UL 2250-2017 pdf free download

UL 2250-2017 pdf free download.Instrumentation Tray Cable.
14.3 The energy that an optical-fiber cable carries in some laser systems presents a potential risk of eye, or other injury to people. Consequently, where optical-fiber cables are installed in a laser system, the recommendations of the ANSI Z136 laser system safety standards should be applied. To help protect optical-fiber cable installers, users, service personnel, and anyone who handles the optical-fiber cable component of the system after installation, 43,1 specifies a tag, reel, or carton marking.
15 Assembly
15.1 Optical-fiber member(s)
15.1.1 Optical-fiber member(s) alone shall not Constitute a cable. One or more optical-fiber members may be included in a cable. Optical-fiber members may be grouped with or without electrical conductors. Optical-fiber members in a cable shall be cabled alone or as a group with the same direction and with the same length of lay as the electrical conductors. In the performance of the cable, each optical-fiber member is to be considered as a filler. A group of optical-fiber members without any electrical conductor(s) in it may ncIude one or more non-current-carrying metal parts (earth-grounded or interrupted when the hybrid cable is installed) such as a metal strength element or a metal vapor barrier. The construction of these parts is not specified. Each such part shall be physically and electrically isolated from any bare grounding conductor in the cable.
15.2 Circuit and grounding conductors
15.2.1 All of the circuit conductors and insulated grounding conductors shall have the same voltage rating. Insulated conductors with different temperature ratings may be mixed in a given cable if the cable is rated for the lowest temperature rating of any of the constituent insulated conductors.
15.2.2 Two or more insulated conductors shall be assembled in a cable. Sizes may be mixed. A cable may contain precabled groups of conductors as described in 15.2.4.
15.2.3 In a cable, the conductors, and any grounding conductor, bare or insulated. may be cabled (round cable — see 15.2.4) or laid parallel (flat cable).
15.2.4 The conductors in a round cable shall be cabled with a length of lay that is uniform throughout the length of the cable and is not greater than indicated in Table 15.1. Grouping of the circuit conductors into pairs, triads, quads, and other precabled subassemblies is not required but Is acceptable if the length of lay of the conductors in each group and of the groups in the overall assembly comply with this paragraph and with Table 15.1. The direction of lay may be changed at intervals throughout the length of the cable. The intervals need not be uniform. In a cable in which the lay is reversed:
a) Each area in which the lay is right- or left-hand for several (typically 10) complete twists (full 3600 cycles) shall have the insulated conductors or precabled groups of insulated conductors
cabled with a length of lay that is not greater than indicated in Table 15.1, and.UL 2250-2017 pdf free download.