Transcript Master Examination Practice Drill #1 2011

Master Examination
Practice Drill #5 2011
Ted “Smitty” Smith
O Given: a 150 kVA service transformer has a
480Y/277 volt, 3-phase secondary. What is
the approximate full-load ampere rating of
the primary of the transformer?
180 amperes
B. 312 amperes
C. 542 amperes
D. 416 amperes
A.
O 1. A
O 180.32 A
O Where a conductor is marked RHW-2 on the
insulation what does the -2 represent?
A. The cable has 2 conductors
B. The conductor is double insulated
C. The conductor has a nylon outer jacket
D. The conductor has a maximum
operating temperature of 90°C.
O 2. D Table 310.104(A)
O For a grounded electrical system, the
equipment grounding conductor shall be
sized in accordance with ___________?
A. The undergrounded circuit conductors
B. The overcurrent protective device
C. The service entrance conductors
D. The grounding electrode
O 3. B
O 250.32(B)(1)
O Table 250.122
O Determine the allowable ampacity of a size
kcmil THW aluminum conductor installed in
a raceway with four (4) other currentcarrying conductors when the expected
ambient temperature is 44 deg. C.
A. 151 amperes
B. 164 amperes
C. 210 amperes
D. 146 amperes
O 4. B
O Tbl. 310.15(B)(16)
O Tbl. 310.15(B)(2)(a)
O Tbl. 310.15(B)(3)(a)
O Determine the MAXIMUM number of 120-
volt, general-purpose duplex receptacles the
NEC® permits to be protected by a 20ampere, 120-volt single-pole circuit breaker
in a commercial building.
A. 18
B. 15
C. 13
D. 10
O 5. C
O 120 volts x 20 amperes= 2400 VA
O 2400 VA / 180 VA= 13 receptacles
O For4 lighting systems operating at 30 volts
or less, the output circuits of the power
supply are to be rated for NOT more than
___________?
A. 15 amperes
B. 20 amperes
C. 25 amperes
D. 30 amperes
O 6. C
O 411.2
O Where there are tenant spaces in a retail
shopping mall, each occupant shall have
access to the main disconnecting means,
EXCEPT:
A. Where the service and maintenance are
provided by the building management.
B. Where there are more than six
disconnecting means provided.
C. Where the primary feeder transformer
does not exceed 600 volts.
D. Where the secondary of the service
transformer does not exceed 240 volts
to ground.
O 7. A
O 240.24(B)(1)(1)
O Determine the conductor allowable ampacity
given the following related information:
 Ambient temperature of 44°C
 250 kcmil THWN copper conductors
 Four (4) current-carrying conductors in
the raceway
 Length of raceway is 50 feet.
A. 160 amperes
B. 167 amperes
C. 200 amperes
D. 209 amperes
O 8. B
O Tble. 310.15(B)(16)
O Tbl. 310.15(B)(2)(a)
O Tbl. 310.15(B)(3)(a)
O 250 kcmil THWN copper ampacity 255 A
O 255 A x .82 temp correction x .8 adj factor
O In general, the grounded conductor and the
grounding conductor must be bonded
together in _____________?
 I. Panelboards used as service equipment
 All sub-panels
A. I only
B. II only
C. Both I and II
D. Neither I not II
O 9. A
O 250.24(A)
O 250.24(A)(5)
O 408.3(C)
O 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?
A. 403 kW
B. 15 kW
C. 280 kW
D. 50 kW
O 10. D
O Tbl 220.55, Col. C
O 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 ____________?
A. 15 feet
B. 20 feet
C. 25 feet
D. 50 feet
O 11. B
O 250.52(A)(4)
O
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?
 One blower motor rated 1.2 kW, interlocked with both space
heating and AC equipment.
 One central electric space-heating unit rated 25 kW
 One air-conditioning unit rated 6.5 kW
A.
B.
C.
D.
