©Ted “Smitty” Smith 2008, 2011 THIS DRILL MAY ALSO BE USED IN ACCORDANCE WITH THE 2011 NEC

©Ted “Smitty” Smith 2008, 2011

THIS DRILL MAY ALSO BE USED IN ACCORDANCE WITH THE 2011 NEC.

This speed drill focuses on calculations that will be required for the journeyman and masters examination.

The question slide will still transition in 3 ½ minutes for calculations and 2 mins for code look up questions and will be followed by the correct answer which will stay on the screen for only 10 seconds.

Do not worry about writing down the correct answer during the transition. At the end of the questions, a stop slide will appear and then that will be followed by the questions and answers without the timer so you can review them.

You must click on the screen icon in the lower right hand or left corner of the tool bar to start the slide show in order for the timer to operate.

How many watts is used by a 10 hp motor?

7460 Watts

746 x 10= 7460

What is the ampacity of NM cables installed in a bored hole if the cables are 10-2 with ground and there are a total of three cables installed in the bored hole?

30 amperes

334.80 Must derate based on 90 C column and conductors in a raceway or cable table. There are six current carrying conductors. 10 AWG is 40 amperes and six conductors requires .80 derating. 40X.80= 32

334.80 also states that the adjusted ampacity can not exceed the value found in the 60 C column of 310.16.

60 C column is 30 amperes for #10 AWG copper.

What is the minimum sized equipment grounding conductor required for a circuit that is supplied by a 400A inverse time, overcurrent protective device?

Table 250.122

#3 Copper or #1 Aluminum

A disconnecting means for an emergency system or fire pump shall be installed __________________ from the one to six service disconnecting means for normal service.

Copyright 2005 Ted "Smitty" Smith

• Remote, away from

• 230.72

•

IMC conduit shall be installed so that it is supported in intervals not exceeding ___________ feet?


10 feet

342.30(B)

• What is the maximum branch circuit- short circuit protection allowed for a 208V, three phase, squirrel cage motor with the following nameplate ratings:

• 20 hp, 51.6 A FLC, 1.15 Service Factor, and Design B

• The short circuit protection will be done with an inverse time circuit breaker.

150 ampere inverse time breaker.

• What is the minimum trade name size conduit that can be used for a 310 foot conduit run that will contain nine 10 AWG TW conductors, five 2 AWG RHW conductors with outer covering, and two 6 AWG RHH conductors that do not have an outer covering? The wires will be installed in an intermediate metal conduit.

The total area of the conductors is 1.0934 and a 2” IMC at 31% fill will allow 1.125.

2”

• 1. Standard trade size 2-inch rigid polyvinyl chloride conduit (PVC), shall be supported at least every _____.

a.3 feetb.5 feetc.6 feetd.8 feet

Ted "Smitty" Smith 04/19/23 17

1. b Tbl. 352.30


• 2. When sizing time-delay Class CC fuses for motor branch-circuit, short-circuit, and ground-fault protection, they are to be sized at the same value as _____.

a.inverse-time circuit breakersb.Non-time-delay fusesc.Instantaneous trip circuit breakersd.Adjustable trip circuit breakers


2. b Tbl. 430.52,Note 1


• 3. Where sizes 1/0 AWG single conductor cables are installed in ladder type cable tray, the MAXIMUM allowable rung spacing for the ladder cable tray shall be _____.

a.6 inchesb.9 inchesc.12 inchesd.15 inches


3. b 392.3(B)(1)(a)


• 4. The NEC® requires the MAXIMUM length permitted for a flexible cord supplying a 208-volt, single-phase, room air-conditioner to be ____.



4. b 440.64


• 5. In general, which of the following receptacle outlets in a commercial kitchen are required by the NEC® to be GFCI protected?

a.All 125-volt, single phase, 15- and 20-ampere rated receptacles.

b.All 125-volt, 15- or 20-ampere rated receptacles in wet locations only.

c.All receptacle outlets.d.All 125-volt countertop receptacle outlets

only.Ted "Smitty" Smith 04/19/23 25

5. a 210.8(B)(2)


• 6. All wiring installed in or under an aircraft hanger floor shall comply with the requirements for ______ locations.

a.Class I, Division 1b.Class I, Division 2c.Class II, Division 1d.Class II, Division 2


