License Examination Practice Drill 2017-6 Ted “Smitty” Smith

Given: A delta-wye, three transformer has a secondary line current of 312.5 amperes at 208V, what is the primary line current at 480V? 135.3 amperes 312.5 amperes 541.25 amperes 416 amperes

1. A 135.3 A

Where a conductor is marked RHW-2 on the insulation what does the -2 represent? The cable has 2 conductors The conductor is double insulated The conductor has a nylon outer jacket The conductor has a maximum operating temperature of 90°C.

2. D Table 310.104(A)

For a grounded electrical system, the equipment grounding conductor shall be sized in accordance with ___________? The undergrounded circuit conductors The overcurrent protective device The service entrance conductors The grounding electrode

3. B 250.32(B)(1) Table 250.122

Determine the allowable ampacity of a size 300 kcmil, THW aluminum conductor installed in a raceway with four (4) other current-carrying conductors when the expected ambient temperature is 44 deg. C. 151 amperes 164 amperes 210 amperes 146 amperes

4. A Tbl. 310.15(B)(16) Tbl. 310.15(B)(2)(a) Tbl. 310.15(B)(3)(a)

Determine the MAXIMUM number of 120-volt, general-purpose duplex receptacles the NEC® permits to be protected by a 20-ampere, 120-volt single-pole circuit breaker in a commercial building. 18 15 13 10

5. C 120 volts x 20 amperes= 2400 VA 2400 VA / 180 VA= 13 receptacles

For lighting systems operating at 30 volts AC or less, the output circuits of the power supply are to be rated for NOT more than ___________? 15 amperes 20 amperes 25 amperes 30 amperes

6. C 411.3

Where there are tenant spaces in a retail shopping mall, each occupant shall have access to the main disconnecting means, EXCEPT: Where the service and maintenance are provided by the building management. Where there are more than six disconnecting means provided. Where the primary feeder transformer does not exceed 600 volts. Where the secondary of the service transformer does not exceed 240 volts to ground.

7. A 240.24(B)(1)(1)

What is the minimum sized bond jumper that can be used to bond the metal fittings of a hydromassage bathtub to the electrical equipment that is not part of the hydromassge bathtub that are located within five feet of the tub? 4 AWG 6 AWG 8 AWG 10 AWG

8. C 680.74 A and B

In general, the grounded conductor and the equipment grounding conductor must be bonded together in _____________? I. Panelboards used as service equipment All sub-panels I only II only Both I and II Neither I not II

9. A 250.24(A) 250.24(A)(5) 408.3(C)

Using the standard method of calculation, what is the demand, in kW, on the undergrounded service-entrance conductors of an apartment complex that has thirty-five (35) electric ranges rated at 11.5 kW each? 403 kW 15 kW 280 kW 50 kW

10. D Tbl 220.55, Col. C

A grounding ring consisting of a size 2 AWG bare copper wire encircling a building, buried 36 in. deep, in direct contact with the earth, is required to have a MINIMUM length of ____________ if it is to be used at a grounding electrode? 15 feet 20 feet 25 feet 50 feet

11. B 250.52(A)(4)

Where applying the optional method of calculation for one-family dwelling, what is the demand load for the heating and cooling, in kW, on the ungrounded service-entrance conductors for a residence that has the following? Three, separately controlled base board heaters rated at 2.8 kW each. One electric thermal storage hearing unit at 22 kW. One air-conditioning unit rated 6.5 kW 32.75 kW 22.00 kW 17.03 kW 26.20 kW

12. B 220.82(C) and (C)(6) Note: Use the larger of the A/C or heating load

Apply the general method of calculation for dwelling units and determine the Minimum demand load, in VA, where a one-family residence has the following fastened in place appliances. Microwave oven – 1,250 VA Trash compacter – 960VA Dishwasher – 1,400 VA Garage door opener – 960 VA 3,428 VA 3,656 VA C. 4,570 4,883 VA

13. A 220.53 Microwave Oven: 1250 VA Trash Compactor: 960 VA Dish Washer: 1400 VA Garage Door Opener: 900 Va Total: 4570 VA x .75= 3428 VA