32.75 kW
25.00 kW
17.03 kW
26.20 kW
O 12. C
O 220.82(C) and (C)(4)
O Note: Use the large of the A/C or heating
load
O 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
A. 3,428 VA
B. 3,656 VA
C. C. 4,570
D. 4,883 VA
O 13. A
O
O
O
O
O
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
O Where a service riser is installed in a wet
location and contains THWN insulated
conductors, the wiring method used
________________.
A. Is permitted to be Type AC cable
B. Shall be rigid metal conduit (RMC)
C. Is permitted to be electrical metallic
tubing (EMT)
D. Shall be liquidtight flexible metal
conduit (LFMC)
O 14. C
230.43(5)
O What is the MAXIMUM distance between
supports for straight horizontal runs of trade
size 1 ½ in. threaded rigid metal conduit
(RMC)?
A. 10 feet
B. 12 feet
C. 14 feet
D. 16 feet
O 15. C
O Tbl 344.30(B)(2)
O At least one receptacle outlet shall be
installed directly above a show window of a
department store for each __________
linear feet of show window area.
A. Six
B. Eight
C. Ten
D. Twelve
O 16. D
O 210.62
O 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 __________________?
A. 12 inches
B. 18 inches
C. 10 inches
D. 6 inches
O 17. A
O 470.3
O In movie theaters, all switches for controlling
the emergency lighting systems shall be
located __________.
A. On the stage
B. In the lobby
C. In the manger’s office
D. In the project booth
O 18. B
O 700.21
O Where a 90 ampere, 240-volt, single-phase
load is located 225 feet from a panelboard
and is supplied with size 3 AWG copper
conductors, determine the approximate
voltage drop on the conductors. (K=12.9)
A. 6 volts
B. 4 volts
C. 8 volts
D. 10 volts
O 19. D
O VD= 2KDI/CM
O 2x12.9x225x90/52620= 9.92
O A one-family residence is served with
insulated 120/240 colt service-drop
conductors, 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 5
feet above the water level. The NEC®
requires the conductors to be a Minimum
height of ______ above the pool water level.
A. 25 feet
B. 14 ¼ feet
C. 22 ½ feet
D. 19 ½ feet
O 20. C
O Fig. 580.8
O Tbl. 680.8
O Given: A trade size 2 in. electrical metallic
tubing (EMT) containing four (4) size 2/0
AWG THWN copper conductors is to be
installed in a pull box for a straight pull of
the conductors. What is the MINIMUM
required length of the pull box?
A. 4 inches
B. 12 inches
C. 16 inches
D. 24 inches
O 21. C
O 314.28
O 2x8= 16
O In a commercial garage work area, which of
the following receptacles, if any, are required
to have GFCI protection?
 I. 15 ampere general-purpose
receptacles for hand tools and portable
lights.
 II. 20 ampere receptacles serving
electrical diagnostic equipment only.
A. I only
B. II only
C. Both I and II
D. Neither I and II
O 22. C
O 210.8(B)(8)
O 511.12
O Conductors tapped from a feeder and
supplying the primary of a transformer need
not have overcurrent protection, if the length
of the tap conductors are not over 25 feet
and have an ampacity of at LEAST ______ of
the rating of the overcurrent device
protecting the feeder conductors.
A. One-third
B. One-half
C. 80 percent
D. 75 percent
O 23. A
O 240.21(B)(3)(1)
O Where conductors carrying alternating
current are installed in ferrous metal
raceways, ________.
All phase conductors, the grounded
conductor and equipment grounding
conductors shall be grouped together
B. The phase conductors shall not be grouped
with the grounded conductor
C. The equipment grounding conductor is not
permitted to be in the same raceway with
the grounded and ungrounded conductors
D. The equipment grounding conductors are
not permitted to be installed in a common
raceway with the grounded conductors.
A.
O 24. A
O 300.20(A)
O When connecting utilization equipment to a
20-ampere rated branch-circuit that also
serves luminaires (lighting fixtures), the
utilization equipment shall have an ampere
rating of NOT more than _______.
10 amperes
B. 15 amperes
C. 16 amperes
D. 12 amperes
A.
