Other tools NBS offers a range of tools for specification and collaboration National BIM Library The most trusted BIM Library in the UK, certified to the internationally-recognised NBS BIM Object Standard Uniclass 2015 A dynamic and unified classification system for the construction industry covering all sectors Construction Information Service (CIS) A comprehensive online collection of construction related standards, regulations, technical advice and articles Plug-ins NBS provides a range of tools to help connect your CAD model to your specification model
Platform Resources Support Events About TheNBS.com Manufacturers Uniclass 2015 Get in touch

Platform

NBS Chorus Features and pricing Book a demonstration Sign in to NBS Chorus Other tools National BIM Library Uniclass 2015 Construction Information Service (CIS) Plug-ins

Resources

Knowledge Sample Specification Case studies Authors

Support

Training Downloads and updates

About

About NBS Newsroom

Platform

NBS Chorus Features and pricing Book a demonstration Sign in to NBS Chorus Other tools National BIM Library Uniclass 2015 Construction Information Service (CIS) Plug-ins

Resources

Knowledge Sample Specification Case studies Authors

Support

Training Downloads and updates

About

About NBS Newsroom

UL 1449-21 Surge protective devices

Publication Year

2021

Document Status

Current

Abstract

Specifies enclosed and open-type Surge Protective Devices (SPDs) designed for repeated limiting of transient voltage surges.

Document History

Revised December 15, 2022. Supersedes UL 1449-14.

Publisher Information

Underwriters Laboratories

Established in 1894 as the Underwriters' Electrical Bureau, UL is a global safety consulting and certification company, approved to perform safety testing by the U.S. federal agency of Occupational Safety and Health Administration.

333 Pfingsten Road
Northbrook
UL
USA

Tel: +1 877 854-3577