Where a service riser is installed in a wet location and contains THWN insulated conductors, the wiring method used ________________. Is permitted to be Type AC cable Shall be rigid metal conduit (RMC) Is permitted to be electrical metallic tubing (EMT) Shall be liquidtight flexible metal conduit (LFMC)

14. C 230.43(5)

What is the MAXIMUM distance between supports for straight horizontal runs of trade size 1 ½ in. threaded rigid metal conduit (RMC)? 10 feet 12 feet 14 feet 16 feet

15. C Tbl 344.30(B)(2)

If a 2”, Schedule 80 PVC ,is installed outdoors for a length of 50 feet and the expected temperature range change in the area will be 50 degrees F, then an expansion joint will need be installed in the installation. True or False True False

16. A Table 352.44 and Article 352.44

A thermal barrier shall be required if the space between the resistors and reactors, of 600 volts or less, and combustible material is Less than __________________? 12 inches 18 inches 10 inches 6 inches

17. A 470.3

In theaters, all switches for controlling the emergency lighting systems shall be located __________. On the stage In the lobby In the manger’s office In the project booth

18. B 700.21

Where a 90 ampere, 1000-volt DC load is located 225 feet from the source and is supplied with size 3 AWG copper conductors, determine the approximate voltage drop on the conductors. (K=12.9) 6 volts 4 volts 8 volts 10 volts

19. D VD= 2KDI/CM 2x12.9x225x90/52620= 9.92

A one-family residence is served with insulated 120/240 volt service-drop, supported with a grounded messenger wire from the utility company. This service-drop crosses the swimming pool; the pool has a diving board that is 9 feet above the water level. The NEC® requires the conductors to be a Minimum height of ______ above the pool water level. 25 feet 14 ¼ feet 22 ½ feet 23 ½ feet

20. D Fig. 680.8 Tbl. 680.8 The diving board is 9 feet above the water level. You need 22.5 min. from the water. But that would only make it 13.5 feet above the diving board and you need 14.5 from the diving board. So you will need to be 23.5 feet min, from the water level.

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Given: A delta-wye, three transformer has a secondary line current of 312.5 amperes at 208V, what is the primary line current at 480V? 135.3 amperes 312.5 amperes 541.25 amperes 416 amperes

1. A 135.3 A

Where a conductor is marked RHW-2 on the insulation what does the -2 represent? The cable has 2 conductors The conductor is double insulated The conductor has a nylon outer jacket The conductor has a maximum operating temperature of 90°C.

2. D Table 310.104(A)

For a grounded electrical system, the equipment grounding conductor shall be sized in accordance with ___________? The undergrounded circuit conductors The overcurrent protective device The service entrance conductors The grounding electrode

3. B 250.32(B)(1) Table 250.122

Determine the allowable ampacity of a size 300 kcmil, THW aluminum conductor installed in a raceway with four (4) other current-carrying conductors when the expected ambient temperature is 44 deg. C. 151 amperes 164 amperes 210 amperes 146 amperes

4. A Tbl. 310.15(B)(16) Tbl. 310.15(B)(2)(a) Tbl. 310.15(B)(3)(a)

Determine the MAXIMUM number of 120-volt, general-purpose duplex receptacles the NEC® permits to be protected by a 20-ampere, 120-volt single-pole circuit breaker in a commercial building. 18 15 13 10

5. C 120 volts x 20 amperes= 2400 VA 2400 VA / 180 VA= 13 receptacles

For lighting systems operating at 30 volts AC or less, the output circuits of the power supply are to be rated for NOT more than ___________? 15 amperes 20 amperes 25 amperes 30 amperes

6. C 411.3

Where there are tenant spaces in a retail shopping mall, each occupant shall have access to the main disconnecting means, EXCEPT: Where the service and maintenance are provided by the building management. Where there are more than six disconnecting means provided. Where the primary feeder transformer does not exceed 600 volts. Where the secondary of the service transformer does not exceed 240 volts to ground.

