Mitigating Arc Flash Injuries Through Remote Wireless Cutting

Using a wireless remote, workers can communicate via Bluetooth connection with the tool and initiate a cut from a safe distance. Image courtesy of Milwaukee Tool.

The pairing of a cutter and a wireless remote creates a safer energized conductor cutting process for crews.

Contributed By: Milwaukee Tool

Arc flashes – they’re brighter and hotter than the sun, louder than a jet, and capable of creating arc blasts that could send metal debris flying at over 700 miles per hour. Determining the maximum energy associated with an arc flash requires complex calculations and advanced computer programs – and even then, experts still disagree on the actual explosive capabilities of an arc flash when applied to an actual jobsite setting. There is one thing all experts will agree on, though – it’s extremely hazardous to be anywhere near an arc flash when it occurs.

The only ideal method to cut an energized conductor from a safe distance is to completely remove the physical connection of the worker to the cut area. An indicator light on the wireless remote alerts the user immediately after the tool is done cutting. Image courtesy of Milwaukee Tool

Electric arcing can produce temperatures as high as 35,000° Fahrenheit – nearly four times as hot as the surface of the sun. Even though this intense heat can last for just a fraction of a second, it’s enough time to cause severe burns, potential hearing loss, blindness, skin damage from blasts of molten metal and copper, lung damage and blast injuries from shrapnel, and even death. All of this is why the Occupational Safety and Health Administration (OSHA), the Institute of Electrical and Electronics Engineers (IEEE), and the National Fire Protection Association (NFPA)have drawn up three major industry standards associated with arc flash:

• OSHA 29 Code of Federal Regulations Part 1910 Subpart S
• NFPA 70E
• IEEE Standard 1584

NFPA 70E, in particular, has been influential in directing safety-related practices and maintenance requirements for jobsites that have the potential of arc flash incidents.

But despite the effectiveness of these requirements, there remains the unfortunate fact that arc flash is unpredictable. In a report by the IEEE, the organization stated, “Workers and equipment may be at risk from electrical arc, even at times when codes, standards, and procedures are seemingly adequately addressed,” and that “workers should ‘assume the worst and use available personal protective equipment.” Simply put – the unpredictable nature of arc flash accidents is why it is so important to know about them and stay away from dangerous situations.

THE IMPACT ON YOUR CREW & COMPANY

According to OSHA standards, an arc flash incident only needs to be reported if (A) A fatality occurs or (B) Three or more employees require hospitalization. With that in mind, it’s not a stretch to assume that current data does not capture the full landscape of arc flash risks and incidents occurring each day. This inconsistent reporting practice has led to a wealth of conflicting data on the frequency of arc flash accidents, with figures ranging from 5 – 10 per day to 30,000 per year. These reports also estimate that those incidents result in an average annual total of 7,000 burn injuries, 2,000 hospitalizations, and 400 fatalities per year. In fact, according to the Bureau of Labor Statistics about 80% of these incidents involve “qualified workers,” showing that even trained experts can get hurt – another reminder of the unpredictable nature of arc flash.

A handle and hang hook suspend the tool in vaults and manholes . Image courtesy of Milwaukee Tool. The overall design of this underground cutter also enables crews to easily set it up within a vault, manhole, or trench, make the cut, and reset quickly for the next cut. Image courtesy of Milwaukee Tool.

THE SAFEST SOLUTION – CUTTING CONDUCTORS FROM A DISTANCE

With all this data considered, the goal for any arc flash mitigation technique is to reduce contact with the conductor being cut as much as reasonably possible. PPE and proper training are critical for protection but, as detailed earlier, an arc flash accident can still occur despite the preparation and expertise of those involved.

Historically, the methods to make a cut on a potentially live conductor have tried to create space between the worker and the cut, but ultimately these methods don’t safely distance workers enough.

The most common method – utilizing a hydraulic pump – in theory protects workers from any potential conductive path. However, if debris got into the hydraulic pump’s hose it’s possible that the conductive path could still be intact. In addition, most hydraulic pumps still require that users physically press the button to operate them, thus maintaining the physical connection between the worker and the live line.

Many companies have already started to implement remote devices for maintenance operations such as monitoring, control and diagnostics, and racking. This same approach is needed for the actual cutting of the potentially energized conductor. The pairing of a cutter and a wireless remote creates a safer cutting process for crews. Using a wireless remote, workers can communicate via Bluetooth connection with the tool and initiate a cut from a safe distance. An indicator light on the wireless remote would then alert the user immediately after the tool is done cutting.

Only the paired wireless remote can initiate the cut, eliminating the potential for other devices to connect to the tool and initiate a cut unintentionally. Additionally, for wrecking or new line installs, the tool can easily interchange between remote mode and local mode through a Remote Cut Switch on the back of the tool.

The overall design of this underground cutter also enables crews to easily set it up within a vault, manhole, or trench, make the cut, and reset quickly for the next cut. A handle and hang hook suspend the tool in vaults and manholes and a top handle keeps users’ wrists in a neutral position to improve wrist posture and decrease muscle effort when a remote cut is not needed. The open scissor-style jaws provide easier set-up in trenches, allowing users to easily scoop up the conductor to prepare for the next cut.

The M18™ FORCE LOGIC™ 3″ Underground Cable Cutter w/ Wireless Remote utilizes wireless technology to keep workers further away from the cut. Image courtesy of Milwaukee Tool.202

BOTTOM LINE

Arc flash accidents can be hugely detrimental for crews and the companies they work for – causing serious bodily harm or fatal injuries to large fines and expensive lawsuits. Though no combination of countermeasures can eliminate the risks altogether, initializing remote work throughout the entire process of cutting an energized conductor vastly improves the safety of those doing the work. ESW

The Milwaukee Tool M18™ FORCE LOGIC™ 3″ Underground Cable Cutter w/ Wireless Remote utilizes wireless technology to keep workers further away from the cut. Currently, this is the leading technology of its kind – offering physical separation between the worker and the energized conductor. Learn more at www.milwaukeetool.com.

References

1. Campbell, R. B., & Dini, D. A. (2015, March). Occupational Injuries from Electrical Shock and Arc Flash Events. Retrieved from nfpa.org
2. Electrical Safety in the Workplace. (2012, April). Retrieved from osha.gov
3. Arc Flash Research Project. (n.d.). Retrieved from https://standards.ieee.org/content/ieee-standards/en/ products-services/arcflash/
4. [2019 Statistics] Arc Flash Explosions Occur Every Day – Arc Flash Accidents. (n.d.). Retrieved from https:// allumiax.com/blog/2019-statistics-arc-flash-explosions-occur-every-day-arc-flash-accidents
5. Department of Labor. UNITED STATES DEPARTMENT OF LABOR. (n.d.). Retrieved from https://www.osha. gov/harwoodgrants/grantmaterials/fy2007/sh-16615-07
6. (2019, March 7). Top 10 Arc Flash Statistics Every Employer Should Know. Retrieved from http:// falconpowerconsultants.com/top-10-arc-flash-statistics-every-employer-should-know/