Master Examination Practice Drill #1 2011

Master Examination Practice Drill #8 2011(16)1. In commercial and industrial establishments, all 15- and 20- ampere, single-phase, 125 volt receptacles installed in _________ require GFCI protection for personnel.I. BathroomsII. Kitchens

I onlyII onlyNeither I nor IIBoth I and II

QuestionAnswerReference NEC PG. #1.D210.8(B)(1)&(2) 512. Communications wires and cables shall have a voltage rating of NOT less than _____.60 volts120 volts300 volts600 voltsQuestionAnswerReference NEC PG. #2.C800.179 6803. An emergency system is required to have NO more than ______ to have power available in the event of failure of the normal electrical supply system.10 seconds15 seconds45 seconds5 minutesQuestionAnswerReference NEC PG. #3.A700.126244. X-ray equipment installed in a hospital may be served by a hard service cord with a suitable plug provided the branch-circuit rating does NOT exceed _______.15 amperes20 amperes30 amperes50 amperesQuestionAnswerReference NEC PG. #4.C517.71(A), Ex.4555. Conductors supplying more than one (1) motor shall have an ampacity of NOT less than _____ of the full-load current rating of the largest motor in the group and 100% of the full-load current ratings of all the other motors in the group.125 percent110 percent150 percent175 percent QuestionAnswerReference NEC PG. #5.A430.24(1)&(2)3186. Given: A straight pull of size 4 AWG and larger conductors is to be made in a junction box that will have 3 in. conduit and two (2) 2 in. conduits entering on the same side and exiting on the opposite wall. No splices will be contained in the box. Which of the following listed junction boxes is the MINIMUM required for this installation?18 in. x 12 in.20 in. x 18 in.24 in. x 24 in.30 in. x 30 in.

QuestionAnswerReference NEC PG. #6.C314.28(A)(1)1833in. (largest conduit) x 8 = 24 in.7. Given A recreational vehicle campground has one hundred-fifty (150) campsites provided with electrical power. Twenty-five (25) of the campsites are reserved as tent sites. How many of the sites are required to have a 20-ampere, 125-volt receptacle?105125150NoneQuestionAnswerReference NEC PG. #7.C 551.715008. Determine the MAXIMUM overcurrent protection permitted for size 14 AWG THWN copper motor control-circuit conductors tapped from the load side of a motor overcurrent protection device. Given: The conductors require short-circuit protection and do not extend beyond the motor control equipment enclosure.20 amperes25 amperes30 amperes100 amperesQuestionAnswerReference NEC PG. #8.DTbl. 430.72 (B)3279. Where size 6 AWG THWN copper branch-circuit conductors supply a 240-volt, single-phase, 5,000 VA non-motor operated appliance, the MAXIMUM standard size circuit breaker permitted for overcurrent protection on this circuit is rated _______.55 amperes40 amperes35 amperes30 amperes

QuestionAnswerReference NEC PG. #9.C422.11(E)(3)291Single phase current formula 240.6(A)91I = Power I = 5,000 VA = 20.8 amperes x 150% = 31.2 amperes Volts Volts*NOTE The next standard size circuit breaker with a rating of 35 amperes should be selected 10. The ampacity of size 1/0 AWG THWN/THHN, dual-rated copper conductors enclosed in rigid metal conduit (RMC) when installed underground in direct contact with the earth is _______.170 amperes125 amperes130 amperes150 amperes QuestionAnswerReference NEC PG. #10.D300.5(B)137Tbl. 310.104(A)169Tbl. 310.15 (B)(16)11. Every electrified truck parking space intended to provide an electrical supply for transport refrigerated units shall be equipped with a _______.I. 30 ampere, 480-volt, 3-phase, 3-pole, 4-wire receptacleII. 60 ampere, 280-volt, 3-phase, 3-pole, 4-wire receptacle

