UL SUBJECT 2996-2016 Outline of Investigation for In-Ground Boxes (Issue 1).pdf

1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULOctober 7, 20161UL 2996Outline of Investigation for In-Ground BoxesIssue Number: 1October 7, 2016Summary of TopicsThe is the First Issue of the Outline of Investigation for In-Ground Boxes,UL 299

2、6, for use in accordance with the National Electrical Code,ANSI/NFPA 70. In-Ground Boxes are intended to provide permanent powerin open spaces. The need and desire to utilize commercial outdoor spacefor more than recreation is on the rise in Corporate, Educational andHospitality sectors. Companies a

3、re creating spaces outdoors, allowingemployees to Improve Working Environment, Increase Productivity andStimulate Creativity. Universities regularly hold classes and othereducational events outdoors. Hotels and Conference Centers are adaptingoutdoor spaces to increase revenue by offering Social Even

4、ts andBusiness Meetings. Questions regarding interpretation of requirementsshould be directed to the responsible UL Staff.ULs Outlines of Investigation are copyrighted by UL LLC. Neither a printed norelectronic copy of an Outline of Investigation should be altered in any way. All ofULs Outlines of I

5、nvestigation and all copyrights, ownerships, and rights regardingthose Outlines of Investigation shall remain the sole and exclusive property of ULLLC.COPYRIGHT 2016 UL LLCUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULOCTOBER 7, 2016UL 29962

6、No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTSINTRODUCTION1 Scope .42 Normative References .43 Glossary .54 General Requirements 5CONSTRUCTION5 General 6PERFORMANCE6 Performance Electrical Enclosures 66.1 Volume v

7、erification test .66.2 Dielectric voltage withstand .76.3 Water absorption .76.4 Flammability .86.5 Electrical enclosures of an in-ground box 106.6 Mold stress 126.7 Resistance to crushing 136.8 Resistance to Impact 136.9 Threaded or Unthreaded Holes for Screws in Molded Bosses 147 Performance In-Gr

8、ound Box .157.1 Environmental tests 157.2 Structural load tests on full-size products .167.3 Static friction test .178 Performance In-Ground Box, Electrical Enclosure Assembly 188.1 Resistance to ultraviolet light and water .188.2 Pressure test .188.3 Icing .198.4 Gasket tests 199 Marking .2110 Use

9、and Installation Instructions .22OCTOBER 7, 2016 UL 2996 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULINTRODUCTION1 Scope1.1 This outline of investigation covers in-ground boxes with integral electrical enclosure(s) for housingwiring devic

10、es connected to a branch circuit. The unit is intended to be installed outdoors and in theground. The unit provides access to one or more receptacle outlets and is intended to be installed inaccordance with the National Electrical Code, NFPA 70, the NEC.1.2 This outline does not cover in-ground boxe

11、s for use in hazardous locations as defined in the NationalElectrical Code, NFPA 70.2 Normative References2.1 Products covered by this outline shall comply with the reference installation codes and standard asappropriate for the country where the product is to be used. When the product is intended f

12、or use in morethan one country, the product shall comply with the installation codes and standards for all countrieswhere it is intended to be used.2.2 Where reference is made to any Standard, such reference shall be considered to refer to the latestedition and revisions thereto available at the tim

13、e of printing, unless otherwise specified.2.3 ASTM C1028, Standard Test Method for Determining the Static Coefficient of Friction of Ceramic Tileand Other Like Surfaces by the Horizontal Dynamometer Pull-Meter Method2.4 ASTM D543, Standard Practices for Evaluating the Resistance of Plastics to Chemi

14、cal Reagents2.5 ASTM D570, Standard Test Method for Water Absorption of Plastics2.6 ASTM D635, Standard Test Method for Rate of Burning and/or Extent and Time of Burning Plasticsin a Horizontal Position2.7 ASTM D2444, Standard Test Method for Determination of the Impact Resistance of ThermoplasticPi

15、pe and Fittings by Means of a Tup (Falling Weight)2.8 ASTM G154, Standard Practice for Operating Fluorescent Light Apparatus for UV Exposure ofNonmetallic Materials2.9 US Dept. of Agriculture, Rural Utilities Service, RUS 7 CFR 1755.910, Specification for Outside PlantHousings and Serving Area Inter

16、face SystemsOCTOBER 7, 2016UL 29964UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL3 Glossary3.1 IN-GROUND BOX A vault intended to be buried outdoors which allows access to one or morepower outlets.3.2 ELECTRICAL ENCLOSURE A compartment of an

