Spring Test 10 due 05/11/2013

Transcription

1 Spring Test 10 due 05/11/2013 Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. When installed in an agricultural building that houses livestock the wiring material that is not permitted be installed is: 1) type MC cable. 2) hard usage cords when flexibility is necessary. 3) liquidtight flexible nonmetallic conduit. 4) type UF cable. 5) type AC cable. 2. A motor controller is installed in a Class II, Division 1 hazardous location and the enclosure for the controller is rated NEMA 9, dust-ignition-proof. A horizontal run of rigid metal conduit supplies power to the controller from a junction box that contains only conductor splices and the box is designed to prevent the entrance of dust, but does not have a dust-ignition-proof rating. Both the junction box and the controller have threaded hubs, and both are in the Class II, Division 1 area. This installation is permitted provided the horizontal run of conduit between the box and controller is not less than: 1) 18 in. (450 mm). 2) 3 ft (900 mm). 3) 5 ft (1.5 m). 4) 10 ft (3 m). 5) 12 ft (3.7 m). 3. CATV cable from a community antenna system is installed underground to a single-family dwelling. An additional grounding electrode is required to be installed when the grounding electrode conductor connecting the shield of the cable to the electrical system grounding electrode is longer than: 1) 6 ft. (1.8 m). 2) 10 ft. (3 m). 3) 20 ft. (6 m). 4) 25 ft. (7.5 m). 5) 50 ft. (15 m). 4. If Electrical Nonmetallic Tubing is to be used for a whip from a metal box to a fluorescent luminaire in a suspended ceiling, the: 1) space above the ceiling shall be used for environmental air. 2) ceiling shall have a 15-minute finish rating. 3) ceiling shall have a 1-hour finish rating. 4) ENT shall not be installed in lengths greater than 3 ft. 5) circuit rating shall not exceed 15 amperes. 5. A 25 kva transformer is installed on an ungrounded delta 240 volt 3-phase electrical system to supply a 100 ampere 120/240 volt single-phase electrical system, because there is no 120 volt power in the building. The conductor supplying the transformer is size 8 AWG copper protected on the supply end with a 50 ampere circuit breaker. The conductor leading away from the transformer is size 3 AWG copper ending at a single 100 ampere circuit breaker. The maximum distance permitted from the transformer to the 100 ampere circuit breaker is: 1) 10 ft (3 m). 2) 20 ft (6 m). 3) 25 ft (7.5 m). 4) 50 ft (15 m). 5) 75 ft (22.5 m).

2 6. Unless the equipment is marked otherwise, conductors for branch circuits rated 100 or less amperes and using 1 AWG or smaller conductors must be selected from the column of Table (B)(16). 1) 60 C (140 F) 2) 75 C (167 F) 3) 90 C (194 F) 4) any of these 7. The minimum size permitted for copper-clad aluminum conductors is. 1) 14 AWG 2) 12 AWG 3) 10 AWG 4) 8 AWG 8. For an existing dwelling unit, where no additional air-conditioning or electric space-heating equipment will be installed, the first 8 kva of load will be taken at 100% and the remainder of the load will be computed at of the load. 1) 75% 2) 60% 3) 40% 4) 25% 9. A transformer which is intended to be connected to a 3-phase 3-wire ungrounded electrical system for the purpose of creating a 3-phase 4-wire grounded electrical system is called a: 1) boost and buck transformer. 2) insulating transformer. 3) isolation transformer. 4) shielded transformer. 5) zig-zag transformer. 10. Rigid PVC Conduit is run from the metal forming shell of a wet-niche lighting fixture in a permanent swimming pool to the junction box installed in the concrete deck surface. A size 8 AWG copper bonding conductor run in Rigid Nonmetallic Conduit connects the metal forming shell to the surface junction box. The bonding conductor is: 1) required to be solid. 2) permitted to be bare. 3) not permitted to be bare but can be covered rather than insulated. 4) required to be stranded. 5) required to be insulated and permitted to be stranded. 11. A 3-phase transformer is connected for 480 volts on the primary and 208 volts on the secondary. If 200 amperes are flowing on the secondary conductors, the current in the primary conductors will be approximately: 1) 400 amperes. 2) 87 amperes. 3) 200 amperes. 4) 108 amperes. 5) 462 amperes. 12. One commercial building is supplied with 208/120 volt, 4-wire, three-phase power from another building on the same property and under the same management. The feeder is protected in the first building with a 200 ampere circuit breaker, and the conductors are copper Type THWN run underground in Rigid Nonmetallic Conduit. There are three ungrounded conductors, a neutral conductor, and an equipment grounding conductor. At the second building, the neutral and equipment grounding conductors are required to be: 1) kept separated, and the equipment grounding conductor is required to be connected to a grounding electrode.

