Understanding The UL325 Standard
Underwriter’s Laboratories has been developing safety standards related to the design and manufacture of consumer products for over 100 years. Take a look at most all of your household appliances and electronics systems and you’ll likely see the U.L. Standard for which they comply. U.L. Standards have been developed in conjunction with industry leaders in various product segments as a means to ensure that these products meet certain design criteria necessary to promote a safe environment and reduce injuries to persons. Many U.L. Standards have been incorporated or adopted into the American National Standards Institute (ANSI), National Electrical Code (NEC), and many other national code and development organizations.
U.L. 325 is the standard for Door, Drapery, Gate, Louver, and Window Operators and Systems. The standard was first published in 1973 and has had several updates and revisions over the years with the 6th edition becoming effective January 12th, 2016. To maintain the authorization to mark, products manufactured after this date must be certified to the 6th edition requirements and be labeled as such. The 6th edition is by far the most comprehensive update since the inception of the standard. For the first time, gate operators are required to have 2 independent means of obstruction sensing, both of which must be monitored for presence and operation prior to each gate cycle. Generally, manufacturers will employ some type of inherent sensing system (motor current, etc.) and one type of monitored input (photo beams, etc.) for an external device to comply with these requirements.