necgeneral certification exam (国家电工规程常规认证考试试题).doc

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1、NEC 2008 General Certification Exam(Recent Test Questions)国家电气规程2008版普通认证考试（最近测试题目）1, The width of the working space in front of the electrical equipment shall be the width of the equipment or 30 inches, whichever is greater.电气设备前面的工作空间宽度应为该设备的宽度或30英寸，取其较大值。2，Working space for equipment operating at

2、 600 volts, nominal, or less to ground and likely to require examination, adjustment, servicing, or maintenance while energized shall comply with 110. 26 (A) (1), (A) (2), and (A) (3) or as required or permitted elsewhere in this Code.额定对地操作电压等于或少于600伏的设备的工作空间，很可能需要检测、调试、维修或保养而通电一段时间应遵从条例110。26的A1，A

3、2和A3的要求或符合该条例的其他许可.3, The depth of the working space that has a nominal voltage to ground of 277 volts and the exposed live parts on both sides of the working space shall have a minimum clear distance of 4 feet.名义上对地额定电压277伏的设备的工作深度和其裸露的带电部份其两侧的工作空间必须有不小于4英尺的安全间距。4，In tunnel Installations over 600 v

4、olts the electrical controls for the ventilation system shall be arranged so that the airflow can be reversed.在隧道内安装超过600伏的通风系统，其电气控制必须是预置为气流可逆转的工作方式。（即可逆向运行方向）5, Enclosures for use in tunnels over 600 volts shall be dripproof, weatherproof, or submersible as required by the environmental conditions

5、.用于隧道内的电压超过600伏的设备的外壳应达到不透水、防水和沉入水中的使用环境要求。6， In vaults, all voltages, where there is a manhole opening for personnel, it shall be free of protrusions that could injure personnel or prevent ready egress.在地下室内，所有涉及电的人员检修开口，必须没有突出部份，它会对人员造成伤害及妨碍人员迅速外出。7, For equipment rated 1200 amperes or more and ov

6、er 6 feet wide that contains over current devices, there shall be one entrance to and egress from the required working space not less than 24 inches wide and 6-1/2 feet high at each end of the working space.额定或超过1200安培和包含过流装置超过6英尺宽的设备， 要求其工作空间每端有一个不小于24英寸宽和6-1/2英尺高的入口和出口。8， Manhole openings shall be

7、 free of protrusions that could injure personnel or prevent ready egress.维修孔开口应无突出部份，因它能令人员受伤并妨碍人员迅速外出。9， Manhole and other electrical enclosures intended for personnel entry and specifically fabricated for this purpose shall be of sufficient size to provide safe work space about electrical equipmen

8、t with live parts that is likely to require examination, adjustment, servicing, or maintenance while energized.用来作为人员入口用途的并特别组装的检修孔和其它电气柜壳，对于电气设备和带电部份应提供足够尺寸的安全工作空间，它很可能要求对设备进行检测、调整、维修或保养而通电一段时间。10， The continuity of a grounded conductor shall not depend on a connection to a metallic enclosure, race

9、way, or cable armor.完整的接地导体不应依赖连接的金属外壳，电缆管道或电缆铠装。11，A 15 or 20 ampere branch circuit shall be permitted to supply lighting units or other utilization equipment, or a combination of both. The exception for a dwelling unit shall require small appliance branch circuits be supplied as specified.一个15安培或2

10、0安培的分支电路应允许供照明单元或其它用电设备，或两者结合使用，住宅单元的特例要求规定小家电的供电分支电路。12， In dwelling units, hallways of 10 feet or more in length shall have at least one receptacle outlet.在住宅单位，长度10英尺或更长的走廊最少要有一个电源插座。13， The lighting unit load calculation for a warehouse shall not be less than 1/4 volt amperes per square foot.仓库的

11、照明单位负荷计算应每平方英尺不小于1/4伏安。14, Where there are two to six disconnects as permitted in 225.33 they shall be grouped, and marked to indicate load served.规程225。33允许两个到六个的断路开关应分组和标明负载。15，When there are additional service disconnecting means for fire pumps, as permitted in 230.2, it shall be installed remote

12、 from the one to six service disconnecting Means for normal service to minimize the possibility of simultaneous interruption of supply. 在230.2规定，当消防泵切断装置额外维修时，应安装一到六个远程分段供电切断装置，使正常供电电源同时中断的可能性最少化。16, A unit load of not less than 2 volt amperes per square foot for hospitals shall constitute the minim