3 2) bonded together, and not required to be connected to a grounding electrode. 3) kept separated, and grounding either conductor is optional. 4) kept separated, and the neutral is required to be connected to a grounding electrode. 5) connected to a grounding electrode. 13. A three-phase 69 KVA load will be connected to a circuit that is fed from a 3-pole breaker in a 120/240 volt 3Ø, 4-wire panel. This load will draw amps of current through each circuit conductor. 1) ) ) ) ) A multioutlet assembly is a raceway that contains receptacles and is either surface mounted, flush mounted, or free standing such as a power pole, and is permitted to be installed in: 1) concealed locations. 2) outside in damp locations. 3) inside or outside in damp locations. 4) locations subject to severe physical damage when constructed of steel with a minimum thickness of in.. 5) dry locations. 15. A common bonding grid for a permanent swimming pool is formed by connecting together with a bonding conductor all metal parts associated with the pool such as metallic parts of the pool structure, forming shells and mounting brackets of lighting fixtures, metal ladders and other metal fixtures attached to the pool, metal equipment associated with the water circulating system, pool covers and similar metal parts. The conductor used for this bonding is: 1) required to be solid copper not smaller than size 8 AWG. 2) permitted to be solid aluminum if insulated and not smaller than size 8 AWG. 3) required to be insulated copper, stranded, and not smaller than size 8 AWG. 4) permitted to be bare, insulated, or covered copper if not smaller than size 6 AWG. 5) required to be copper not smaller than size 2 AWG. 16. The sheath of nonmetallic cable must extend into a box not less than through a nonmetallic cable knockout opening. 1) 1/8 in. (3.18 mm) 2) 1/2 in. (12.7 mm) 3) 1/4 in. (6 mm) 4) 1/16 in. (1.6 mm) 17. The owner of a "Quick Lube" corporate franchise owns the building and the property it sits on. The owner has expressed a desire to wire the building. Which answer best describes what the owner may do. 1) Cannot wire the building 3) Can wire the building with employees 2) Can wire the building by himself 4) Hire an electrician to help him 18. Neon tubing and conductor must be supported not more than from the electrode connection. 1) 12 in. (300 mm) 2) 6 in. (150 mm) 3) 24 in. (600 mm) 4) none of the above 19. The secondary output conductors of an industrial arc welder consist of an electrode conductor and a workpiece conductor. The workpiece conductor: 1) is considered to be a separately derived system and is to be grounded accordingly. 2) is not required to be grounded to any premises electrical system grounding conductor or grounding electrode. 3) is required to be connected to a ground rod in the area of the welder. 4) shall be grounded to the metal frame of the building in the area of the welder. 5) shall be grounded to the equipment grounding conductor of the supply to the welder. 20. The conductor fill requirements for nonmetallic boxes is determined by:

4 1) Table (A). 2) Table (B). 3) both of the above. 4) none of the above. 21. Of the following, the one not permitted to serve as an equipment grounding conductor for a 30 ampere rated circuit is: 1) Electrical Metallic Tubing. 2) Rigid Metal Conduit. 3) Nonmetallic-Sheathed Cable Type NM-B with a size 10 AWG bare copper wire. 4) Metal Clad Cable Type MC with a size 10 AWG insulated green copper wire. 5) a 3 ft (900 mm) length of Flexible Metal Conduit terminating in fittings listed as suitable for grounding. 22. What percentage of the sum of the ratings can be used for a total of 43 receptacles in marinas and boatyards? 1) 50% 2) 40% 3) 30% 4) none of the above 23. Amusement rides and amusement attractions must not be located under or within horizontally of conductors operating in excess of 600 volts. 1) 15 ft (4.5 m) 2) 10 ft (3.0 m) 3) 5 ft (1.5 m) 4) none of the above 24. If type AC Cable is to be used for exposed wiring above a suspended ceiling in a facility classified as a place of assembly the cable shall: 1) be of the jacketed type. 2) not be smaller than size 12 AWG copper. 3) contain a bare equipment grounding conductor in contact with the metal sheath. 4) have an insulated equipment grounding conductor. 5) have an insulated equipment grounding conductor. 25. A 30 ampere, locking type grounding receptacle outlet is used to supply shore power to a boat at a marina. A disconnecting means shall be readily accessible and located so that the distance from the disconnect to the receptacle it controls is not more then: 1) 6 ft (1.8 m). 2) 10 ft (3 m). 3) 24 in. (600 mm). 4) 30 in. (750 mm). 5) 50 ft (15 m). 26. An overhead feeder conductor supplies single-phase 120/240 volt power to a storage building from an office building at commercial property. If the feeder passes over a driveway used for truck traffic, the minimum clearance of the conductors over the drive is: 1) 10 ft (3 m). 2) 12 ft (3.7 m). 3) 15 ft (4.5 m). 4) 18 ft (5.5 m). 5) 22 ft (6.7 m). 27. What is the demand factor percentage permitted to be used to size service-entrance conductors for 20 recreational vehicle sites? 1) 60%

5 2) 50% 3) 45% 4) none of the above 28. A 5 horsepower, 230 volt, 3-phase, design B, motor has a nameplate full-load current of 14 amperes and a service factor of The branch circuit conductors are copper with 75 C insulation and terminations. The minimum permitted conductor size is: 1) 14 AWG. 2) 12 AWG. 3) 10 AWG. 4) 8 AWG. 5) 6 AWG. 29. Each pedestrian entrance to a commercial building is required to have a receptacle outlet at an accessible location and is: 1) permitted to be supplied by a general use branch circuit. 2) required to be supplied by a 20 ampere branch circuit that supplies no other load. 3) required to be supplied by at least one 15 ampere branch circuit. 4) required to be ground-fault circuit interrupter protected. 5) required to be arc-fault circuit interrupter protected. 30. A stand alone fuel cell system is connected to a premises wiring system. The output of the inverter is 120 volt and is connected to 120/240 volt, 3 wire distribution equipment. This output is allowed to supply. 1) multiwire branch circuits only 3) 120 volt circuits only 2) 240 volt circuits only 4) all of these 31. An 80 gallon (300 L) storage type water heater has a full-load rating of 3500 watts at 240 volts. The minimum rating circuit breaker permitted to supply this water heater is: 1) 15 amperes. 2) 20 amperes. 3) 30 amperes. 4) 40 amperes. 5) 50 amperes. 32. Impedance in an alternating circuit is the result of: 1) resistance. 2) capacitive reactance. 3) inductive reactance. 4) all of the above. 33. A Type SJEO flexible cord is used to replace the damaged power cord on a 240 volt 1Ø appliance. The smallest size permitted is AWG where connected to a branch circuit that is protected by a 40 amp branch circuit breaker. 1) 12 2) 8 3) 10 4) 14 5) none of these 34. A gasoline dispenser at a service station is supplied with 120 volt power from a circuit breaker panelboard where the circuit breaker will act as the disconnecting means for the dispenser. The circuit breaker from the following list permitted to serve as the dispenser disconnect is the: 1) single-pole circuit breaker. 2) single-pole, ground-fault circuit interrupter breaker. 3) single-pole, arc-fault interrupter breaker. 4) two-pole circuit breaker. 5) switched neutral circuit breaker. 35. Electrical equipment and wiring methods on rides or concessions must be provided with where such equipment or wiring is subject to physical damage.