I onlyII onlyEither I or IIBoth I and IIQuestionAnswerReference NEC PG. #11.C626.31(C(55112. Flexible cord is permitted to be connected to fluorescent luminaires where the cord ___________.Has an ampacity of at least 20 amperesIs visible its entire lengthIs at least a size 12 AWGRuns through holes in wallsQuestionAnswerReference NEC PG. #12.B410.62(C)(1)(2)a.28413. An outdoor motor fuel gasoline dispensing pump is considered to be a Class I, Div. 2 hazardous location up to _____ above grade level within _____ horizontally from any edge of the motor fuel pump enclosure.18 inches 10 feet24 inches 20 feet24 inches 10 feet18 inches 30 feetQuestionAnswerReference NEC PG. #13.ATbl. 514.3(B)(1)42614. Determine the MAXIMUM permitted operational setting of an adjustable inverse time circuit breaker used for branch-circuit, short-circuit and ground-fault protection of a 15 hp, 208-volt, three-phase, squirrel cage, Design B, continuous-duty ac motor. Assume the rating you select will be sufficient for the starting current of the motor and exceptions need not be applied.46.20 amperes80.85 amperes115.5 amperes369.6 amperesQuestionAnswerReference NEC PG. #14.C430.6(A)(1)311Tbl. 430.250338430.52(C)(1)322Tbl. 430.52323FLC of motor 46.2 amperes x 250% = 115.5 amperes15. What is the MAXIMUM distance between supports for straight horizontal runs of trade size 1 in. PVC conduit?10 feet8 feet6 feet5 feetQuestionAnswerReference NEC PG. #15.D Tbl. 352.30 21016. Unless approved for a higher voltage, surface nonmetallic raceways are NOT permitted where the voltage is _______ or more between conductors.120 volts150 volts300 volts277 voltsQuestionAnswerReference NEC PG. #16.C388.12(3)23717. Determine the MAXIMUM size overload protection required for a 480-volt, 3-phase, 15 hp, continuous-duty ac motor, where given the following related information. Assume the value you select will permit the overload device to carry the motor load and modification of this value is not required.Design CTemperature rise 40 CService factor 1.12Nameplate ampere rating 18 amperes

20.7 amperesC. 22.5 amperes18.0 amperesD. 23.4 amperesQuestionAnswerReference NEC PG. #17.A430.6(A)(2)312430.32(A)(1)319FLA = 18 amperes x 115% = 20.7 amperes 18. Any pipe or duct system foreign to the electrical installation must not enter a transformer vault? Which of the following listed is NOT considered foreign to the vault?A roof drainA building water mainAn air duct passing through the vaultAn automatic fire protection water sprinklerQuestionAnswerReference NEC PG. #18. D450.47 35519. Given: A 50 kVA transformer with a 480-volt, 3-phase, primary and a 208Y/120 volt, 3-phase secondary is to be installed. Overcurrent protection is required on both primary and secondary side of the transformer. Determine the MAXIMUM size overcurrent protection device permitted on the primary side.125 amperes150 amperes175 amperes200 amperesQuestionAnswerReference NEC PG. #19.B450.3(B)348Tbl. 450.3(B)349240.6(A(913 phase current formulaI = kVA x 1000 I = 50 x 1000 = 50,000 = 60.2 amperes E x 1.732 480 volts x 1.732 831.36

60.2 amperes x 250% = 150.5 amperes*NOTE A 150 ampere OCP device is required

20. An inverse time circuit breaker used as the disconnecting means for a 50 hp, 480-volt, three-phase continuous-duty, induction-type type ac motor shall have an ampere rating of at LEAST ________.82 amperes75 amperes163 amperes98 amperesQuestionAnswerReference NEC PG. #20.B430.6(A)(1)311Tbl. 430.250338430.110(A)332FLC of motor = 65 amperes x 74.75 amperes 21. Circuit breakers are NOT rated to carry 100 percent of the continuous load continuously, unless they have a rating for at LEAST _________.100 amperes200 amperes400 amperes600 amperesQuestionAnswerReference NEC PG. #21.DTrade Knowledge 22. A fifteen (15) ft. horizontal run of rigid metal conduit (RMC) is to be installed between two enclosures located in a Class II, Division 1 hazardous location. One enclosure is dust ignition proof, the other is not. The NEC requires a MINIMUM of _______ sealing fittings.None requiredOneTwo Three

QuestionAnswerReference NEC PG. #22.A502.15(2)38732. Where fuses are used for motor overload protection, if the supply system is a 3-wire, 3-phase, ac with one conductor grounded, the NEC requires a MINIMUM of how many fuses?None requiredOneTwo ThreeQuestionAnswerReference NEC PG. #23.D430.3632124. Conductors leading to a gasoline motor fuel dispensing pump shall be _________.Provided with a switchRed in colorOrange in colorInsulated with MTW insulationQuestionAnswerReference NEC PG. #24.A514.11(A)42825. In general, direct-buried cables of 13,000 volts must be buried at a depth of NOT less than ______.24 inches30 inches36 inches42 inchesQuestionAnswerReference NEC PG. #25.B Tbl. 300.50, Col. 1146Click here to continue to non-timed drill