13、um lighting load.构成医院单位照明的最低照明负载每平方英尺最低不小于2伏安。17, In each dwelling unit, the load shall be calculated at 1500 volt amperes for each 2 wire small appliance branch circuit. 在住宅单元内，每个2线的小家电分支电路负荷应以1500伏安来计算。18，In an existing dwelling unit where additional air conditioning equipment or electric space he

14、ating equipment is not to be installed，the first 8 KVA of the load at 100 percent, and the remainder of the load at 40 percent shall be used for existing and additional new loads.在现有的住宅单元内，新增的空调设备或空间电热取暖设备的装机容量不需全额计算，首个8KVA负载100%列入，和余下负荷的40%容量列入新增负载。19, Where there is more than one building on the s

15、ame property and under single management, and there are two to six disconnects, that are permitted per Article 225, they shall be grouped. Each disconnect shall be marked to indicate the load served.同一管理部门超过一幢相同性质的建筑物，并有2到6个切断装置，按照规程225条规定，它们应进行分组，每个切断装置应标记显示供电负载。20， When a disconnect for a fire pum

16、p is installed it shall be remote from the one to six normal service disconnecting means for normal service.当安装消防泵断路开关时，为正常供电应安装1到6个远程分段常规供电切断装置。21, Single-phase (other than 2 wire) and multiphase (other than delta-delta, 3 wire) transformer secondary conductors shall not be considered to be protect

17、ed by the primary over current protective device.单相（2线除外）和多相（角接3线除外）的次级导体不应被视为主要的过流保护装置。22，The use of fuses and inverse time circuit breakers with standard and nonstandard ampere ratings shall be permitted.标准和非标准额定值电流应允许使用保险丝和逆时断路器。23， Where an ac system operating at less than 1000 volts is grounded

18、 at any point, the grounded conductor(s) shall be run to each service disconnecting means and shall be run to each disconnecting means grounding conductor(s) terminal or bus.任何一个操作电压低于1000伏的交流系统的任于一个接地点，该点接地导线应延伸连接到每一个供电断路装置并连接到每个断路装置的接地导体的末端或总线。24， Where more than one separately derived system is i

19、nstalled, it shall be permissible to connect a tap from each separately derived system to a common grounding electrode. All tap connections to the common grounding electrode conductor shall be made at an accessible location by : a. A listed connector。 b. The exothermic welding process。 c. Listed con

20、nections to aluminum or copper busbars not less than 1/4 inch * 2 inches. 超过一个分离派生系统的安装，应允许每一个分离派生系统的抽头连接到到常规接地电极的接地电极。所有的接线抽头连接到常规接地电极导体应处于一个易于接近的地点：a, 一个在用的接地导体抽头，b, 放热焊接加工的，c, 在用的铝或铜母线排不得小于四分之一英寸*2英寸。25, Where a grounded conductor is installed and the system bonding jumper connection is not locat

21、ed at the source of the separately derived system， the grounded conductor shall be routed with the derived phase conductors.分离派生系统的接地线的安装和系统连结跳线不是位于该电源处，该接地导线应经延伸到派生出的相（接地线）导线连接。26， The frame of a vehicle shall not be required to be connected to a grounding electrode as defined in 250.52 for a syste

22、m supplied by a generator located on this vehicle under the following conditions:A. The frame of the generator is bonded to the vehicle frame.B. The generator supplies only equipment located on the vehicle or cord and plug connected equipment through receptacles mounted on the vehicle.C. The normall

23、y non-current-carrying metal parts of equipment and the equipment grounding conductor terminals of the receptacles are connected to the generator frame.根据规程250.52明确规定，在下列条件下，车载发电机供电系统的车辆框架不要求连接到接地电极：A，发电机的基座连结在车辆框架上。B，发电机供电的唯一设备位于车辆上或电线和插头连线连接设备通过插座连接在车辆上。C， 设备的常规非载流金属部分和插座的设备接地导线的末端连接到发电机的基座上。27， A

24、 single electrode consisting of a rod, that does not have a resistance to ground of 25 ohms or less shall be augmented by one additional electrode. Where multiple rod, electrodes are installed to meet the requirements they shall not be not less than 6 feet apart.一个单一电极组成的接地端，对地电阻没有或少于25欧姆，应增加一个额外的电极

25、。多电极接地棒的安装距离要符合不能少于6英尺的要求。28, The size of the grounding electrode conductor at the service of a grounded ac system, where the largest ungrounded service entrance conductor is 600 kcmil is 3/0 aluminum or copper-clad aluminum.交流供电接地系统的接地电极导线尺寸，最大600kcmil 的不接地供电进线的（接地电极导线）是3/0 号铝线或镀铜铝线。29，Where the gr

