Journeyman Electrician Exam Prep: Practice Questions and Answers, Exams of Electrical Engineering

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Journeyman Electrician Practice Test 2024 Exams

ac Conductors with marked on the insulation are NOT approved for use in a wet location. - CORRECT ANSWER-THHN conductors with THHN insulation are approved for use in dry and damp locations only and conductors with THWN, THHW, and THW insulation are recognized for use in dry and wet locations. Given: A one-family dwelling unit with a demand load of 200 amperes is supplied with a 120/240 volt, single-phase, electrical system from the local utility company. What is the MINIMUM size aluminum THW conductors required for use as service-entrance conductors for this residence? - CORRECT. ANSWER-4/0 AWG one-family dwelling 126/246 volt, single-phase, servi: ntrance conductors to be sized at an ampacity of not less than 83% of the service rating. Therefore, 200 amperes x 83% = 166 amperes: size 4/0 AWG THW aluminum conductors with an allowable ampacity of 180 amperes should be selected for this dwelling. Where a 150 kVA, single-phase transformer having a sccondary vollage of 120/240 is installed at a multi-family dwelling, the fill-load current rating, in amperes, of the secondary is a CORRECT ANSWER-625 amperes To find the full-load current raling of the single-phase transformer apply the single-phase current formula as shown: = (150 kVA x 1000) / 240 valts = 15,000/240 = 625 amperes Which one of the following Listed circuit breakers is NOT a standard ampere rating? - CORRECT ANSWER-75 amperes A SS SS SS I ! the standard ampere ratings for fuses and circuit breakers. A circuit breaker with an ampere I rating of 75 amperes Is not a standard ampere rating. The MINIMUM length of free conductor to be left at each junction box for the purpose of splicing conductors, or making connections to illuminares or devices shall be __ . CORRECT ANSWER inches I free conductor is to be left at each junction box for splices or the connection of luminaires or devices. The intent of this rule is to ensure enough conductor slack for the terminal connections or splices to be made easily. I In general. overhead service-drop conductors shall NOT be smaller than _____. - CORRECT: ANSWER-8 AWG copper overhead serviee-drop conductors lo be not smaller than 8 AWG copper or 6 AWG aluminum or copper-clad aluminum. Do not get service-drop conductors, the overhead conductors between the utility electric supply system and the service point, confused with the service-entrance conductors, the conductors from the service point from the utility company to the service disconnecting means. When a galvanized eve-bolt is to be used as the point of attachment for an electrical service, the NEC requires the eyc-boll. lo be installed NOT less than _____ above [inished grado. - CORRECT ANSWER-10 ft. provide adequate vertical clearance of the conductors and prevent physical damage to the conductors and prevent persons from making accidental contact with the conductors which may create a shock hazard or electrocution. In no case shall the point of attachment of the service- drop conductors to be less than 10 ft. above finished grade. the special provisions for room air conditioners which are (1) rated not over 230-volts ac, single- d. In order to prevent overloading the I scod 50% of the rating of a branch circuit where lighting units, general-use receptacles or appliances are also I phase and (2) which are cord-and-attachment plug conne branch cirenit, as per Section 40.62(C), the tolal rating of the A/C unit shall not ¢ supplied. What shall not be located over the stops of a stairway? - CORRECT ANSWER-overeurrent. devic “overcurrent devices shall not be located over steps of a stairway." This requirement address a I serious safety issue. No one should be required to stand on different treads on a stairway to I replace, repair, maintain, install, troubleshoot, or reset overcurrent devices in a panelboard or | switchboard located in a stairway. Where a permanently installed outdoor swimming pool is located on residential or commercial propertics, al least one (1) single-phase, 125-volt, 15- or 20-amperc receptacle shall be located H not less than. from and not more than____ from the inside wall of the swimming pool. - H H CORRECT ANSWER-G feet - 20 feet H apply to the installation of wiring methods and equipment in or