Auto Service World
News   August 8, 2023   by Mark Sessions

EV World: Safety and success

High-voltage training is essential for technicians’ safety — and your shop’s success

As the number of electrified vehicles (EVs) on the road continues to rise, the number making their way into repair shops is steadily increasing as well. With EV sales forecasted to account for 50 percent of new car sales by 2033, the repair shops that will thrive in the future will be the ones whose technicians know how to service new technologies — and importantly know how to do so safely.

The responsibility to train employees in safe working practices is paramount for any business. When it comes to EV repair and maintenance, technicians often come in with a misunderstanding of what the dangers really are.

Electrified vehicles are engineered and built to meet vehicle safety standards and undergo the same rigorous safety testing as conventional internal combustion engine (ICE) vehicles. These standards ensure that the high voltage system is safe for drivers, passengers and anyone who encounters them. There can be dangers, however, if multiple isolation faults occur within a vehicle.

As a trainer for ZF Aftermarket, I teach high-voltage training that equips technicians with the proper knowledge and procedures to work on electric vehicles safely. ZF’s training applies to any and every EV application and is built on the foundation of the Occupational Health & Safety Act, the German Road Vehicle and DGUV 200-005 regulations. These standards for employee and public safety cover every aspect of working on battery-operated vehicles, guiding the technician to work to the highest safety standards, using specific work-based instruction.

Now adapted for North America, the training integrates the elements of the NFPA-70E regulation in a combination of online and in-person, hands-on sessions. Certification is active for two years from the date of completion.

Pure battery-electric vehicles, plug-in hybrids, and hybrid electric vehicles have high-voltage electrical systems that typically range from 300 to 850 volts. Importantly, bodily contact poses a danger to health in as little as over 60 volts DC or over 30 volts AC. Exposure is directly affected by bodily resistance and the skin’s moisture content. This resistance has a direct influence on the amount of electrical current that could pass through the body, and the severity of the outcome is directly proportionate to the amount of time the technician is exposed to the current and possibly the frequency.

One additional important consideration is that these vehicles will continue to operate with one isolation fault on the high-voltage circuit; the vehicle will warn the driver and continue to function normally until it comes to a complete stop. If a second fault occurs, the vehicle will deactivate as soon as it is detected. Even then, the ground or PE (protective Earth) circuit is constructed in such a way as to prevent the risk of injury. This is important because a technician can be at risk when working on a system that has a PE and an isolation fault. But this risk can be safely negated by following proper procedures.

ZF’s five-stage process of what we call a Certified Deactivation of the high-voltage system must be followed to ensure the technician’s safety. This includes specific signage, labelling, lock-out tag-out procedures & NFPA-70E Reg. Personal protective equipment and importantly, the passive discharge time of any remaining energy stored in the system capacitors.

Once the system is safely and properly deactivated, it is essential to inspect it by identifying and correctly using precise measuring equipment to define any system tolerance defects. This allows for accurate diagnosis and repair of any faults, clearing the way for the safe installation of any replacement components before final re-activation.

Of course, no job is complete without a detailed report that defines the original state of the vehicle, with all measurements and findings, as well as the condition in which it was handed back to the customer. Understanding the need for accurate and concise historical data is key to a quality work structure.

Electric vehicles pose new challenges and requirements, but they are cleaner and require significantly fewer moving components than traditional ICE vehicles, offering consumers a more sustainable mobility experience. Aftermarket shops and technicians should be preparing now for a future dominated by EVs. There’s no better place to start than with high-voltage training to ensure your employees’ safety on the job.

Mark Sessions is senior product technical trainer and ZF high voltage expert for ZF Services North America.

This article originally appeared in the Summer issue of EV World

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