17、in-ground box relied upon to provide electrical ormechanical protection intended to house electrical connections, splices, wiring devices, etc.Note: the term enclosure used in 6.4.1.2 and Figure 6.1, refer to the three sided test enclosure.4 General Requirements4.1 Except as indicated in 4.2, a comp

18、onent of a product covered by this outline shall comply with therequirement for that component. A component shall comply with the ANCE, CSA, or UL standards asappropriate for the country where the product is to be used.4.2 A component is not required to comply with a specific requirement that:a) Inv

19、olves a feature or characteristic not required in the application of the component in theproduct covered by this outline; orb) Is superseded by a requirement in this outline.4.3 A component shall be used in accordance with its rating established for the intended conditions ofuse.4.4 The values given

20、 in SI (metric) units shall be normative. Any other values given shall be forinformation purposes only.4.5 Each part of an in-ground box shall be so designed and constructed that, when mounted and installedas for normal use, the in-ground box ensures:a) Adequate electrical and mechanical protection

21、to the parts enclosed and minimizes dangerto the user or surroundings;b) Accessible outlets are protected when the box cover is closed; andc) Ground water does not enter in to the wiring space.OCTOBER 7, 2016 UL 2996 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WIT

22、HOUT PERMISSION FROM ULCONSTRUCTION5 General5.1 The electrical enclosure portions of in-ground boxes shall comply with all of the applicableconstruction requirements in the Standard for Nonmetallic Outlet Boxes, Flush-Device Boxes, and Covers,UL 514C.5.2 In-ground boxes shall be designed such that o

23、utlets that are accessible when the enclosure cover isopened are suitably protected from ground water when the cover is closed.5.3 All electrical enclosures and components intended to be submerged while this product is installedshall be rated Type 6 or Type 6P in accordance with the Standard for Enc

24、losures for Electrical Equipment,Environmental Considerations, UL 50E.5.4 An in-ground box shall have a means of securing the cover in the closed position both when in useand when not in use.5.5 Receptacle types 5-15R, 5-20R, 6-15R and 6-20R provided with an in-ground box shall be ratedWeather Resis

25、tance and shall be marked with the phrase Weather Resistant or the abbreviation “WR”that is visible after installation with the in-ground box as intended.5.6 Surfaces exposed after installation of an area greater than 93.5 cm2(14.5 in2) shall be coated with aslip resistant coating and comply with 7.

26、3.Note: Exposed surfaces of an area less than 93.5 cm2(14.5 in2) are exempt from this requirement.PERFORMANCE6 Performance Electrical Enclosures6.1 Volume verification test6.1.1 Electrical enclosures of an in-ground box, their partitioned sections, raised cover, extension cover,or fitting shall hold

27、 a volume of water equal to or greater than the marked volume when tested inaccordance with 6.1.2 6.1.5.6.1.2 All separable cable clamps, associated screws, and fixture/luminaire studs are to be removed. Anyprojections that extend outside the plane of the open face of an electrical enclosure, such a

28、s ears formounting a cover or a flush device, are to be ground flush with the face of the electrical enclosure.6.1.3 All large openings are to be closed by flat, rigid plates sealed in place across the openings. One ofthe plates is to contain two small holes, one for the entrance of a measuring flui

29、d, the other for venting air.6.1.4 Using modeling clay, putty, glazing compound, or similar material:a) A hole through the side or bottom of the sample and a hole between the sample and theplate mentioned in 6.1.3 are to be filled flush with the inside surface.b) An internal hub, if tapped through,

30、is to be filled flush with the end of the hub.c) A bushed opening is to be filled flush with the conduit stop.OCTOBER 7, 2016UL 29966UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL6.1.5 Using a clean, graduated vessel pipette or the equivalen

31、t having a volume equal to or greaterthan the marked volume of the sample and containing water at room temperature, water is to betransferred to the test sample through the hole in the plate mentioned in 6.1.3. The results are acceptableif the test sample holds a volume of water equal to or greater

32、than the marked volume.6.2 Dielectric voltage withstand6.2.1 Any polymeric material used for an electrical enclosure shall withstand for 1 minute withoutbreakdown the application of a 60-hertz, essentially sinusoidal potential of 2500 volts when tested asdescribed in 6.2.2.Exception: An electrical e

33、nclosure made of a polymeric material of the same thickness that has beenpreviously investigated and found to be rated for the application need not be subjected to this test.6.2.2 To determine whether an electrical enclosure complies with the requirement in 6.2.1, three sampleelectrical enclosures o