1. In commercial and industrial establishments, all 15- and 20- ampere, single-phase, 125 volt receptacles installed in _________ require GFCI protection for personnel.I. BathroomsII. Kitchens

I onlyII onlyNeither I nor IIBoth I and II

QuestionAnswerReference NEC PG. #1.D210.8(B)(1)&(2) 512. Communications wires and cables shall have a voltage rating of NOT less than _____.60 volts120 volts300 volts600 voltsQuestionAnswerReference NEC PG. #2.C800.179 6803. An emergency system is required to have NO more than ______ to have power available in the event of failure of the normal electrical supply system.10 seconds15 seconds45 seconds5 minutesQuestionAnswerReference NEC PG. #3.A700.126244. X-ray equipment installed in a hospital may be served by a hard service cord with a suitable plug provided the branch-circuit rating does NOT exceed _______.15 amperes20 amperes30 amperes50 amperesQuestionAnswerReference NEC PG. #4.C517.71(A), Ex.4555. Conductors supplying more than one (1) motor shall have an ampacity of NOT less than _____ of the full-load current rating of the largest motor in the group and 100% of the full-load current ratings of all the other motors in the group.125 percent110 percent150 percent175 percent QuestionAnswerReference NEC PG. #5.A430.24(1)&(2)3186. Given: A straight pull of size 4 AWG and larger conductors is to be made in a junction box that will have 3 in. conduit and two (2) 2 in. conduits entering on the same side and exiting on the opposite wall. No splices will be contained in the box. Which of the following listed junction boxes is the MINIMUM required for this installation?18 in. x 12 in.20 in. x 18 in.24 in. x 24 in.30 in. x 30 in.

QuestionAnswerReference NEC PG. #6.C314.28(A)(1)1833in. (largest conduit) x 8 = 24 in.7. Given A recreational vehicle campground has one hundred-fifty (150) campsites provided with electrical power. Twenty-five (25) of the campsites are reserved as tent sites. How many of the sites are required to have a 20-ampere, 125-volt receptacle?105125150NoneQuestionAnswerReference NEC PG. #7.C 551.715008. Determine the MAXIMUM overcurrent protection permitted for size 14 AWG THWN copper motor control-circuit conductors tapped from the load side of a motor overcurrent protection device. Given: The conductors require short-circuit protection and do not extend beyond the motor control equipment enclosure.20 amperes25 amperes30 amperes100 amperesQuestionAnswerReference NEC PG. #8.DTbl. 430.72 (B)3279. Where size 6 AWG THWN copper branch-circuit conductors supply a 240-volt, single-phase, 5,000 VA non-motor operated appliance, the MAXIMUM standard size circuit breaker permitted for overcurrent protection on this circuit is rated _______.55 amperes40 amperes35 amperes30 amperes

QuestionAnswerReference NEC PG. #9.C422.11(E)(3)291Single phase current formula 240.6(A)91I = Power I = 5,000 VA = 20.8 amperes x 150% = 31.2 amperes Volts Volts*NOTE The next standard size circuit breaker with a rating of 35 amperes should be selected 10. The ampacity of size 1/0 AWG THWN/THHN, dual-rated copper conductors enclosed in rigid metal conduit (RMC) when installed underground in direct contact with the earth is _______.170 amperes125 amperes130 amperes150 amperes QuestionAnswerReference NEC PG. #10.D300.5(B)137Tbl. 310.104(A)169Tbl. 310.15 (B)(16)11. Every electrified truck parking space intended to provide an electrical supply for transport refrigerated units shall be equipped with a _______.I. 30 ampere, 480-volt, 3-phase, 3-pole, 4-wire receptacleII. 60 ampere, 280-volt, 3-phase, 3-pole, 4-wire receptacle

