Surge Protective Devices and UL 1449 4th Edition

The most recent revision to UL 1449 is known as 4th Edition. It went into effect on March 11, 2016, and has been accepted as an American National Standard (ANSI). The purpose of this document is to summarize the major changes to surge protection standards and identify the key terms that should now be referenced when talking about or specifying any surge protective device.