Copyright 2008 Ted "Smitty" Smith. Left click on the presentation ICON located at the bottom of the...

Left click on the presentation ICON located at the bottom of the slide directory to the left of the this slide.

Each slide will transition to the correct answer automatically in 2:00 minutes. The correct answer will transition in 10 seconds. You may also left click on the slide to manually transition.

Do not worry about writing down the correct answer for now. You will have the opportunity to do that at the end of the two minute drill

Good luck Remember to start the slide show to

activate the timer. Copyright 2005 Ted "Smitty" Smith

This drill is a mixture of calculations and code look up questions. You have seen many of them before. Focus on time. Try to find all the answers before the slide transitions. Remember do not worry about writing down the right answer for now. When you reach the end all of the slides will be repeated without the timer so you can take your time to find the ones you missed and write down the correct answers then. Click on the slide to proceed.


1. Equipment grounding conductors shall be permitted to be sectioned within a listed multiconductor cable, provided the combined _______________ complies with 250.122.

A. Current and loadB. Voltages of all applied loadsC. Circular mill areaD. None of the above


Circular mill area

310.13


A conductor with insulation marked ZW will be suitable for use in all: Wet locations Hospital operating rooms House boats None of the above


Wet locations Table 310.13(A)


Where more than one calculated or ____________ ampacity could apply for a given circuit, the lowest value shall be used. Determined Tabulated Corrected Derated


Tabulated 310.15(A)(2)


Where bare or covered conductors are installed with insulated conductors, the temperature rating of the bare or covered conductor shall be _____________ for the purpose of determining ampacity Equal to the lowest temperature rating of the

insulated conductors Equal to the highest temperature rating of the

insulated conductors Equal to the average temperature ratings of the

insulated conductors. None of the above


Equal to the lowest temperature rating of the insulated conductors

310.15(B)(3)


A 2 AWG TW conductor is installed in a location where the ambient temperature is expected to be 108 degrees F. The temperature correction factor for conductor ampacity in this location is _________. .96 .88 .82 .71


.71 Table 310.16 Bottom, 60c wire at 102

degrees F. I recommend using a straight edge

when using NEC tables. A clear plastic 6 inch ruler is best.


If the ambient temperature is 30 degrees C, the minimum insulation that a conductor must have and still have the capacity to carry current is __________ 60 C 105 C 90 C Any of these


Any of these All of these conductors are rated for 30

degrees C


Determine the minimum sized THHN aluminum conductor that can be installed to feed a load of 104 amperes that is located in a freezer that has an ambient temperature of 22 degrees Celsius. 1 AWG 2 AWG 3 AWG 1/0 AWG


100 A 1/0 AWG 110.14(c) will require you handle 104

amperes in the 75 C column, so another two wire sizes will be required, therefore 1/0.


The ampacity of six-current carrying 10 AWG RHW aluminum conductors in a raceway in an ambient temperature of 75 degrees F is ___________› 30A› 22A› 16A› 12A


15.75A Table 310.16 and 310.15(B)(2)(a)


The ampacity of nine current carrying 10 AWG THW conductors installed in a 20 inch long raceway is _________.

› 25A› 30A› 35A› None of these


35A Bundle factors do not apply to raceways

that are 24 inches in length or less.


Enclosures for switches or over current devices shall not be used as junction boxes, auxiliary gutters, or raceways for conductors feeding through or tapping off to other switches or over current devices, unless adequate space for this purpose is provided. The conductors shall not fill the wiring space at any cross section to more than _______ percent of the cross-sectional area of the space.

› 20› 25› 35› 40


40 312.8


What is the area in square inches for a 14 AWG RHW without outer covering conductor?› 0.0209› 0.0172› 0.0252› 0.0278


0.0209 Table 5, Chapter 9


What is the cross sectional area in square inches for 12 AWG RHH with outer covering conductors?

› 0.0117› 0.0353› 0.0252› 0.0327


A 200A feeder installed in Schedule 80 rigid non-metallic conduit has three 3/0 AWG THHN, one 2 AWG THHN and one 6 AWG THHN conductors. What is the minimum sized raceway required? 2 inch 2.5 inch 3 inch 3.5 inch


2 inch


What size rigid metal nipple is required for three 4/0 AWG THHN, one 1/0 AWG THHN and one 4 AWG THHN conductors? 1.5 inch 2 inch 2.5 inch None of these


1.5 inch 1.239 60% fill based on note 4 to Table 1


What size outlet box is required for one 12/2 NM cable that terminates on a switch, on 12/3 NM cable that terminates on a receptacle, and the box has manufactured internal cable clamps. › 4 x 1 1/4 square› 4 x 1 1/2 square› 4 x 2 1/8 square› None of these


4 x 2 1/8 Square


Machine screw type fasteners that engage not less than two and thread forming machine screws that engage not less than two threads in the enclosure may be used to mount equipment grounding bars, buses and lugs to enclosures.

› True› False


True 250.8


What is the net computed demand load for the air conditioning and heat for a 40 unit multifamily building that has an air conditioner ( 3hp, 3.91 kW 230V) and two baseboard heaters (3 kW) in each unit. › 160 kW› 240 kW› 6 kW› 5 kW


240 kW Heat is larger load than A/C


What is the demand load on the main service entrance of an apartment complex that is supplied with a 120/208V single phase service for twelve 3.25 kW ovens? 10 kW 18 kW 15 kW 20 kW


18 kW


What is the general lighting load for a dwelling unit with 2,700 square feet of living space not including open porches, garages, or unused or unfinished spaces not adaptable for future use?› 8100 VA› 12600 VA› 2700 VA› 6480 VA


8100 VA


What is the feeder or service demand for two 3 kW ranges?› 3 kW› 4.8 kW› 4.5 kW› 3.9 kW


4.5 kW


If the total demand is 30 kW for a 120/240V dwelling unit, what is the minimum sized service and feeder copper conductor size allowed? 4 AWG 3/0 AWG 2 AWG 1/0 AWG


2 AWG 30,000/240= 125A Table 310.15(B)(6) shows 2 AWG

copper for 125A services


What is the demand on the main service entrance of a single family dwelling of a range with a nameplate rating of 13.9 kVA at 240 volts?› 8000 VA› 8800 VA› 9600 VA› 10000 VA


8800 VA Table 220.55 Note 1


The disconnecting means for surge protective devices shall not be considered a disconnecting means when determining the maximum number of handles for the service disconnecting means. True False


True 230.71(A)(2)


Metal enclosures and raceways for service conductors and equipment shall be connected to the _______________ system conductor if the electrical system is grounded or to the ________________ conductor for electrical systems that are not grounded. Grounded/ ungrounded Grounded/ grounding electrode Grounding/ grounded None of the above


Grounded/ Grounding electrode

250.80


Each of the slides will now be repeated.They are not timed in this segment. To change a slide, click on the side with your left mouse button. Be sure to physically look up the answers in your code book to improve your look up speed and skill.