6 1) overcurrent protection 2) mechanical protection 3) double insulation 4) all of the above 36. A 25 kva single-phase transformer is connected 480 volts on the primary and 240 volts on the secondary. The primary full-load current of the transformer is: 1) 104 amperes. 2) 52 amperes. 3) 30 amperes. 4) 65 amperes. 5) 60 amperes. 37. Liquidtight flexible nonmetallic conduit cannot be used: 1) where subject to physical damage. 2) in lengths longer than 6 ft (1.8 m). 3) where the voltage of the contained conductors is in excess of 600 volts. 4) all of the above. 38. Electrical permits are required for 1) branch circuit extensions, security 3) Fire alarm testing, HVAC component cameras and doorbell installation replacement and RV wiring 2) minor label installations, garbage disposal 4) None of the above replacements 39. A particular piece of single-phase, 240 volt portable equipment is connected to a permanent wiring system with extra hard service Type SO copper flexible cord. The minimum conductor ampacity required for the equipment is 16 amperes. The minimum size flexible cord permitted to supply this equipment is: 1) 16 AWG. 2) 14 AWG. 3) 12 AWG. 4) 10 AWG. 5) 8 AWG. 40. Strut-type channel raceway: 1) is only permitted to contain conductors that supply fixtures supported by the raceway. 2) shall not have a conductor fill in excess of 20% of the cross-sectional area of the raceway. 3) is required to be supported at intervals not to exceed 8 ft. 4) shall not be permitted to penetrate partitions or walls. 5) shall not be installed where concealed. 41. Lighting outlets are not required in which dwelling unit? 1) kitchens 2) attics 3) crawl spaces 4) clothes closets 42. The attachment plug and receptacle are permitted to serve as the controller for a portable motor that has a rating not greater than: 1) 1/4 horsepower. 2) 1/3 horsepower. 3) 1/2 horsepower. 4) 3/4 horsepower. 5) 1 horsepower. 43. A standard 15- or 20-ampere, 125 volt receptacle that is used on normal building circuits is permitted to be supplied by a technical power system and installed in an audio equipment room if:

7 1) the room is restricted to use by qualified personnel. 2) the circuits are arc-fault circuit interrupter protected. 3) no other receptacles supplied by the normal power system with a grounded neutral conductor are present in the room. 4) only isolated ground type receptacles are used. 5) all lighting in the room is also supplied by the technical power receptacles. 44. A 37.5 kva, three-phase transformer is connected 480 volts on the primary and 208/120 volts on the secondary. The primary full-load current of the transformer is 45 amperes. The transformer supplies a panelboard, 25 ft (7.5 m) away that has a 100 ampere main circuit breaker. The conductor from the transformer to the panelboard is size 3 AWG copper. The primary of the transformer is protected with a 60 ampere circuit breaker. The minimum size copper conductors with 75 C insulation and terminations permitted to supply the primary of the transformer is: 1) 3 AWG. 2) 4 AWG. 3) 6 AWG. 4) 8 AWG. 5) 10 AWG. 45. If the rating of a branch circuit does not match the standard overcurrent protective device ratings specified in Section 240.6, the next higher standard OCPD rating can be used when. 1) the circuit is rated less than 800 amperes 2) it is not a multi-outlet branch circuit serving cord-and-plug connected loads 3) the circuit operates at less than 347/600 volts 4) both a and b 46. The total load of a room air conditioner supplied by an individual branch circuit shall not exceed percent of the branch-circuit rating. 1) 50 2) 75 3) 80 4) The combined length of FMC, FMT, and LFMC in the same ground path must not exceed: 1) 6 ft (1.8 m). 2) 10 ft (3.0 m). 3) 3 ft (900 mm). 4) all of the above. 48. When connecting conductors to receptacles at inserts in a cellular metal floor raceway, the conductors are: 1) permitted to be cut and connected to the receptacle terminal screws. 2) must be cut and pigtailed to each receptacle. 3) only permitted to be supply one receptacle. 4) not permitted to be installed as loop-wiring. 5) required to be attached to the receptacle terminals without cutting the conductors that feed on to other outlets. 49. Class 1 power-limited circuits are supplied from a source that has a rated output of not more than volts and volt-amperes. 1) 30; ) 600; volts and 1500 volt-amperes 3) 60; 150 4) none of the above 50. A building has underfloor raceway installed to supply power to office desk locations in an open room. If a floor outlet is removed, the conductors that were connected to the receptacle outlet:

8 1) are permitted to be taped and placed back into the underfloor raceway. 2) must be marked as an abandoned cable if left in the raceway. 3) shall have the bare conductor covered with a listed insulating material. 4) shall have the conductors cut and spliced with tape applied to exceed the original insulation value. 5) shall be removed from the raceway. 51. In critical care areas, patient bed receptacles may be: 1) single. 2) duplex. 3) quadruplex. 4) all of the above. 52. Power sources for a Class 2 or a Class 3 circuit shall be a listed. 1) auto transformer 2) control transformer 3) Class 2 or Class 3 transformer 4) none of the above

9 Spring Test 10 due 05/11/2013 Answer Section MULTIPLE CHOICE 1. ANS: (A) 2. ANS: (2) 3. ANS: (A)(4) Ex 4. ANS: (C) & (5) 5. ANS: (B)(3), (C)(6) 6. ANS: 1 7. ANS: 2 Table ANS: (A) 9. ANS: ANS: (B)(2)(b) 11. ANS: A (208 V / 480 V) = ANS: (B)

10 13. ANS: 5 I = [ ] = amps NAT: Obj ABank TOP: 3-ph: Current Calc 14. ANS: (A) 15. ANS: (B) 16. ANS: (C) 17. ANS: 1 OAR ANS: (C) 19. ANS: ANS: (A)(2) 21. ANS: ANS: 1 Table ANS: (B)(2) 24. ANS: (A)

11 25. ANS: (B) 26. ANS: (4) 27. ANS: 3 Table ANS: A 1.25 = 19 A 430.6(A), Table , (A), Table (B)(16) 29. ANS: (A) 30. ANS: Stand-Alone Systems. (C) Single 120-Volt Nominal Supply. The inverter output of a stand-alone fuel cell system shall be permitted to supply 120 volts, nominal, to single-phase, 3-wire 120/240-volt service equipment or distribution panels where there are no 240-volt loads and where there are no multiwire branch circuits. In all installations, the rating of the overcurrent device connected to the output of the fuel cell system(s) shall be less than the rating of the service equipment. This equipment shall be marked as follows: 31. ANS: 2 (3500 W / 240 V) 1.25 = 18.2 A ANS: 4 General knowledge 33. ANS: (A) 34. ANS: (A) NAT: Obj ABank 35. ANS:

12 36. ANS: 2 25 kva 1000 / 480 V = 52 A 37. ANS: ANS: 1 OAR ANS: 2 Table 400.5(A) 40. ANS: (1) 41. ANS: (A) 42. ANS: (B) 43. ANS: (A)(4) 44. ANS: (B) Table (B)(16) 45. ANS: (B) 46. ANS: (B) 47. ANS: (6)(d)

13 48. ANS: ANS: (A) 50. ANS: ANS: (B)(2) 52. ANS: (A)(1),(2), or (3)