I onlyII onlyEither I or IIBoth I and IIQuestionAnswerReference NEC PG. #11.C626.31(C(55112. Flexible cord is permitted to be connected to fluorescent luminaires where the cord ___________.Has an ampacity of at least 20 amperesIs visible its entire lengthIs at least a size 12 AWGRuns through holes in wallsQuestionAnswerReference NEC PG. #12.B410.62(C)(1)(2)a.28413. An outdoor motor fuel gasoline dispensing pump is considered to be a Class I, Div. 2 hazardous location up to _____ above grade level within _____ horizontally from any edge of the motor fuel pump enclosure.18 inches 10 feet24 inches 20 feet24 inches 10 feet18 inches 30 feetQuestionAnswerReference NEC PG. #13.ATbl. 514.3(B)(1)42614. Determine the MAXIMUM permitted operational setting of an adjustable inverse time circuit breaker used for branch-circuit, short-circuit and ground-fault protection of a 15 hp, 208-volt, three-phase, squirrel cage, Design B, continuous-duty ac motor. Assume the rating you select will be sufficient for the starting current of the motor and exceptions need not be applied.46.20 amperes80.85 amperes115.5 amperes369.6 amperesQuestionAnswerReference NEC PG. #14.C430.6(A)(1)311Tbl. 430.250338430.52(C)(1)322Tbl. 430.52323FLC of motor 46.2 amperes x 250% = 115.5 amperes15. What is the MAXIMUM distance between supports for straight horizontal runs of trade size 1 in. PVC conduit?10 feet8 feet6 feet5 feetQuestionAnswerReference NEC PG. #15.D Tbl. 352.30 21016. Unless approved for a higher voltage, surface nonmetallic raceways are NOT permitted where the voltage is _______ or more between conductors.120 volts150 volts300 volts277 voltsQuestionAnswerReference NEC PG. #16.C388.12(3)23717. Determine the MAXIMUM size overload protection required for a 480-volt, 3-phase, 15 hp, continuous-duty ac motor, where given the following related information. Assume the value you select will permit the overload device to carry the motor load and modification of this value is not required.Design CTemperature rise 40 CService factor 1.12Nameplate ampere rating 18 amperes

20.7 amperesC. 22.5 amperes18.0 amperesD. 23.4 amperesQuestionAnswerReference NEC PG. #17.A430.6(A)(2)312430.32(A)(1)319FLA = 18 amperes x 115% = 20.7 amperes 18. Any pipe or duct system foreign to the electrical installation must not enter a transformer vault? Which of the following listed is NOT considered foreign to the vault?A roof drainA building water mainAn air duct passing through the vaultAn automatic fire protection water sprinklerQuestionAnswerReference NEC PG. #18. D450.47 35519. Given: A 50 kVA transformer with a 480-volt, 3-phase, primary and a 208Y/120 volt, 3-phase secondary is to be installed. Overcurrent protection is required on both primary and secondary side of the transformer. Determine the MAXIMUM size overcurrent protection device permitted on the primary side.125 amperes150 amperes175 amperes200 amperesQuestionAnswerReference NEC PG. #19.B450.3(B)348Tbl. 450.3(B)349240.6(A(913 phase current formulaI = kVA x 1000 I = 50 x 1000 = 50,000 = 60.2 amperes E x 1.732 480 volts x 1.732 831.36

60.2 amperes x 250% = 150.5 amperes*NOTE A 150 ampere OCP device is required

20. An inverse time circuit breaker used as the disconnecting means for a 50 hp, 480-volt, three-phase continuous-duty, induction-type type ac motor shall have an ampere rating of at LEAST ________.82 amperes75 amperes163 amperes98 amperesQuestionAnswerReference NEC PG. #20.B430.6(A)(1)311Tbl. 430.250338430.110(A)332FLC of motor = 65 amperes x 74.75 amperes 21. Circuit breakers are NOT rated to carry 100 percent of the continuous load continuously, unless they have a rating for at LEAST _________.100 amperes200 amperes400 amperes600 amperesQuestionAnswerReference NEC PG. #21.DTrade Knowledge 22. A fifteen (15) ft. horizontal run of rigid metal conduit (RMC) is to be installed between two enclosures located in a Class II, Division 1 hazardous location. One enclosure is dust ignition proof, the other is not. The NEC requires a MINIMUM of _______ sealing fittings.None requiredOneTwo Three

QuestionAnswerReference NEC PG. #22.A502.15(2)38732. Where fuses are used for motor overload protection, if the supply system is a 3-wire, 3-phase, ac with one conductor grounded, the NEC requires a MINIMUM of how many fuses?None requiredOneTwo ThreeQuestionAnswerReference NEC PG. #23.D430.3632124. Conductors leading to a gasoline motor fuel dispensing pump shall be _________.Provided with a switchRed in colorOrange in colorInsulated with MTW insulationQuestionAnswerReference NEC PG. #24.A514.11(A)42825. In general, direct-buried cables of 13,000 volts must be buried at a depth of NOT less than ______.24 inches30 inches36 inches42 inchesQuestionAnswerReference NEC PG. #25.B Tbl. 300.50, Col. 1146