Avoiding Injury, Damage, Downtime, And Non-Compliance Requires Professional Analysis And Action
On the morning of March 30, 2023, an electrician working for an Indiana-based die-cast mold manufacturer suffered severe electrical burns to his upper body as he attempted to remove a 480 V bus plug while the fuse was still in an active circuit. Sadly, the accident proved fatal to the worker.
Arc flash injuries and deaths are all too common in municipal, institutional, and industrial environments. A news release from the Bureau of Labor Statistics dated December 19, 2023, offered grim statistics – in a U.S. national census of fatal occupational injuries arising from exposure to electricity, 749 workers lost their lives in the period 2018 – 2022. One can conclude the number of non-fatal worker injuries during this period was many times this number.
The severe impact of arc flash incidents is not limited to the workers involved and their families – damage to equipment, lost production, and insurance and legal consequences often impose onerous financial costs and hardship for companies, their employees, and others.
Characteristics of an Arc Flash
An arc flash is an instantaneous release of energy arising from an electrical arcing fault. Arc flash temperatures can exceed 35,000 degrees F at the arc terminals, vaporizing conductors and blasting molten metal and plasma with explosive force. Intense radiant heat causes nearby objects (and people) to absorb this energy and can instantly heat them to vaporizing temperatures. UV, visible, and infrared light, and the sound wave emanating from the arc can cause severe eye and ear damage, including permanent blindness and deafness.
Common Causes of Arc Flash
Most instances of arc faults are attributed to:
- Workers who ignore, are unaware of, or fail to practice safe operating procedures
- Use of unsafe tools, dropping tools, and incidental contact with ‘hot’ conductors
- Insulation failure
- Condensation, dripping water, and corrosion
- Accumulation of dirt and contamination
- Loose electrical connections, unprotected live components, and defective equipment
- Inadequate inspections and maintenance of the electrical system
Further, the increasing adoption of renewable energy systems and microgrids and their integration into existing power grids introduce new challenges and risks for arc flash protection and safety (notably, bidirectional energy flow, islanding, and synchronization issues).
Conducting an arc flash study under the direction of certified professionals employing the latest flash detection and protection methods and technologies effectively reduces the risks involved.
Arc Flash Studies are Mandatory
Undertaking an arc flash study/analysis is an indispensable requirement for safely operating a backup power supply. Electrical safety in the US and other countries is a legal mandate. Thus, installing a new electrical backup system or upgrading an existing system triggers the need for proper engineering analysis to protect workers, property, and operations. Regulations governing such studies include NFPA Standards 70E and IEEE 1584 – Guide for Performing Arc Flash Hazard Calculations.
Arc flash studies calculate arcing fault current, incident energy (the amount of thermal energy impacting a surface at a given distance during an electrical arc event), and arc flash boundaries. Ultimately, they identify problem areas and mandate electrical equipment labeling to notify workers about the voltage, incident energy value, working distance, arc flash boundary, and the appropriate personal protective equipment required to work on the equipment.
What’s Involved With an Arc Flash Analysis
Undertaking an arc flash study/analysis is an indispensable requirement for safely operating a backup power supply. Electrical safety in the US and other countries is a legal mandate. Thus, installing a new electrical backup system or upgrading an existing system triggers the need for proper engineering analysis to protect workers, property, and operations. Regulations governing such studies include NFPA Standards 70E and IEEE 1584 – Guide for Performing Arc Flash Hazard Calculations.
Conducting an arc flash study of an electrical backup system requires specialized software, data collection, and analysis by qualified professionals who undertake some or all of the following steps:
- Updating one-line diagrams to display the entire power distribution layout (power sources, voltages, and electrical equipment)
- Gathering data to confirm the information shown on one-line diagrams and re-create missing diagrams by thoroughly reviewing all the equipment, ratings, nameplate data, trip settings of protective devices, and size and length of conductors
- Modeling the power system using engineering modeling software such as ETAP for analysis
- Short circuit analysis to determine if protective devices are properly rated to withstand a bolted (i.e., a solid connection, no additional impedance) short circuit fault
- Protective device coordination study to confirm that protective devices, such as circuit breakers,
- operate in a correct sequence in the event of a fault to avoid shutting down critical equipment
- reduce arc flash hazards at various locations (or require changes to existing settings on breakers and relays)
- Arc flash hazard (incident energy) analysis using calculations performed in accordance with IEEE and NFPA standards
- Writing reports that inform the facility owner of results and recommendations
- Applying appropriate labeling to electrical equipment to highlight arc flash energy levels, PPE requirements, arc flash boundary, and working distance for the equipment
A licensed professional electrical engineer is commonly required to certify the engineering report and study. Arc flash studies require updating whenever modifying an electrical system, and such studies need to be reviewed every five years.
Maintaining up-to-date studies is the only way to ensure the electrical system information is reliable. Lives depend on it…
We Can Help Keep Your Workers and Backup Power Systems Safe
Conducting arc flash analyses of your backup power systems is a mandatory first step in keeping your workers safe. There’s simply no room for getting it wrong.
At Global Power Supply, we have the expertise and technologies to plan, organize, conduct, and follow through with thorough arc flash studies of your backup power systems the right way.
And our services don’t stop there.
Contact us today to learn how we can assist you onsite to implement the action steps directed by our studies to ensure your system is compliant with regulations and safe to operate.