6. a 513.8(A)


• 7. In general, branch-circuit conductors supplying more than one motor shall have an ampacity of a at least _____ percent of the FLC of the largest motor, and 100 percent of the FLC of the other motor(s) in the group.

a.25b.80c.100d.125


7. d 430.24


• 8. What is the MINIMUM size equipment grounding conductor required for a 5 HP, three-phase, 208-volt motor having 20-ampere rated overload protection and short-circuit overcurrent protection rated at 30 amperes?

a.10 AWGb.14 AWGc.12 AWGd.8 AWG


8. a Tbl. 250.122


• 9. If a circuit breaker serves as the controller for a motor, and the motor is not in sight of the breaker, the NEC® requires which of the following?

a.The motor to be less than 2 HP.b.The breaker be able to be locked in the

open position.c.The motor to be Code letter “E”.d.The breaker to be rated 25,000 AIC.


9. b 430.102(B)(2), Ex.


• 10. In Class II, Division 1, hazardous locations, an approved method of connection of conduit to boxes is _____.

a.Compression fittingsb.Threaded bossesc.Weldingd.All of these


10. b 502.10(A)(4)


• 11. Given: an AC service is supplied with four parallel kcmil aluminum conductors. What is the MINIMUM size copper grounding electrode required, when connected to the concrete-encased building steel used as the grounding electrode system?

a.3/0 AWGb.4/0 AWGc. 250 kcmild.2/0 AWG


11. a Tbl. 250.66500 kcmil X 4 conductors = 2000 kcmil total

*NOTE: Aluminum service-entrance conductors over 1750 kcmil require a size 3/0 AWG copper grounding electrode conductor.


• 12. Given: an AC transformer arc welder has a 50-ampere rated primary current and a 60 percent duty-cycle. Determine the MINIMUM size copper 60°C rated conductors the NEC® requires to supply this welder.



12. b Tbl. 630.11(A) Tbl. 310.16 .78 (duty cycle) X 50 amperes (primary

current) = 39 amperes Tbl. 310.16 requires a size 8 AWG conductor.


• 13. When installing wiring for sensitive electronic equipment, the MAXIMUM voltage to ground is required to be ____ volts.

a.30b.60c.120d.300


13. b 647.1


This is the end of the presentation.

You can now review the slides and answers without the timer.

Click the slide to advance to the next slide

©Ted “Smitty” Smith 2008

This speed drill focuses on calculations that will be required for the journeyman and masters examination.

The question slide will still transition in 3 ½ minutes and will be followed by the correct answer which will stay on the screen for only 10 seconds.

Do not worry about writing down the correct answer during the transition. At the end of the questions, a stop slide will appear and then that will be followed by the questions and answers without the timer so you can review them.

You must click on the screen icon in the lower right hand or left corner of the tool bar to start the slide show in order for the timer to operate.

How many watts is used by a 10 hp motor?

7460 Watts

746 x 10= 7460

What is the ampacity of NM cables installed in a bored hole if the cables are 10-2 with ground and there are a total of three cables installed in the bored hole?

30 amperes

334.80 Must derate based on 90 C column and conductors in a raceway or cable table. There are six current carrying conductors. 10 AWG is 40 amperes and six conductors requires .80 derating. 40X.80= 32

334.80 also states that the adjusted ampacity can not exceed the value found in the 60 C column of 310.16.

60 C column is 30 amperes for #10 AWG copper.

What is the minimum sized equipment grounding conductor required for a circuit that is supplied by a 400A inverse time, overcurrent protective device?

Table 250.122

#3 Copper or #1 Aluminum

A disconnecting means for an emergency system or fire pump shall be installed __________________ from the one to six service disconnecting means for normal service.


• Remote, away from

• 230.72

•

IMC conduit shall be installed so that it is supported in intervals not exceeding ___________ feet?


10 feet

342.30(B)

• What is the maximum branch circuit- short circuit protection allowed for a 208V, three phase, squirrel cage motor with the following nameplate ratings:

• 20 hp, 51.6 A FLC, 1.15 Service Factor, and Design B

• The short circuit protection will be done with an inverse time circuit breaker.

150 ampere inverse time breaker.

