1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULUNDERWRITERS LABORATORIES INC. CERTIFICATION REQUIREMENT DECISIONThis Certification Requirement Decision is prepared by UL LLC. It is normative for the applicable ULProduct Certification Program(
2、s); however, it is currently not part of the UL Standard(s) referencedbelow.Product Category (CCN): PWVXStandard Number: UL 719Standard Title: Standard for Nonmetallic-Sheathed CablesEdition Date: September 8, 2015Edition Number: 13Section / Paragraph Reference: Revised 3.10, 4.3.2, 4.4.1, 4.6.1.1,
3、4.6.2, 5.6.1, 5.14,5.15, 5.16, 7.12.2, 7.15, Table 1; New 4.6.1.3, 4.6.2.2, 4.6.2.3, 6.1.16, 6.1.17, 6.1.18,6.2.11Subject:NM-PCS cableDECISION:3.10 SIGNAL/CONTROL CONDUCTORS Conductors installed as Class 2 and Class 3 in accordancewith Article 725 of the National Electrical Code(NEC).3.10 11THERMOPL
4、ASTIC - a polymeric material that repeatedly can be softened by heating andhardened by cooling through a temperature range characteristic of the material, and that in the softenedstate can be shaped through the application of force.4.3.2 A copper circuit conductor shall not be smaller than 14 AWG an
5、d shall not be larger than 2 AWG.An aluminum or copper-clad aluminum circuit conductor shall not be smaller than 12 AWG and shall notbe larger than 2 AWG. Signal/control conductors used within a Type NM-PCS cable shall be 18 or 16AWG copper.4.4.1 Both before and after assembly into finished cable, t
6、he insulation employed on the circuit conductorsshall comply with (a) or (b) and the insulation employed on the control/signal conductors shall comply with(c):a) THHN Construction - Jacketed insulation for a Type NM or NMC cable shall have a nylon orsimilar jacket and shall comply with the thickness
7、 and other applicable requirements for TypeTHHN thermoplastic-insulated wire without (see 6.2.4) any surface marking of THHN, -B,orany ampacity or temperature rating.b) TW Construction - Insulation without a nylon jacket shall comply with the thicknessrequirements for a Type TW thermoplastic-insulat
8、ed wire. The insulation material shall complywith (1) or (2):2) For TYPE NM only - Type NM is eligible to use a thermoplastic insulating materialother than PVC. The performance and ratings of the material as insulation shall bedetermined by investigation and shall be:ii) Mechanically comparable to t
9、he nylon or similarly jacketed PVC insulation of TypeTHHN wire, andiii) In accordance with “Physical properties of insulation of thermoplastic other than PVCfrom Type NM cables” Table in UL 1581.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL
10、(c) Insulated control/signal conductors - The insulation material shall be a dry-locations PVCthat complies with the requirements for Type TFN insulation without any surface marking of thetemperature rating. The tensile strength and elongation shall comply with the “Physicalproperties of PVC insulat
11、ion from Type TFN and TFFN fixture wires Table 50.155 in UL 1581.The deformation test is to be conducted at 121.0 1.0C (249.81.8F) with a decrease of notmore than 50 percent in the thickness of the PVC insulation. The force to be used is 300 gramsfor 18 AWG and 400 grams for 16 AWG conductors.4.6 As
12、sembly4.6.1 General4.6.1.1 At least two but not more than four circuit conductors, and an optional “-PCS” signal/controlsubassembly in accordance with 4.6.1.3 shall be used in a Type NM cable. Two or three circuit conductorsshall be used in a Type NMC cable. In a given cable all of the circuit condu
13、ctors shall be of the same size.4.6.1.2 One grounding conductor shall be used in every cable.4.6.1.3 PCS SubassembliesA round or flat NM cable may employ a -PCS” subassembly consisting of two 18 or 16 AWGsignal/control conductors for use in Class 2 and Class 3 circuits with a thermoplastic jacket ov
14、erthe two 18 or 16 AWG conductors. The thermoplastic jacket shall be a minimum of 30 mils(0.76mm) thick. The thermoplastic jacket shall meet the requirements of 5.2.Exception: A flat NM cable may employ a -PCS” subassembly consisting of two 18 or 16 AWGconductors for use in Class 2 and Class 3 circu
15、its provided with an overall thermoplastic jacketthat is a minimum of 60 mils (1.52mm) thick where the PCS subassembly is attached to thepower conductor subassembly by a web or similar means. The thermoplastic jacket shall meetthe requirements of 5.2.4.6.2 Cabling Methods4.6.2.1 In Type NM cables co
16、ntaining two circuit conductors, the circuit conductors shall either be laidparallel or shall be cabled with a length of lay that is not longer than indicated in Table 2. In Type NMcables containing more than two two or more circuit conductors, the circuit conductors shall be cabled witha length of
17、lay no longer than indicated in Table 2 except that, for sizes 14 - 10 AWG copper or 12 - 10AWG aluminum or copper-clad aluminum, whether or not a binder is employed, the circuit conductorsshall either be cabled with a length of lay which is not specified, shall be bundled together parallel to onean