O 25. A
O 210.23(A)(2)
O 20A x 50%= 10 A
Click Here to Proceed without
the timer
O Given: a 150 kVA service transformer has a
480Y/277 volt, 3-phase secondary. What is
the approximate full-load ampere rating of
the primary of the transformer?
180 amperes
B. 312 amperes
C. 542 amperes
D. 416 amperes
A.
O 1. A
O 180.32 A
O Where a conductor is marked RHW-2 on the
insulation what does the -2 represent?
A. The cable has 2 conductors
B. The conductor is double insulated
C. The conductor has a nylon outer jacket
D. The conductor has a maximum
operating temperature of 90°C.
O 2. D Table 310.104(A)
O For a grounded electrical system, the
equipment grounding conductor shall be
sized in accordance with ___________?
A. The undergrounded circuit conductors
B. The overcurrent protective device
C. The service entrance conductors
D. The grounding electrode
O 3. B
O 250.32(B)(1)
O Table 250.122
O Determine the allowable ampacity of a size
kcmil THW aluminum conductor installed in
a raceway with four (4) other currentcarrying conductors when the expected
ambient temperature is 44 deg. C.
A. 151 amperes
B. 164 amperes
C. 210 amperes
D. 146 amperes
O 4. B
O Tbl. 310.15(B)(16)
O Tbl. 310.15(B)(2)(a)
O Tbl. 310.15(B)(3)(a)
O Determine the MAXIMUM number of 120-
volt, general-purpose duplex receptacles the
NEC® permits to be protected by a 20ampere, 120-volt single-pole circuit breaker
in a commercial building.
A. 18
B. 15
C. 13
D. 10
O 5. C
O 120 volts x 20 amperes= 2400 VA
O 2400 VA / 180 VA= 13 receptacles
O For4 lighting systems operating at 30 volts
or less, the output circuits of the power
supply are to be rated for NOT more than
___________?
A. 15 amperes
B. 20 amperes
C. 25 amperes
D. 30 amperes
O 6. C
O 411.2
O Where there are tenant spaces in a retail
shopping mall, each occupant shall have
access to the main disconnecting means,
EXCEPT:
A. Where the service and maintenance are
provided by the building management.
B. Where there are more than six
disconnecting means provided.
C. Where the primary feeder transformer
does not exceed 600 volts.
D. Where the secondary of the service
transformer does not exceed 240 volts
to ground.
O 7. A
O 240.24(B)(1)(1)
O Determine the conductor allowable ampacity
given the following related information:
 Ambient temperature of 44°C
 250 kcmil THWN copper conductors
 Four (4) current-carrying conductors in
the raceway
 Length of raceway is 50 feet.
A. 160 amperes
B. 167 amperes
C. 200 amperes
D. 209 amperes
O 8. B
O Tble. 310.15(B)(16)
O Tbl. 310.15(B)(2)(a)
O Tbl. 310.15(B)(3)(a)
O 250 kcmil THWN copper ampacity 255 A
O 255 A x .82 temp correction x .8 adj factor
O In general, the grounded conductor and the
grounding conductor must be bonded
together in _____________?
 I. Panelboards used as service equipment
 All sub-panels
A. I only
B. II only
C. Both I and II
D. Neither I not II
O 9. A
O 250.24(A)
O 250.24(A)(5)
O 408.3(C)
O 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?
A. 403 kW
B. 15 kW
C. 280 kW
D. 50 kW
O 10. D
O Tbl 220.55, Col. C
O 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 ____________?
A. 15 feet
B. 20 feet
C. 25 feet
D. 50 feet
O 11. B
O 250.52(A)(4)
O
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?
 One blower motor rated 1.2 kW, interlocked with both space
heating and AC equipment.
 One central electric space-heating unit rated 25 kW
 One air-conditioning unit rated 6.5 kW
A.
B.
C.
D.
