Solutions for Improving Arc Flash Safety in Health Care
The dangers of arc flash events in health care are amplified by the possibility for downtime resulting from arc flashes. Downtime in the health care environment is simply not acceptable.
- By Justin Carron
- Nov 01, 2018
In an industry where regulatory compliance is critical and in which the ultimate goal is the delivery of optimal patient care, electricity plays a critical role in providing always-on operation to help facilitate this care. In this environment, which already operates in a life-or-death mindset, arc flash prevention is imperative, and worker and personnel safety are of paramount importance.
The need to ensure arc flash safety has a significant impact on health care facilities, whether it's hospitals or any other environment where patient care is prioritized. Yet many health care providers struggle with how to best address this issue. In an era of constantly evolving codes and standards, doing so has never been more urgent.
In this article, I'll offer best practices for health care providers to make their facilities safer by protecting against arc flash hazards. Additionally, I’ll discuss new technologies that have emerged to help prevent against arc flash hazards and should be considered for any health care provider looking to enhance its arc flash prevention efforts.
Refresher: Why Arc Flash Safety Matters for Health Care
Before diving into some available solutions for preventing arc flash safety in health care, it's important to review just how and why arc flashes can occur in these or any environments.
An arc flash is the explosive energy released when an electrical fault—a short circuit, for instance—causes an arc. This is measured in terms of arc flash incident energy and typically happens when an electric current passes through air as the result of a conductor failure, equipment failure, or the accidental connection between voltage sources such as dropping a tool across buses in distribution equipment.
The explosive energy resulting from an arc flash can be deadly or cause severe injury. The incident energy generated from an arc flash can release temperatures in excess of 36,000 degrees Fahrenheit, which is four times hotter than the sun. Any metals vaporized by the explosion (e.g., copper, aluminum) would also be fatal if inhaled.
The danger of arc flash events is particularly common in power-intensive environments and industries—particularly ones operating with 125 kVA or larger transformers—and health care certainly qualifies. Many health care facilities, especially large hospital campuses, have adopted their own grid systems or microgrids, creating a greater need for arc flash prevention, particularly for personnel tasked with working in these grid environments.
The dangers of arc flash events in health care are amplified, however, by the possibility for downtime resulting from arc flashes. As we've established, health care facilities require always-on power to maximize patient care, and this is literally a life-and-death imperative. Downtime in the health care environment is simply not acceptable.
Best Practices for Arc Flash Safety in Health Care Environments
While arc flash events pose serious risk to health care personnel, these incidents are preventable, and risk can be minimized.
One of the best ways to avoid electrical disasters is to increase the time and distance from arc to the worker, as these are two of the most controllable variables. Reducing the time that an event persists by tripping a breaker or blowing a fuse significantly reduces the arc flash incident energy. Additionally, leveraging remote operation, closed doors, or protective barriers protects workers in case an event occurs by increasing the distance between the arc and the worker.
Another way health care facilities can improve arc flash safety is through better labeling. Arc flash labels indicate two key pieces of information: the expected incident energy (measured in calories per cm2)—at a working distance of 18 inches or 24 inches—which drives the proper personnel protective equipment (PPE) required for protection; and the distance a worker without PPE must work to avoid a non-curable burn (typically measured in feet). By using correct labeling on critical equipment, facilities can get ahead of potential safety issues to ensure personnel are protected.
One of the best ways to help ensure arc flash safety for health care personnel is through better employee education. Workers must be trained and should understand the risks of arc flash safety, including reading and understanding arc flash labels and wearing the proper PPE to perform energized work. Codes and standards are always changing, and it is imperative that organizations be in compliance.
Another way to help minimize arc flash risk is through better equipment. We'll explore this further in the next section.
Existing and Emerging Solutions for Arc Flash Prevention in Health Care Applications
Solutions for reducing arc flash generally involve decreasing fault clearing time, increasing the distance from the arc to the worker, or reducing fault current. Some of the available tools, technologies, and resources for health care facility managers to address arc flash safety include:
- Arc flash studies
- Arc flash training
- Arc flash limiter conversion
- Arc flash relay
- Remote and motorized breaker racking solutions
- Compliant arc flash labels
- Energy-reducing maintenance switches
- Arc-resistant low- and medium-voltage switchgear
- Arc-resistant motor control center (MCC)
Interestingly, one technology has emerged recently that represents a major advancement in the fight to reduce arc flash risk, one that could have a dramatic impact on the ability of health care facility managers to comply with the new OSHA regulation: arc quenching switchgear.
Introduced in 2018, arc quenching switchgear reduces incident energy to a level where the switchgear will survive an arc flash event while providing enhanced safety and minimal equipment downtime. These solutions meet and exceed testing requirements of the "IEEE C37.20.7, Guide for Testing Switchgear Rated Up to 52 kV for Internal Arcing Faults" standard by demonstrating acceptance even when breakers are removed, doors are open, and covers are removed, and without the need for ducts, plenums, or special enclosure construction.
Core features of these products are as follows:
- Third party tested to ANSI/IEEE C37.20.7, Type 2B test guide in standard NEMA 1 construction
- Arc Quenching Device is a UL Recognized Component per UL 2748
- Short circuit withstand rating up to 85 kA at 635 V ac
- Short-time withstand current rating, 85 kA for 30 cycles
- <4 ms arc quenching time
- Current limiting—at least 25 percent reduction in peak fault current
- At least 44 percent reduction in peak system stress
- Complete system self-supervision with health status communicated via Modbus and dry contacts
- Anti-nuisance trip technology
- Engineered-to-order configurations
- UL 1558
- Available in rear access and front access switchgear configurations
- Available in NEMA 1, NEMA 3R, and traditional arc-resistant enclosure types
Arc quenching switchgear meets and exceeds ANSI/IEEE C37.20.7 Type 2B testing requirements with breakers removed and breaker, secondary, or cable compartment doors open, delivering the highest level of arc-resistant protection without the need for ducts, plenums, special enclosure construction, or venting into the room.
In addition to the benefits of arc quenching switchgear in advancing arc flash safety, the technology also minimizes or eliminates damage to switchgear in the event of an arc fault, protecting valuable switchgear assets from arc flash damage. It is designed to reduce peak fault current by at least 25 percent and peak stress on upstream equipment by at least 44 percent when compared to a bolted fault device.
Finally, arc quenching switchgear reduces downtime—an essential factor in health care facilities charged with prioritizing patient care. The solution employs technology that utilizes advanced algorithms to prevent nuisance operation of the Arc Quenching Device (AQD). Should an arc flash occur, restoring service can be accomplished within hours.
Conclusion
Facilities across industries have been driven to improve arc flash prevention efforts, and the health care industry is no exception. By leveraging available tools and resources and exploring new technologies, such as arc quenching switchgear, health care facility managers can help ensure uptime in their patient care facilities while advancing worker safety and maintaining compliance with any current and future regulations.
This article originally appeared in the November 2018 issue of Occupational Health & Safety.