34、f each thickness are to be tested by applying the test potential across the thinnestsection of the electrical enclosure, excluding knockouts.6.2.3 The two metal electrodes between which the specimens are to be tested individually are each tohave flat faces for contacting the enclosure surfaces. Each

35、 electrode is to be 6.4 mm (0.250 in) wide and108 mm (4.25 in) long with all of its edges square except at the ends, each of which is to be rounded toa cylinder with a radius of approximately 3.2 mm (0.125 in) and with an axis that is perpendicular to thelongitudinal axis of the electrode and parall

36、el to the contact face of the electrode. The dimensions of thecontact face of each electrode are to be 6.4 mm by 101 mm (0.250 in by 4.00 in) to provide a contactarea of 646 mm2(1 in2).6.2.4 Each electrical enclosure is then to be conditioned for 24 hours in moist air having a relativehumidity of 85

37、 5 percent at a temperature of 32 2C (90 4F). Following this conditioning, eachelectrical enclosure is again to be subjected to the specified test potential.6.3 Water absorption6.3.1 Any polymeric material used for an electrical enclosure that is relied upon for electrical ormechanical protection is

38、 to be conditioned as described in 6.3.2. The conditioning shall not result in:a) Any dimensional change of the specimen, including thickness, of more than 3 percent; orb) An increase in the weight of the specimen of more than 3 percent.Exception: An electrical enclosure made of a polymeric material

39、 that has been previously investigatedand found to be acceptable for the application need not be subjected to this test.6.3.2 To determine whether a polymeric material used for an electrical enclosure or part of an electricalenclosure complies with the requirements in 6.3.1, three specimens of the p

40、olymeric material, each being25.4 mm (1 in) by 76.2 mm (3 in) and having a thickness of not more than the minimum thickness of thewall of the electrical enclosure, except a knockout, are to be tested. Each specimen is to be dried in acalcium chloride desiccator for 24 hours. After being dried, each

41、specimen is to be measured, weighedand then immersed for 24 hours in distilled water maintained at a temperature of 23.0 2C (73 4F).Following removal from the water, each sample is to be wiped dry of excess moisture, and the change inthe dimensions and weight are to be determined. The percentage of

42、change is then to be calculated inaccordance with the method for measuring water absorption of plastics in the Standard for PolymericMaterials Short Term Property Evaluations, UL 746A.OCTOBER 7, 2016 UL 2996 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERM

43、ISSION FROM UL6.4 Flammability6.4.1 Materials6.4.1.1 When tested as described in 6.4.1.2 6.4.1.7, a polymeric material used for the electricalenclosure shall not flame for more than 1 minute after the fifth application of a standard test flame.6.4.1.2 The test is to be conducted in a three-sided enc

44、losure that is 305 mm (12 in) wide, 356 mm (14in) deep, and 610 mm (24 in) high. The top and front of the enclosure are to be open. The room or hoodin which the enclosure is located for the test is to be ventilated, but drafts are to be prevented fromaffecting the test flame.6.4.1.3 Each of three 10

45、2-mm2(4-in2) or 114-mm-diameter (4-1/2-in-diameter) specimens of the polymericmaterial in sheet form having a thickness equal to the minimum thickness used for a part or the body ofan electrical enclosure, except a knockout, is to be secured with its vertical axis in the center of theenclosure and w

46、ith both axes parallel to the back of the enclosure. See Figure 6.1.This is generated text for figtxt.OCTOBER 7, 2016UL 29968UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULFigure 6.1Essential dimensions of apparatus and specimenNote - SI unit

47、s for the values specified are:102 mm (4 in); 50.8 mm (2 in); 38.1 mm (1-1/2 in)C Vertical plane parallel to sides of enclosure and containing vertical axis of specimen and longitudinal axis of barrelD Vertical axis of specimen in center of enclosure and parallel to back of enclosureE Plane of the t

48、ip of the barrelF Longitudinal axis of barrelOCTOBER 7, 2016 UL 2996 9UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL6.4.1.4 A Tirrill gas burner to which a gas pilot light is attached shall supply the test flame. The barrel ofthe burner shal

49、l extend 102 mm (4 in) above the air inlets, and its inside diameter shall be 9.5 mm (3/8in). The gas supplied for the flame shall produce 37.63 0.37 MJ/m3(1010 10 Btu/ft3). With the barrelvertical, the overall height of the flame shall be adjusted to 127 mm (5 in). The blue inner cone shall be38.1 mm (1-1/2 in) high. Without disturbing the adjustments for the height of the flame, the valvessupplying gas to the burner and pilot flames shall be closed.6.4.1.5 A wedge to which the base of the burner can be secured is to be provided for tilti