of planned tasks, if these tasks change, it’s likely that the protective clothing selection will also need to change, or at least be reviewed to ensure its suitability.

Take the example of an MOT tester who would (in theory) be conducting ‘non-intrusive’ work on an electric vehicle, when compared to a mechanic working for a vehicle dismantler or recycler.

Furthermore, even specific job roles will be required to undertake vastly different tasks i.e. one Vehicle Technician could be undertaking a routine service, while another could be removing or stripping down an AC motor in the drivetrain. These two Technicians would require different Arc Flash PPE as the risks associated with their jobs are different.

Arc Flash PPE has a rating number in cal/cm2 (calorie per square centimetre) (1) and any PPE in use must equal or exceed this number/cal rating.

The difficult part is working out what cal rating you actually need. To do this you must carry out a thorough risk assessment. A separate risk assessment should be undertaken for each different vehicle. Organisations who regularly work on a wide range of electric hybrid vehicles are well advised to catalog all makes and models likely to be worked on, listing the battery and/or AC motor voltages for each (referring to the manufacturers as necessary) and cross checking the various task and the appropriate clothing to be used.
Use an Arc Flash Calculator, then check and double check the results.

To emphasise the importance of this, bear in mind that electric hybrid vehicles are evolving fast. In the near future vehicles will be running 800V DC batteries and future generations of batteries are planned to be in excess of 1100V DC – all with increased power output to the onboard AC motors. Therefore, the huge range of power outputs that needs to be accommodated means that one set of Arc Flash Protective PPE may not be sufficient for every workshop.

Organisations that are robust in their preparations for the increased influx of low carbon vehicles, and who take a proactive approach to risk assessment, training and the acquisition of the right clothing and tools, are the most likely to succeed in keeping their workers safe in the workplace.

While Total Lockout will support and guide as much as possible, the ultimate responsibility lies with the organisation acquiring the equipment.

Furthermore, anyone from a valetor to a senior technician that are, or will soon be working on any electric or hybrid vehicles should be suitably trained and accredited to a level commensurate with the work they are to be undertaking on any vehicle.

To conclude, it’s worth remembering that personal protective equipment is widely understood to be the last line of defence against injury. In the case of electrical systems, isolation, discharge and testing for dead is the ultimate defense. At the same time, it’s acknowledged that some of the work described here can only be carried out with systems live, e.g. MOT Testing. It’s also important to note that there may be some parts of the vehicle electrical system which can hold electrical charge after isolation.

 

(1) A calorie is the energy required to raise one gram of water one degree Celsius at one atmosphere.