Most End Users, Battery Suppliers, Electrical Contractors, and Facilities personnel are unaware of the difference in operation and legal requirements between Emergency Lighting Equipment and other types of battery backup systems.
Emergency Lighting systems are Underwriters Laboratories (UL) listed as Life Safety Equipment and therefore have very stringent requirements that must be met in their construction and performance. Equipment that is to be used for emergency lighting must be listed for this category as determined by the National Electrical Code (NEC), Article 700 and the National Fire Protection Association (NFPA) Code #101. These codes dictate the specifics as to when, where, what, and how Emergency Lighting Equipment shall be used. They also dictate that all Emergency Lighting Systems must have periodic maintenance with records kept on file of this maintenance.
Emergency Lighting Equipment listed by Underwriters Laboratories (under UL Standard #924) must meet performance testing requirements since it will be relied upon to provide a specified amount of power for 90 minutes during a power outage. The UL listing report will indicate which specific batteries the unit is to be provided with and this information is included with the system in the form of markings. If any other batteries are placed in one of these systems, it causes the UL listing to be meaningless. In this case, a Code violation occurs due to these changes.