adjacent Lo permanently I installed swimming pools. I each permanently installed swimming pool is to be provided with at least one (1) single-phase, 15- or 20-ampere, 123-volt, receptacle placed not closer than six (6) feet from the pool and not more than twenty (20) feet from the pool. This requirement allows ordinary appliances such as a radio, to be safely plugged in and used . Be advised the I near the pool, but avoids the need for extension cords in the pool vicinity receptacles must be provided with I Metal water pipes installed in or attached to a building or structure shall be bonded to a. the service equipment enclosure b. the grounded conductor at the service c. the grounding electrode conductor d. any of the above - CORR R-Any of the above requires metal water piping systems to be bonded to any of (1) the service entrance enclosure, (2) I the grounded conductor at the service, (3) the grounding electrode conductor. Whore mechanical ! and electrical connections are within equipment, a failure of electrical insulation can result in the connected piping systems becoming energized. For example, an insulation failure in an electrical circuit of a water heater could energize the metal water piping. Metal walor piping systems must be bonded so that when a fault occurs between an ungrounded (hot) conductor and the piping, the potential difference between the two is minimized, thereby reducing the risk of electrical shock.Also, note where installed in or attached to a building or structure, all metal ms, including gas piping, that is likely to become € ‘ized shall be bonded toa piping sy grounded soures. I When armored cable, Type AC, is installed in an accessible attic and is run parallel Lo the sides of rafters, studs, or floor joists, I a. the cable shall be protected with running boards b. the cable shall be protected by guard strips al least as high as the cable c. either A or B indicates open, single-conductors such as Type USE-2 and single-conductor cable listed and identified as PV wire are permitted foruse in PV source circuits within the PV array. These conductors are evaluated and listed for use where exposed to sunlight and wet conditions. For dwelling units, GFCI protection is required for all single-phase, 125-volt, 15- and 20-ampere receptacles installed within six (6) feet of the top inside edge of the bowl of sinks located in I a. laundry rooms I ! I b. bathrooms I ! c. garages ! I —— ! I d. all of these areas - CORRECT ANSWER-AIl of these arcas I I ! no matler whal. the location or room ina dwelling, where the 13- or 20-ampere, 123-volt eceptacles are installed within six (6) feet from the top inside edge of the bowl of the sink, GFCI I protection must be provided to prevent a ground-fault shock hazard. For a building or structure where the meter enclosure is adjacent to the service disconnecting I means, il is permitted Lo ground the meter enclosure to the conductor on the load side of ! the service dis f ground-fault protection is not provided. - CORRECT ANSWER- H Grounded H The meter enclosure to be grounded by connection on the load side of the service disconnect I ; oo. oy. I I where (1) no ground-fault protection is installed, (2) the meter enclosure is adjacent to the I I service disconnecting means, and (3) the grounded service conductor is nol smaller than the size H I specified H Ina dwelling unit where a 123-volt, 15- or 20-ampere receptacle is located under the counter for an in-sink waste disposer, the receptacle must be provided with a. AFCI protection only b. GEC] protection only c. both AFCI and GFCI protection. I d. neither AFC] nor GFCT protection - CORRECT ANSWER-Both AFCI and GFCI protection I Because of the presence of water and grounded surfaces that contributes to a potential shock I hazard any 123-volt, 15- or 20-ampere receptacle installed within six (6) feet of a sink is required to be I GFCI protceled. Section 210.12U\) verifies AFC] protection is required Lor all 120-volt, 15- or I I 20-ampere branch-circuits that supply outlets in kitchens in dwellings. AFCI devices are I designed to determine resistance to unwanted tripping due to the presence of arcing that occurs in utilizalion cquipmont under normal operating condilions or to a loading condition that closely mimics an arcing fault. Where a 123-volt, 15-ampere receptacle is connected to a 120-valt branch circuit supplying two (2) or more receptacles or outlets, the maximum permitted cord-and-plug-connected load to the I receptacle is .