Arc Flash and Electric Vehicles: What Businesses and Workers need to know about Personal Protection

Electric Vehicles (EVs) are one of the world’s hottest topics. With 2,531,206 battery electric vehicles and plugin-hybrid electric vehicles on U.S. roads today,¹ infrastructure, incentives and sustainability are at the forefront of EV discussions.

Within the EV industry, though, the conversation often turns to the perils of working with high-voltage batteries. Workers who build and maintain EVs face numerous dangers on the job, but arc flash incidents are the most acute. Even deadly.

What is arc flash? It’s an energy discharge of light and heat that forms when a fault occurs in an electrical circuit. A tremendous amount of energy is released as current flows through ionized air. When an arc fault occurs, the massive electrical explosion can reach 35,000° Fahrenheit – 4 times hotter than the sun! The intense heat causes a sudden expansion of air, which can result in a blast with exceedingly strong air pressure.

This force can be significant and can blow workers away from the arc, causing falls and injuries that may be more severe than burns. In sum, there are 2 separate byproducts of the electrical explosion: arc flash (the light and heat) and arc blast (the pressure wave that follows). It’s vital for workers to wear personal protective equipment (PPE) in any environment where arc flash is possible.

Arc flash incidents most often occur in electricity and power plants, or any place that uses electrical equipment such as substations and transmission lines. EV battery and manufacturing sites are now added to that list.

The risks of arc flash are especially great when handling EV batteries, which can contain hundreds of volts of electricity. Risks are increased since EVs use high-voltage, high-energy density lithium-ion batteries. These batteries consist of many individual, low-voltage cells, several of which are connected. For example, certain models of Tesla’s EVs have more than 7,100 battery cells. Each cell has a voltage that can vary, but typically when fully charged, will be about 4.2Vdc. Even with a low value of charge, the cell can have a voltage of 3Vdc. These batteries can produce voltages approaching 1,000Vdc and can produce arc flash currents of thousands of Amps.² Collectively, these batteries provide enough voltage to propel a vehicle.³

WHAT CAUSES ARC FLASH?

There are many reasons arc flash may occur. It is not necessary to touch live components to sustain an arc flash injury. Common causes include:

THE PERILS OF ARC FLASH

During an arc flash explosion, serious and/or deadly conditions can arise. Typical dangers include burns, fire, flying objects (molten metal and shrapnel that exceed 700 mph), blast pressure (upwards of 2,000 lbs. /sq. ft.), sound blast up to 140 dB, and exorbitant heat (about 35,000° F). Further outcomes can include eardrum
damage, which starts at 720 lbs./sq. ft., and lung damage, which typically begins at 1,728 lbs./sq. ft.⁵

PPE TO HELP PROTECT WORKERS

Workers handling EV batteries should be properly trained and equipped to perform their tasks safely. This includes donning PPE designed to protect against possible arc flash and other hazards. When working with EVs, it’s essential to follow safe work practices. This may include procedures for isolating the electrical system, conducting electrical safety tests, disconnecting battery links to reduce incident energy and correctly utilizing PPE.

Choosing the right PPE for your team is equally important. Honeywell Salisbury manufactures pioneering patented electrical safety products that help protect workers from arc flash hazards while handling high-voltage components and batteries. From balaclavas to leather over gloves, Honeywell Salisbury is a long-standing and trusted resource for electrical safety protection.

For head, face, and neck protection against arc flash, Honeywell Salisbury’s new PrismShield™ Plus has a frameless design to increase a worker’s viewing area by more than 20%. The face shield has a ProLift shroud and lift-front hood, plus a double-curved lens that greatly reduces distortion and eye strain. The weight- balancing frame also increases comfort by reducing neck strain.

When a worker needs rescuing, the Insulated Rescue Stick is an invaluable tool for any workplace. It’s used to safely withdraw an injured worker out of a hazardous area without endangering the rescuer. It can be used for rescues in battery manufacturing and assembly, confined spaces and vaults, as well as rescues near electrical cabinets and switch gear. 

Hand protection is also critical when working with electrical safety hazards. Honeywell Salisbury’s Class 0 Electrical Insulating Rubber Gloves provide cut and abrasion protection. They’re extremely flexible, making it easy to work with small parts. The gloves meet or exceed ASTM D120 and IEC EN60903 Standards.

ILP Series Leather Glove Protectors provide enhanced protection for rubber insulating gloves, both of which must be worn together while working near electrical hazards.

INSULATED TOOLS AND COMPLIANCE

Specific tools must be used when working with EVs. The National Fire Protection Association (NFPA^®) 70E standard requires insulated tools such as these be used when working on or near electricity greater than 50V. Two of Honeywell Salisbury’s latest EV insulated tool kits include the EV124: Electric Vehicle Master Shop Kit for organizations working with larger electric trucks, buses and military vehicles. The TK84: Honda Civic and Accord EV Kit was developed alongside Honda engineers.

Ultimately, electrical safety is a shared responsibility between employers and employees. Compliance with safety regulations is paramount and requires a collaborative effort between workers and management, with the end-goal of preventing worker injury. The right PPE is a substantial part of the solution as the world moves toward an electrified future—safely.

¹ https://earthweb.com
² https://www.linkedin.com
³ https://www.engineering.com
⁴ www.safetyandhealthmagazine.com
⁵ https://www.osha.gov