32.75 kW
25.00 kW
17.03 kW
26.20 kW
O 12. C
O 220.82(C) and (C)(4)
O Note: Use the large of the A/C or heating
load
O 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
A. 3,428 VA
B. 3,656 VA
C. C. 4,570
D. 4,883 VA
O 13. A
O
O
O
O
O
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
O Where a service riser is installed in a wet
location and contains THWN insulated
conductors, the wiring method used
________________.
A. Is permitted to be Type AC cable
B. Shall be rigid metal conduit (RMC)
C. Is permitted to be electrical metallic
tubing (EMT)
D. Shall be liquidtight flexible metal
conduit (LFMC)
O 14. C
230.43(5)
O What is the MAXIMUM distance between
supports for straight horizontal runs of trade
size 1 ½ in. threaded rigid metal conduit
(RMC)?
A. 10 feet
B. 12 feet
C. 14 feet
D. 16 feet
O 15. C
O Tbl 344.30(B)(2)
O At least one receptacle outlet shall be
installed directly above a show window of a
department store for each __________
linear feet of show window area.
A. Six
B. Eight
C. Ten
D. Twelve
O 16. D
O 210.62
O 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 __________________?
A. 12 inches
B. 18 inches
C. 10 inches
D. 6 inches
O 17. A
O 470.3
O In movie theaters, all switches for controlling
the emergency lighting systems shall be
located __________.
A. On the stage
B. In the lobby
C. In the manger’s office
D. In the project booth
O 18. B
O 700.21
O Where a 90 ampere, 240-volt, single-phase
load is located 225 feet from a panelboard
and is supplied with size 3 AWG copper
conductors, determine the approximate
voltage drop on the conductors. (K=12.9)
A. 6 volts
B. 4 volts
C. 8 volts
D. 10 volts
O 19. D
O VD= 2KDI/CM
O 2x12.9x225x90/52620= 9.92
O A one-family residence is served with
insulated 120/240 colt service-drop
conductors, 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 5
feet above the water level. The NEC®
requires the conductors to be a Minimum
height of ______ above the pool water level.
A. 25 feet
B. 14 ¼ feet
C. 22 ½ feet
D. 19 ½ feet
O 20. C
O Fig. 580.8
O Tbl. 680.8
O Given: A trade size 2 in. electrical metallic
tubing (EMT) containing four (4) size 2/0
AWG THWN copper conductors is to be
installed in a pull box for a straight pull of
the conductors. What is the MINIMUM
required length of the pull box?
A. 4 inches
B. 12 inches
C. 16 inches
D. 24 inches
O 21. C
O 314.28
O 2x8= 16
O In a commercial garage work area, which of
the following receptacles, if any, are required
to have GFCI protection?
 I. 15 ampere general-purpose
receptacles for hand tools and portable
lights.
 II. 20 ampere receptacles serving
electrical diagnostic equipment only.
A. I only
B. II only
C. Both I and II
D. Neither I and II
O 22. C
O 210.8(B)(8)
O 511.12
O Conductors tapped from a feeder and
supplying the primary of a transformer need
not have overcurrent protection, if the length
of the tap conductors are not over 25 feet
and have an ampacity of at LEAST ______ of
the rating of the overcurrent device
protecting the feeder conductors.
A. One-third
B. One-half
C. 80 percent
D. 75 percent
O 23. A
O 240.21(B)(3)(1)
O Where conductors carrying alternating
current are installed in ferrous metal
raceways, ________.
All phase conductors, the grounded
conductor and equipment grounding
conductors shall be grouped together
B. The phase conductors shall not be grouped
with the grounded conductor
C. The equipment grounding conductor is not
permitted to be in the same raceway with
the grounded and ungrounded conductors
D. The equipment grounding conductors are
not permitted to be installed in a common
raceway with the grounded conductors.
A.
O 24. A
O 300.20(A)
O When connecting utilization equipment to a
20-ampere rated branch-circuit that also
serves luminaires (lighting fixtures), the
utilization equipment shall have an ampere
rating of NOT more than _______.
10 amperes
B. 15 amperes
C. 16 amperes
D. 12 amperes
A.
O 25. A
O 210.23(A)(2)
O 20A x 50%= 10 A