7. A 240.24(B)(1)(1)

What is the minimum sized bond jumper that can be used to bond the metal fittings of a hydromassage bathtub to the electrical equipment that is not part of the hydromassge bathtub that are located within five feet of the tub? 4 AWG 6 AWG 8 AWG 10 AWG

8. C 680.74 A and B

In general, the grounded conductor and the equipment grounding conductor must be bonded together in _____________? I. Panelboards used as service equipment All sub-panels I only II only Both I and II Neither I not II

9. A 250.24(A) 250.24(A)(5) 408.3(C)

Using the standard method of calculation, what is the demand, in kW, on the undergrounded service-entrance conductors of an apartment complex that has thirty-five (35) electric ranges rated at 11.5 kW each? 403 kW 15 kW 280 kW 50 kW

10. D Tbl 220.55, Col. C

A grounding ring consisting of a size 2 AWG bare copper wire encircling a building, buried 36 in. deep, in direct contact with the earth, is required to have a MINIMUM length of ____________ if it is to be used at a grounding electrode? 15 feet 20 feet 25 feet 50 feet

11. B 250.52(A)(4)

Where applying the optional method of calculation for one-family dwelling, what is the demand load for the heating and cooling, in kW, on the ungrounded service-entrance conductors for a residence that has the following? Three, separately controlled base board heaters rated at 2.8 kW each. One electric thermal storage hearing unit at 22 kW. One air-conditioning unit rated 6.5 kW 32.75 kW 22.00 kW 17.03 kW 26.20 kW

12. B 220.82(C) and (C)(6) Note: Use the larger of the A/C or heating load

Apply the general method of calculation for dwelling units and determine the Minimum demand load, in VA, where a one-family residence has the following fastened in place appliances. Microwave oven – 1,250 VA Trash compacter – 960VA Dishwasher – 1,400 VA Garage door opener – 960 VA 3,428 VA 3,656 VA C. 4,570 4,883 VA

13. A 220.53 Microwave Oven: 1250 VA Trash Compactor: 960 VA Dish Washer: 1400 VA Garage Door Opener: 900 Va Total: 4570 VA x .75= 3428 VA

Where a service riser is installed in a wet location and contains THWN insulated conductors, the wiring method used ________________. Is permitted to be Type AC cable Shall be rigid metal conduit (RMC) Is permitted to be electrical metallic tubing (EMT) Shall be liquidtight flexible metal conduit (LFMC)

14. C 230.43(5)

What is the MAXIMUM distance between supports for straight horizontal runs of trade size 1 ½ in. threaded rigid metal conduit (RMC)? 10 feet 12 feet 14 feet 16 feet

15. C Tbl 344.30(B)(2)

If a 2”, Schedule 80 PVC ,is installed outdoors for a length of 50 feet and the expected temperature range change in the area will be 50 degrees F, then an expansion joint will need be installed in the installation. True or False True False

16. A Table 352.44 and Article 352.44

A thermal barrier shall be required if the space between the resistors and reactors, of 600 volts or less, and combustible material is Less than __________________? 12 inches 18 inches 10 inches 6 inches

17. A 470.3

In theaters, all switches for controlling the emergency lighting systems shall be located __________. On the stage In the lobby In the manger’s office In the project booth

18. B 700.21

Where a 90 ampere, 1000-volt DC load is located 225 feet from the source and is supplied with size 3 AWG copper conductors, determine the approximate voltage drop on the conductors. (K=12.9) 6 volts 4 volts 8 volts 10 volts

19. D VD= 2KDI/CM 2x12.9x225x90/52620= 9.92

A one-family residence is served with insulated 120/240 volt service-drop, supported with a grounded messenger wire from the utility company. This service-drop crosses the swimming pool; the pool has a diving board that is 9 feet above the water level. The NEC® requires the conductors to be a Minimum height of ______ above the pool water level. 25 feet 14 ¼ feet 22 ½ feet 23 ½ feet

20. D Fig. 680.8 Tbl. 680.8 The diving board is 9 feet above the water level. You need 22.5 min. from the water. But that would only make it 13.5 feet above the diving board and you need 14.5 from the diving board. So you will need to be 23.5 feet min, from the water level.