18、other, or shall be laid parallel. In Type NMC cables, the circuit conductors shall be laid parallel. In around cable, the direction of lay may be changed at intervals throughout the length of the cable. Theintervals need not be uniform. In a cable in which the lay is reversed:a) Each area in which t
19、he lay is right- or left-hand for not less than 5 complete twists (full 360cycles) shall have the insulated conductors cabled with a length of lay that is not greater thanindicated in Table 2, andb) The length of each lay-transition zone (oscillated section) between these areas of right- orleft-hand
20、 lay shall not exceed 1.8 times the maximum length of lay indicated in Table 2.4.6.2.2 A flat NM-PCS cable shall consist of an NM cable where either 1) the NM cable is joined to thePCS subassembly by means of a web or similar method or 2) the power conductors and PCSsubassembly are contained under t
21、he overall jacket. One of the following constructions is acceptable.STANDARD NUMBER: UL 719 -2-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL(a) A flat NM-PCS cable may consist of an NM cable connected in parallel to a “-PCS”subassembly with
22、 an additional jacket of not less than 30 mils over the PCS subassembly asnoted in 4.6.1.3(a) There shall be no reduction in the overall jacket thickness when the PCSportion is separated from the circuit conductor portion.(b) A flat NM-PCS cable may consist of an NM cable in parallel with the PCS su
23、bassembly.4.6.2.3 A round NM-PCS cable shall consist of circuit conductors as described in 4.6.2.1 and a “-PCS”subassembly as described in 4.6.1.3(a) all within the overall NM cable jacket. The overall jacket shall notbe less than 30 mils. The cabling of the circuit conductors and jacketed signal/co
24、ntrol cables shall meetthe requirements in 4.6.2.1.5.6 Vertical flame5.6.1 When tested in accordance with 7.6, a vertical specimen of finished Type NMC cable, of finishedType NM cable, and of the insulated circuit conductors shall not flame longer than 60 seconds followingfive 15 second applications
25、 of the test flame, the period between applications being 15 seconds. For anNM-PCS cable, a vertical specimen of (1) the finished cable, (2) the “-PCS” jacketed assembly, and (3)the individual insulated signal/control conductors shall not flame longer than 60 seconds following five 15second applicat
26、ions of the test flame, the period between applications being 15 seconds. If any specimenshows more than 25 percent of the indicator flag burned away or charred (soot that can be removed witha cloth or the fingers and brown scorching area shall be ignored) after any of the five applications of flame
27、,the wire or cable shall be judged capable of conveying flame along its length. If any specimen emitsflaming or glowing particles or flaming drops at any time that ignite the cotton on the burner, wedge, orfloor of the enclosure (flameless charring of the cotton shall be ignored), the wire or cable
28、shall be judgedcapable of conveying flame to combustible materials in its vicinity.5.14 Crushing resistance test for round cable5.14.1 Finished round Type NM-PCS and NM cable that contains two circuit conductors with an insulatedgrounding conductor, or three or four circuit conductors with an insula
29、ted or bare grounding conductor, inwhich the conductors are twisted, and which does not comply with the separation requirement in 5.18.1and all finished round Type NM cable in which the conductors are parallel, shall be tested for crushingresistance in accordance with the method described in the Cru
30、shing-Resistance Test of Round Type NMCables Section of the Reference Standard for Electrical Wires, Cables, and Flexible Cords, UL 1581. Thecable is not acceptable if the average of the ten crushing trials is less than 1200 lbf or 5338 N or 544 kgffor a test length of round Type NM cable containing
31、 two circuit conductors with an insulated groundingconductor, or three or four 14 or 12 AWG circuit conductors.5.15 Abrasion resistance test of jacket on flat cable5.15.1 The jacket on finished flat cable containing two or three 14 or 12 AWG copper or 12 or 10 AWGaluminum insulated circuit conductor
32、s shall not wear through exposing the underlying protective sheath orconductor assembly in fewer than 70 complete cycles of abrasion against sharp steel edges. On a flatNM-PCS cable, the signal/control conductors shall be seperated from the NM power conductor side andonly the remaining NM cable is s
33、ubjected to this test. The test is to be conducted as described in 7.14.5.16 Pulling-though-joists test5.16.1 Finished, flat, parallel cable containing two or three insulated 14 or 12 AWG copper or 12 AWGaluminum or copper-clad aluminum circuit conductors with a grounding conductor with or without t
