Assure Electrical Service Entrance Safety

Service entrance safety switches that comply with NEC and UL standards will effectively protect electrical workers.

By Arthur Jur, Eaton

The importance of prioritizing safety for those working near electrical equipment cannot be overemphasized. It’s essential that proper measures be put in place to protect workers from risks such as shock, electrocution, burns, fires, and explosions. This is especially important at electrical-service entrances, which are generally considered to be one of the most dangerous points in a power-distribution system because they typically have the highest available fault current in the facility.

To help organizations advance safety for electrical workers, important code changes for the electrical-service entrance were adopted in recent years. In 2020, the National Electrical Code (NEC, nfpa.org/codes-and-standards/nfpa-70-standard-development/70) modified its requirement for barriers to be included in all service equipment and relocated the code under 230.62(C). The NEC also expanded the types of service equipment to which the code applies. While the original code covered panelboards, switchboards and switchgear, the 2020 modification covered all types of service equipment, including enclosed disconnect switches. In the modified language, the NEC also specified the need to prevent incidental contact when the door is open.

UL builds on NEC

While the NEC addresses equipment installation, global safety science company UL Solutions, Northbrook, IL (ul.com), is tasked with determining how a product should be constructed to help ensure a safe working environment. As part of its role to certify the safety of electrical products, UL Solutions addressed the NEC change in 2022, updating the UL 98 standard to ensure that enclosed and dead front switches are constructed and tested to be compliant with the new NEC code. UL Solutions identified a gap, which gave the organization the opportunity to define what constitutes incidental content and outlined compliance based around a specific probe design. If the probe touches a live part, then the equipment fails; if it doesn’t, it passes.

The intent behind the code modifications is to protect those who work around service-entry equipment from inadvertently contacting line terminals such as uninsulated, ungrounded service busbars or service terminals within an enclosure. The code facilitates the application of proper line-side barriers in all service-entrance equipment to help reduce risk of arc flash and shock for service workers.

Safety switches incorporating NEC- and UL-compliant barriers help enhance protection for service workers in applications beyond the service entry.

Line-side barriers

While a safety switch can be applied in many different applications, the electrical-service entrance represents one of the most critical. Often installed at the point on a building where the utility delivers power, these devices can serve as the main disconnect switch for the site. Because an electrical worker may be required to access service-entrance equipment to perform work such as replacing a wire or fuse inside the enclosure, it’s important to adequately shield personnel from live power on the line side.

A UL 98-compliant barrier within the safety switch is intended to prevent electrical safety hazards such as a worker accidentally placing their hand or tool in the wrong location. We believe it is vital to make sure safety switches are compliant with NEC 230.62(C) code and updated UL 98 requirements when applied at the service entrance. Some manufacturers have begun designing a small portion of their safety-switch models to accommodate UL’s new specifications, while others are simply offering retrofit kits that must be purchased separately.

Regardless of application, we recommend that you only incorporate safety-switch solutions that are engineered with NEC- and UL-compliant barriers. Not only do these barriers meet the specific conditions outlined in UL 98, but they can help optimize safety for workers in applications beyond the service entry.

Embrace codes and standards

For years, the NEC has pioneered stronger protections for those who work on service equipment and UL has followed suit with stringent certifications for electrical-safety products and service-entrance equipment. As the minimum set of rules that must be followed for compliance, the NEC requirement for barriers in service equipment and related UL standards provide assurances that personnel remain safe from potential electrical hazards.

It’s vital to make sure safety switches are compliant with NEC 230.62(C) code and updated UL 98 requirements when applied at the service entrance. This is why we’ve standardized UL 98 compliant line-side barriers across our entire lineup of general and heavy-duty safety switches. EP

Arthur Jur is a Senior Engineering Manager at Eaton Corp., Fenton, MO (eaton.com) where he leverages 27 years of electrical-industry expertise to help innovate electrical switchgear product design. Jur currently maintains and has held multiple leadership positions across electrical safety standards working groups and has vast experience across low-voltage electrical product applications.