What is UL 1449?
Underwriters Laboratories standard UL 1449 has become the primary safety standard for surge protective devices (SPDs). It describes the materials and installation requirements for SPDs used for the protection of AC electrical circuits.
The standard has been revised twice in the past few years. A major safety testing initiative (UL 1449 2nd edition) became effective February 2007, and additional administrative and methodology changes (UL 1449 3rd edition) became effective in September 2009. The 3rd edition also includes new independent performance testing requirements.
UL 1449 3rd edition completely supersedes preceding editions. From September 2009 on, all equipment brought onto the market must satisfy these new requirements in order to qualify for the UL label.
Practically all North American surge standards now revolve around 3rd edition, and are now purposely aligned with other standards, including UL 1283, 2008 National Electrical Code™ Article 285, NEMA LS-1, ANSI/IEEE C62 documents and others.