UL 464A:2021 PDF Download

1.1 These requirements cover electrically and electronically operated bells, buzzers, horns, and similar audible signal appliances, rated 300 volts or less, for commercial general signaling service and intended for indoor or outdoor locations or both in accordance with the National Electrical Code, NFPA 70.

1.2 These requirements cover audible signal appliances for use in ordinary locations. Audible signal appliances for use in hazardous locations, as defined in the National Electrical Code, NFPA 70, are judged on the basis of their compliance with these requirements and further appropriate examination and tests to determine if they are acceptable for such use.

1.3 These requirements do not cover door bells, buzzers, and chimes used in household and similar applications and intended for operation on Class 2 signal circuits as defined in the National Electrical Code, NFPA 70.

1.4 These requirements do not cover audible signaling appliances intended for fire alarm or emergency communications use as defined by the National Fire Alarm and Signaling Code, NFPA 72.

1.5 A supplemental visual signal incorporated as part of an audible signal appliance shall also comply with the requirements of this Standard.