26、ounding electrode conductor is connected to a plate electrode, that portion of the conductor that is the sole connection to the grounding electrode shall not be required to be larger than 6AWG copper or 4AWG aluminum.接地极导线连接到板状接电极时，而该部份导线是唯一连接到该电极的接地线时，则该接地导线不被要求大于6号铜线或4号铝线。30，The minimum size coppe

27、r equipment grounding conductor for a 100 amp over current device for a circuit supplying an individual piece of equipment is 8 AWG.作为单个设备的100安培的供电电路的过流保护装置最小尺寸的铜质设备接地导线应为8号铜线。31, Where the dc system source is located on the premises, a grounding connection shall be made at one of the following:A. T

28、he source.B. The first system disconnection means or over current device.C. By other means that accomplish equivalent system protection and that utilize equipment listed and identified for the use.在直流系统电源的定位前提，地线连接接线条件应在下列条件这一：A， 电源。B，一次回路的断路开关或过流保护装置。C，通过其它途径，利用设备（安装）清单（目录）并确认可使用的装置实现等效系统保护。32, Whe

29、re connected to a pipe electrode, that portion of the grounding electrode conductor, for a 3 wire direct current system, that is the sole connection to the grounding electrode shall not be required to be larger than 6AWG copper wire or 4AWG aluminum wire.三线直流系统中单独连接到管式接地电极的接地导线，该部分接地导线不被要求大于6号铜线或4号铝

30、线。33，Surge Arrestor Selection shall comply with :A. The rating shall be equal to or greater than the maximum continuous operating voltage of the phase-to-ground voltage of a Solidly Grounded System.B. The rating shall be equal to or greater than the maximum continuous operating voltage of the phase-

31、to-phase voltage of an Impedance or Ungrounded System.C. The rating of Silicon Carbide Type Surge Arrestor shall be not less than 125percent of the maximum continuous operating voltage available at the point of application.避雷器的选择应符合下面几点：A，额定值应等于或大于永久性接地系统的相对地电压的最大持续工作电压。B，额定值应等于或大于阻抗或不接地系统的相间最大持续工作电

32、压的额定值。C，碳化硅型的避雷器的额定值应不小于125%最大持续工作电压应得到确定。34， The grounding conductor of a surge arrestor protecting a transformer that supplies a secondary distribution system shall be interconnected by:A. Metallic interconnections.B. Through Spark Gap or Device.C. By Special permission.一个受避雷器保护的变压器二闪配电系统的接地导体应由下列

33、方式互相连通：A，金属互连。B, 通过火花间隙或设备互连。C， 通过特殊的许可途径实现互连。35, Type 1 SPNs （surge protective device): A, shall be permitted to be connected to the supply side of the service disconnect.B, when installed at services the grounding conductor shall be connected to one of the following:1. Grounded service conductor .

34、2. Grounding electrode conductor .3. Grounding electrode for the service.4. Equipment grounding terminal in the service equipment.C, shall be permitted be connected as a type 2 SPDs.1 型浪涌保护装置：A. 应允许连接到供电侧的紧急断电开关。B. 安装到供电系统的接地导线应连接到下列之一：1，已接地的供电系统接地导线。2，接地电极的导线。3，供电系统的接地电极。4，供电设备上的设备接地端子。 C, 应允许和2型浪涌

35、保护装置一样连接。36， In a separately derived system a type 2 SPDs shall be connected on the : load side of the first over current device.在一个分离派生系统中，2型浪涌保护器应连接到负荷侧的第一级过流保护装置。37，A ground ring encircling a building or structure, in direct contact with the earth, consisting of at least 20 feet of bare copper co

36、nductor not smaller than 2 AWG。一个环绕大厦或建筑物的环型接地网，直接与大地连接,由最少20英尺的不小于2号线的祼铜线组成。38， When a ground ring is used as a grounding electrode it shall be buried at a depth below the earths surface of not less than 30 inches.接地环作为一个电极使用时，应深埋于不小于30英寸的地表之下。39， Where used at a point on a circuit, a surge arresto

37、r shall be connected to each ungrounded conductor.在电路上任一点上使用的避雷器，应连接到每一个非接地导体上。40， An insulated grounded conductor of 6 AWG or smaller shall be identified by continuous white or gray outer finish or by three continuous white stripes on other than green insulation along its entire length.一个6号或小于6号绝缘接