- CORRE! ER-12 amperes the general rules regarding branch circuits. Branch circuit and receptacle ratings are addressed in Part II of Article 210. To prevent overlicating receptacles, a receptacle shall not supply a Lolal I cord-and-plig-connecled load in excess of lhe maximum specified in Table 21(BX2), where H connected to a branch circuit supplying multiple receptables or other outlets. This table shows a H | 15-ampere rated receptacle may carry a maximum cord-and-plug-connected load of 12 amperes | I under this condition. I a continuous load is a load expected to continue for three (3) hours or more. The installation I requirements for fixed outdoor electric deicing and snow melting equipment, fixed outdoor electric deicing and snow melting equipment shall be considered a continuous load. When sizing conductors and overcurrent protection for the fixed outdoor equipment you must take into consideration the equipment can operate over 3 hours, so it is considered a continuous load. In regard to a commercial building, where a service-entrance conduit having a length of six (6) feet contains four (4) size 2 AWG THWN insulated copper current-carrying conductors, each of the conductors have an allowable ampacily of CORRECT ANSWER-92 ampercrs To solve this problom first locate the conductor size,and look under the copper THWN column I with a temperature rating of 75° C and note the ampacity of the conductors is 115 amperes. The table is based on an ambient temperature of 86° C and not more than 3 current-carrying I conductors in the raceway. I | . oe . . . o in this situation there are 4 current-carrying conductors in the raceway therefore, we must apply H the correct adinstment factor (derating value) 2 AWG THWNW ampacily = 115 amperes (belore derating)115 ampercs x 80% (adjustment [actor) = I $2 amperes I What material should not be used for Grounding electrodes. - CORRECT. ANSWER-Aluminum For a 300 ampere electrical circuit, what is the minimum size copper equipment grounding conductor as por NEC?- CORRECT ANSWER awg 4 AWG is the minimum size wire for a 300 ampere circuit ac What is the minimum size secondary conductor required for a 2 wire 480 valts/ 120 volts transformer rated at 2.3 KVA with 750C temperature at terminals? - CORRECT ANSWER-14 AWG Secondary transformer current = 2300 / 120 = 19.16 amperes The suitable conductor is 14 AWG with 20 amperes capacity at 750C What is the resistance of the conductor if the conductor voltage drop is 3.6 volts and current ANSWER-O.2 ohms flowing through conductor is 18 amperes? - C Conductor voltage drop = 3.6 volts IR=3.6 valis R=3.6/18=0.2 ohms When an electrical circuit tested with ohmmeter, a short circuit is indicated by a reading of cvusatusttenn - CORRECT. ANSWER-Zoro For slalionary small motors rated loss than oes the branch cireuit over current device may serve as a controller. - © What is the demand factor applied in calculating feeder or service conductor load for a commercial kitchen having four e Demand factor for kitchen cquipmont in other than dwelling unil. shall be applied according to 220.56 table. A SS SS SS Ina metal wire-ways, the distance between supports shall not exceed ...0...0... ft. - CORRECT. ANSWER-10 Underground wiring shall be installed in which of the following conduit a.) Threaded rigid metal b.) Threaded steal intermediate metal ¢.)All options are correct T ANSWER-180 ohms For Copper it is NO.10for aluminum it is NO 8 All 15,20 amperes receptacle outlets installed in bathrooms of dwelling units shall always If the panel board rating is 100 amperes, what shall be the over current device rating located in panel board? - CORRECT. The over current device raling musi nol be grealor than panel board rating in which it is located A SS SS SS ac replace a fixed wiring of a structure What is the minimum percentage rated voltage that a storage battery should supply the rgency load? - CORRECT ANSWER-87 1/2 % er The vertically run motal wire-ways shall be surely supported at intervals not oxcending ..... CORRECT ANSWER- ft of wire way and shall nol have more than one joint belwecn supports. 15 Classl, Division1 Should ungrounded ducts or conduits should be sealed before entering buildings? - CORRECT. A continuous load is load where the maximum current is expected to continue for... hours or more. - CORRECT ANSWER-3 A SS SS SS ac