• What is the minimum trade name size conduit that can be used for a 310 foot conduit run that will contain nine 10 AWG TW conductors, five 2 AWG RHW conductors with outer covering, and two 6 AWG RHH conductors that do not have an outer covering? The wires will be installed in an intermediate metal conduit.

The total area of the conductors is 1.0934 and a 2” IMC at 31% fill will allow 1.125.

2”

• 1. Standard trade size 2-inch rigid polyvinyl chloride conduit (PVC), shall be supported at least every _____.



1. b Tbl. 352.30


• 2. When sizing time-delay Class CC fuses for motor branch-circuit, short-circuit, and ground-fault protection, they are to be sized at the same value as _____.

a.inverse-time circuit breakersb.Non-time-delay fusesc.Instantaneous trip circuit breakersd.Adjustable trip circuit breakers


2. b Tbl. 430.52,Note 1


• 3. Where sizes 1/0 AWG single conductor cables are installed in ladder type cable tray, the MAXIMUM allowable rung spacing for the ladder cable tray shall be _____.

a.6 inchesb.9 inchesc.12 inchesd.15 inches


3. b 392.3(B)(1)(a)


• 4. The NEC® requires the MAXIMUM length permitted for a flexible cord supplying a 208-volt, single-phase, room air-conditioner to be ____.



4. b 440.64


• 5. In general, which of the following receptacle outlets in a commercial kitchen are required by the NEC® to be GFCI protected?

a.All 125-volt, single phase, 15- and 20-ampere rated receptacles.

b.All 125-volt, 15- or 20-ampere rated receptacles in wet locations only.

c.All receptacle outlets.d.All 125-volt countertop receptacle outlets

only.Ted "Smitty" Smith 04/19/23 68

5. a 210.8(B)(2)


• 6. All wiring installed in or under an aircraft hanger floor shall comply with the requirements for ______ locations.

a.Class I, Division 1b.Class I, Division 2c.Class II, Division 1d.Class II, Division 2


6. a 513.8(A)


• 7. In general, branch-circuit conductors supplying more than one motor shall have an ampacity of a at least _____ percent of the FLC of the largest motor, and 100 percent of the FLC of the other motor(s) in the group.

a.25b.80c.100d.125


7. d 430.24


• 8. What is the MINIMUM size equipment grounding conductor required for a 5 HP, three-phase, 208-volt motor having 20-ampere rated overload protection and short-circuit overcurrent protection rated at 30 amperes?



8. a Tbl. 250.122


• 9. If a circuit breaker serves as the controller for a motor, and the motor is not in sight of the breaker, the NEC® requires which of the following?

a.The motor to be less than 2 HP.b.The breaker be able to be locked in the

open position.c.The motor to be Code letter “E”.d.The breaker to be rated 25,000 AIC.


9. b 430.102(B)(2), Ex.


• 10. In Class II, Division 1, hazardous locations, an approved method of connection of conduit to boxes is _____.

a.Compression fittingsb.Threaded bossesc.Weldingd.All of these


10. b 502.10(A)(4)


• 11. Given: an AC service is supplied with four parallel kcmil aluminum conductors. What is the MINIMUM size copper grounding electrode required, when connected to the concrete-encased building steel used as the grounding electrode system?

a.3/0 AWGb.4/0 AWGc. 250 kcmild.2/0 AWG


11. a Tbl. 250.66500 kcmil X 4 conductors = 2000 kcmil total

*NOTE: Aluminum service-entrance conductors over 1750 kcmil require a size 3/0 AWG copper grounding electrode conductor.


• 12. Given: an AC transformer arc welder has a 50-ampere rated primary current and a 60 percent duty-cycle. Determine the MINIMUM size copper 60°C rated conductors the NEC® requires to supply this welder.



12. b Tbl. 630.11(A) Tbl. 310.16 .78 (duty cycle) X 50 amperes (primary

current) = 39 amperes Tbl. 310.16 requires a size 8 AWG conductor.


• 13. When installing wiring for sensitive electronic equipment, the MAXIMUM voltage to ground is required to be ____ volts.

a.30b.60c.120d.300


13. b 647.1


This is the end of the presentation.

You can now review the slides and answers without the timer.

Click the slide to advance to the next slide

Documents

©Ted “Smitty” Smith 2008, 2011 THIS DRILL MAY ALSO BE USED IN ACCORDANCE WITH THE 2011 NEC