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
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