34、he“-PCS”; round Type NM with or without the “PCS” suffix cable that contains two circuit conductors with aninsulated grounding conductor, or three or four circuit conductors with a grounding conductor, fillers, orSTANDARD NUMBER: UL 719 -3-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCT
35、ION ORDISTRIBUTION WITHOUT PERMISSION FROM ULboth, in which the conductors are twisted, and which does not comply with the separation requirements in5.18.1; and all finished round Type NM cable with or without the “-PCS” suffix in which the conductors areparallel, shall each be constructed to withst
36、and the low-temperature pulling through joists described in7.15 without any opening occurring in the jacket that exposes the cable interior (see 7.15.6 and 7.15.7),without reduction of the spacing between the circuit conductors in flat cable to a value less than indicatedin Table 3 (see 5.16.2), wit
37、hout any change in the position of the grounding conductor that results in themetal of the grounding conductor touching the insulation on a circuit (see 5.16.2), and without physicaldamage to the insulation (see 5.16.2).6.1.16 If control/signal conductors are present, an NM cable shall carry the suf
38、fix letters “-PCS” todesignate the presence of Class 2 or 3 signal/control conductors.6.1.17 For a round NM-PCS cable, the jacket over the signal/control conductors shall be marked with thefollowing statement: “The conductors under this jacket are only for signal/control connections, not forcircuit
39、power”. Additionally, the overall jacket of a round NM-PCS cable shall be marked to indicate thefollowing: “This cable contains both signal/control and power conductors.” These markings shall repeatevery 24 inches.6.1.18 For a flat NM-PCS cable construction utilizing a separate 60- mil jacketed sign
40、al/control conductorconstruction, the jacket over the signal/control conductors shall be marked with the following statement:“Conductors under this jacket are only for signal/control connections, not for circuit power”. Thesemarkings shall repeat every 24 inches.6.2.11 The marking “There are both si
41、gnal/control circuits and power circuits in this cable. Do not use thesignal/control conductors as circuit power conductors. The signal/control circuits are under jacket markedas such. ” shall be marked on the tag, reel, or carton of cable Type NM-PCS.7.12.2 Edgewise7.12.2.1 The cable is to be crush
42、ed edgewise between two flat, rigid, parallel, horizontal steel plates thatare 2 inches or 50 mm wide. A previously untested sample of finished flat cable is to be used, with tentrials being made. For each trial, the cable - with its axis horizontal and its flat faces vertical - is to begripped at p
43、oints 3 inches or 75 mm to each side of the section of cable to be crushed and manuallytwisted by turning the cable 90 degrees in opposite directions. The flat faces thus remain vertical at themidpoint and the opposite flat faces are up and horizontal. For half of the trials, the samples are to betw
44、isted in a clockwise direction and, for the other half, the samples are to be twisted in the oppositedirection.7.12.2.2 One of the steel plates is to be secured to the underside of the head of a compression machinewhose head travels vertically, and the other is to be secured directly below the first
45、 on the bed of themachine. After being twisted as indicated in 7.12.2.1, the cable is to be placed on the bed plate with thelength of the cable parallel to the 2 inch or 50 mm dimensions of the plate and the vertical flat faces of thecable at the center of the plate. The twist in the cable is to be
46、maintained throughout the test eithermanually or by means of a jig.7.12.2.3 The insulated circuit conductors and the two steel plates are to be connected to low-voltageindicators (buzzers or the like) and to power supplies to provide a means for indicating a short circuitbetween circuit conductors o
47、r between one any circuit conductor and the steel plates. The groundingconductor is to be out of the circuit. The cable, the apparatus, and the surrounding air are to be in thermalequilibrium with one another at a temperature of 23.0 2.0C (73.4 3.6F) during the test. , .STANDARD NUMBER: UL 719 -4-UL
48、 COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL7.12.2.4 The head of the machine is to be started and moved toward the bed at the rate of 0.50 0.05in/min or 10 1 mm/min. The travel is to be continued until contact is established between the insu
49、latedcircuit conductors or between one or more of the insulated circuit conductors and one or both plates. Thecrushing force being exerted by the machine and the points between which the contact occurs are to benoted and recorded, and the downward direction of travel of the head is to be reversed. If the insulatedcircuit conductors do not remain one above the other until a contact is established, or if the cable doesnot remain vertical at the center of the plates, the results of the trial are to be disregarded and a new trialis to be made at a different location.7.12.2
