- Hot search：
UL 217-2020 pdf free download
UL 217-2020 pdf free download.Smoke Alarms.
22.1 For an alarm that is intended to be connected to a separate remote power supply such as a transformer, the supply cord is not required to be factory wired to the alarm or to the transformer terminals or leads when the manufacturer’s published instructions provided with the unit are explicit regarding the method of connection. The minimum size conductors between the alarm and remote power supply shall not be less than 0.82 mm2 (18 AWG) and shall not be longer than 6.1 m (20 ft). The interconnecting wiring is to be provided with the alarm and the transformer by the manufacturer.
22.2 Where longer runs of interconnecting wiring are used in an installation, such as in a multiple station configuration, or where several alarms are supplied by a common power supply, the wiring is not required to be provided by the manufacturer. However, the installation wiring diagram or manufacturer’s published instructions shall be marked to specify that the wiring to be used shall be in accordance with the provisions of Articles 210 and 300.3 (B)of the National Electrical Code, ANSI/NFPA 70. Additionally, the resistance of the interconnecting wiring shall be a maximum of 10 ohms, unless otherwise specified by the manufacturer.
23 Internal Wiring
23.1.1 The internal wiring of a smoke alarm shall be routed away from moving parts and sharp projections and held in place with clamps, string, ties, or the equivalent, unless the wiring is determined to be rigid enough to retain a shaped form. The internal wiring shall consist of conductors having:
a) Insulation rated for the potential involved
b) Insulation rated for the temperatures to which they are subjected: and
c) The current-carrying capacity for the service.
23.1.2 Leads or a cable assembly connected to parts mounted on a hinged cover shall be of sufficient length to permit the full opening of the cover without applying stress to the leads or their connections. The leads shall be secured or equivalently arranged to prevent abrasion of insulation and jamming between parts of the enclosure Wire shall be stranded copper.
23.1.3 When the use of a short length of insulated conductor is not feasible, such as for a short coil lead or the like, electrical insulating tubing shall be used. The tubing shall not be subjected to sharp bends. tension, compression, or repeated flexing and shall not contact sharp edges. projections, or corners. The wall thickness of the tubing shall comply with the requirements for such tubing except that the wall thickness at any point for polyvinyl chloride tubing of 9.5 mm (3/8 in) diameter or less shall not be less than 0.43 mm (0.017 in). For insulating tubing of other types, the wall thickness shall not be less than that required to at least equal the mechanical strength. dielectric properties, and heat and moisture resistance characteristics of polyvinyl chloride tubing having a wall thickness of 0.43 mm (0.017 in).UL 217-2020 pdf free download.
All resources on this website are from the Internet. It is only for personal study and research. No one is allowed to use it for any commercial purpose. If you need, please buy the genuine standard. If there is any infringement of your copyright, please contact the webmaster in time, and I will correct it immediately.
- Maybe you like
- Latest Updates
- ISO 287-2009 pdf free download
- ISO 527-5-2009 pdf free download
- ISO 659-2009 pdf free download
- ISO 660-2009 pdf free download
- ISO 712-2009 pdf free download
- ISO 725-2009 pdf free download
- ISO 730-2009 pdf free download
- ISO 927-2009 pdf free download
- ISO 2041-2009 pdf free download
- ISO 3040-2009 pdf free download
- ISO 3506-2-2009 pdf free download
- ISO 3506-3-2009 pdf free download