38、地导线应由一条完整的白色的或灰色的表面涂层或除了绿色绝缘条纹外整个长度的三条完整的白色条纹来识别。41，Conductors for branch circuits as defined in Article 100, sized to prevent voltage drop exceeding 3 percent at the farthest outlet of power, heating, and lighting loads, or combinations of such loads, and where the maximum total voltage drop on bot

39、h feeders and branch circuits to the farthest outlet does not exceed 5 percent.导线在分支电路上的使用在规程100条明确界定，导线的尺寸大小以防止最远的插座输出电压压降超出3%来确定，电热设备或照明负荷或由这两种组成的负荷，这两者的馈线和分支电路到最远的插座总压降不超过5%。42, Metal or nonmetallic raceways, cable armors, and cable sheath shall be continuous between cabinets,boxes and fittings,

40、other enclosures or outlets.在机柜，盒子和管件其它设备外壳或插座之间的金属或非金属电缆管道，电缆防具和电缆护套铠装均应实现不间断连接。43, Copper-clad Aluminum conductors, 2/0 AWG through 4/0, in vertical raceways, shall be supported if the vertical rise exceeds 180 feet.从2/0到4/0 镀铜铝线，在垂直的电缆管道中敷设时，若垂直升高超过180英尺，应固定支撑。44，No conductor shall be used in suc

41、h a manner that its operating temperature exceeds that designated for the type of insulated conductor involved.没有哪一种导线会在其工作温度超过该型号绝缘导线的指定值的工作环境中使用方式。45, Where conductors or cables are installed in conduits exposed to direct sunlight on or above rooftops, from 1/2 inch to 3-1/2 inches, 22 degrees cen

42、tigrade shall be added to the outdoor temperature to determine the applicable ambient temperature for application of the correction factors in Table 310.16 and Table 310.18.电缆或电线的安装管道暴露在阳光下或在屋顶上时，从1/2英寸到3-1/2英寸，应室外温度应加上22摄氏度来确定其工作温度，其应用校正系数在310。16和310.18。46, In damp or wet location, surface-type enc

43、losures shall be placed or equipped so as to prevent moisture or water from entering and accumulating within the cabinet or cutout box, and shall be mounted so there is at least 1/4 inch airspace between the enclosure and the wall or other supporting surface.在湿度大和潮湿的地方，明装类型的机箱应被配置或装备阻止水份或水进入并累积在机箱内或

44、断路器箱内，并应在箱体和墙体或其它支撑面预留至少1/4英寸空间。47，Noncombustible surfaces that are broken or incomplete shall be repaired so there will be no gaps or open spaces greater than 1/8 inch at the edge of the cabinet or cutout box employing a flush type cover.机箱或断路器箱的嵌入式面板边缘的不燃性表面如果破损或不完整应予以维修使它没有缺口或开口不大于1/8英寸。48, Type

45、TC cables with metallic shielding shall have a minimum bending radius of not less than 12 times the cable overall diameter.TC型金属屏蔽电缆的最小弯曲半径应不小于该型电缆的12倍直径。49, Type LFMC(liquidtight Flexible Metal Conduit) shall be securely fastened in place by an approved means within 12 inches of each box, cabinet,

46、conduit body, or other conduit termination and shall be supported and secured at intervals not to exceed 4 feet 6 inches.液密金属软管应采用安全可靠的方法牢固地固定到每个盒子、机箱及管体的12英寸之内或其它管道末端，且其支撑和保护间隔不超过4英尺6英寸。50, The use of a multioutlet assembly shall be permitted in dry locations.多插座组合应在干燥场所才能使用。51， Cable trays shall n

47、ot have sharp edges, burrs, projections, that could damage the insulation or jackets of the wiring.电缆桥架不能有锋利的边缘，毛刺，突出物，这些都会损坏其绝缘和护套。52, Multiconductor control cables installed in ladder or ventilated trough cable tray, having a usable inside depth of 6 inches or less, the sum of the cross-sectional

48、area of all cables at any cross section shall not exceed 50 percent of the interior cross-sectional area of the cable tray.多芯控制电缆安装在内部深度6英寸或少于6英寸的梯形或通风电缆槽内，所有的电缆的横截面积不得超过电缆槽内部横截面积的50%。53，Where oversized, concentric or eccentric knockouts are not encountered, Type RTRC(reinforced thermosetting resin conduit) shall be permitted to be unsupported where the raceway is not more than 18 inches and remains unbroken lengths (without coupling). Such raceways shall terminate in an outlet box, device box, cabinet, or other termination at each end of the raceway.过大尺寸的，同轴的或偏心的都未遇过，完整无接驳的不超过18英寸长度的增强型