Navigating the UL Safety Requirements for Surge Protection

Overview:

Specifiers and users of Surge Protective Devices (SPDs) are adjusting to new terminology and requirements. UL revised their 1449 Safety Standard for Surge Protective Devices to increase safety. The National Electrical Code (NEC) incorporated specific language to require the use of these safer products. This tip sheet will explain some of the changes affecting specifiers and users.

The NEC is a regulatory requirement for installing most new electrical equipment. OSHA has more impact on the operation of the equipment after installation. They both effectively require safe products for surge protection.

NEC Section 285.5 states, "Listed. An SPD(surge arrester or TVSS) shall be a listed Device." If the installation has to meet the NEC, the SPD has to be listed. Electrical inspectors have the obligation to reject installations not meeting this requirement. Installers and users can have liability issues if they don't comply with the NEC.

NEC Section 100 defines "Listed" as, "Equipment, materials, or services included in a list published by an organization that isacceptable to the authority having jurisdiction and concerned with evaluation of products or services, that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services, and whose listing states that either the equipment, material, or service meets appropriate designated standards or has been tested and found suitable for a specified purpose."

Electrical inspectors oftentimes require UL listings rather than listings from other test organizations. UL has been very actively involved with electrical safety. UL knows the limitations inherent with their own test standards. They promptly investigate any counterfeiting or unauthorized use of their listing marks.

NEC Section 110.3(B) describes the installation and use of equipment. "Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling." That means the UL listing and installation instructions effectively have the weight of the NEC behind it. This is why UL requirements are so important with SPDs.