Capítulo 3
Note: For the following problems, you may refer to the NEC to obtain the answers. To help you find
these answers, references to Code sections are included after some of the problems. These references
are not given in later reviews, where it is assumed that you are becoming familiar with the Code.
1. What is the meaning of calculated load? Estimated load based on nominal values.
2. How are branch circuits rated? See NEC 210.3. Branch circuit rating is based on the overcurrent
protection (breaker).
3. How is the rating of the branch-circuit protective device affected when the conductors used are of a
larger size than called for by the Code? See NEC 210.3. IB It is not affected. Rating of the branch circuit
is determined by the overcurrent protection and not the conductor ampacity.
4. What dimensions are used when measuring the area of a building? See NEC 220.12. Dimensions form
the occupied areas of the building.
5. What spaces are not included in the floor area when calculating the load in volt-amperes per square
foot? See NEC 220.12. Open porches, garages, or other unfinished or unused spaces if they are not
adaptable for future use.
12. How many lighting branch circuits are provided in this dwelling? 27
a. What is the minimum load allowance for small-appliance circuits for dwellings? See NEC 220.52(A). 2
b. An individual 15-ampere branch circuit is run to the receptacle outlet behind the refrigerator instead
of connecting it to one of the two 20-ampere small-appliance branch circuits that are required in
kitchens. For this separate circuit, an additional 1500 volt-amperes (shall) (does not have to) be added
to the load calculations for dwellings. (Circle the correct answer.)
13. What is the smallest size wire that can be used in a branch circuit rated at 20 amperes? 12AWG
14. How is the load determined for outlets supplying specific appliances? See NEC 220.14. Considering a
correction or derating factor of 80%.
15. What type of circuits must be provided for receptacle outlets in the kitchen, pantry, dining room,
and breakfast room? See NEC 210.11(C)(1). General purpose circuits.
16. How is the minimum number of receptacle outlets determined for most occupied rooms? See NEC
210.52(A). No point on the wall more than 6ft from a receptacle.
17. In a single-family dwelling, how is overcurrent protection for branch circuits required to be
provided? See NEC 210.20. Overcurrent protection (breaker) should be smaller than wire ampacity.
18. The NEC in Article 100 defines a continuous load as “A load where the maximum current is expected
to continue for three hours or more”.* According to 210.19(A)and 210.20(A), the branch-circuit
conductors and overcurrent protection for a continuous load shall be sized at not less than (100%)
(125%) (150%) of the continuous load. (Circle the correct answer.)
19. The minimum number of outdoor receptacles for a residence is ______2____________, NEC
_____210.52(E)_____. State the location. ___front and back_______________.
20. The Code indicates the rooms in a dwelling that are required to have switched lighting outlets or
switched receptacles. Write “yes” (switch required) or “no” (switch not required) for the following areas
[see NEC 210.70(A)]:
a. attic _____Yes_________________
b. stairway ____ Yes __________________
c. crawl space (where used for storage) ____ Yes __________________
d. hallway ______ Yes ________________
e. bathroom _____ Yes _________________
f. clothes closet ___No___________________
21. Is a receptacle required in a bedroom on a 3 ft (900 mm) wall space behind the door? The door is
normally left open. Yes
22. The Code requires that at least one 20-ampere circuit feeding a receptacle outlet must be provided
for the laundry. May this circuit supply other outlets? No
23. In a basement, at least one receptacle outlet must be installed in addition to the receptacle outlet
installed for the laundry equipment. This additional receptacle outlet and any other receptacle outlets in
unfinished areas must be_____GFCI_____ protected.
24. NEC 210.8(A)(3) requires all receptacles installed outdoors to have GFCI protection. Explain the
exception and describe the conditions of the exception. Exempt from this requirement are GFCI outdoor
receptacle(s) that are not readily accessible and are supplied by a dedicated branch circuit installed for
snow- and ice-melting equipment (e.g., heating cables).
25. Define a branch circuit. Part of the electrical system that connects the service panel to the load.
26. Although the Code contains many exceptions to the basic overcurrent protection requirements for
conductors, in general, the rating of the branch-circuit overcurrent device must (not be less than) (not
be more than) the ampacity of a conductor. (Circle the correct answer.)
27. The rating of a branch circuit is based on (Circle the correct answer.)
a. the rating of the overcurrent device.
b. the length of the circuit.
c. the branch-circuit wire size.
28.
a. A 25-ampere branch-circuit conductor is derated to 70%. It is important to provide proper overcurrent
protection for these conductors. The derated conductor ampacity is _25A*0.70=17.5A_________.
b. If the connected load is a “fixed” nonmotor, noncontinuous load, the branch-circuit overcurrent
device may be sized at (20) (25) amperes. (Circle the correct answer.)
c. If the above circuits supply receptacle outlets, the branch-circuit overcurrent device must be sized at
not over (15) (20) (25) amperes. (Circle the correct answer.)
29. Small-appliance receptacle outlets are (included) (not included) in the 3-volt-ampereper-square-foot
calculations. (Circle the correct answer.)
30. If a homeowner wishes to have a switched receptacle outlet for a swag lamp in a dining room, may
this switched receptacle outlet be considered to be one of the receptacle outlets required for the 20ampere small-appliance circuits? Yes
31. How many receptacle outlets are required on a 13 ft (4.0 m) wall space between two doors? Refer to
NEC 210.52(H). Draw the outlets on the diagram. 2
32. Is a receptacle required in a hallway in a home when the hallway is 8 ft (2.5 m) long? No
33. A split-level home has one stairway that has six risers between two levels of the home. Which of the
following choices Meets Code? (Circle the correct answer.)
a. Two three-way switches must be installed (one switch at the top of the stairs, one switch at the
bottom of the stairs) to control the lighting for the stairway.
b. One single-pole switch is permitted on either level to control the lighting for the stairway.
c. No switches are necessary for the stairway lighting because the lighting on the upper level and the
lower level provides enough illumination on the stairway.
34. A sliding glass door is installed in a family room that leads to an outdoor deck. The sliding door has
one 4 ft (1.22 m) sliding section and one 4 ft (1.22 m) permanently mounted glass section. For inside the
recreation room, what does the Code say about wall receptacle outlets relative to the receptacle’s
position near the sliding glass door? There must be a switch to control lighting outside the glass door.
35. When determining the location and number of receptacles required, fixed room dividers and railings
(shall be) (need not be) considered to be wall space. (Circle the correct answer.)
36. No point along the wall line shall be more than 6 ft (1.8 m) from a receptacle outlet. This
requirement (does apply) (does not apply) to unfinished residential basements. (Circle the correct
answer.)
37. In the past, it was common practice to connect the lighting and receptacle(s) in a bathroom to the
same circuit. Because of overloads caused by high-wattage grooming appliances, the Code now requires
that these receptacle(s) be supplied by a separate 20-ampere branch circuit. Where in the Code is this
requirement found? NEC ___ 210.11(C)(3)_____
38. If a residence has two bathrooms, the Code states:
a. The receptacles in each bathroom must be connected to a separate 20-ampere branch circuit. For two
bathrooms, this would mean two circuits. (True) (False) (Circle the correct answer.)
b. The receptacles in both bathrooms are permitted to be served by the same 20-ampere branch circuit.
(True) (False) (Circle the correct answer.)
39. In your own words, explain the GFCI exemptions for receptacle outlets installed in unfinished
basements. Give some examples.
40. NEC ____210.25__________________ of the Code prohibits connecting lighting and/or
fire/smoke/security systems to an individual tenant’s electrical source where common (shared) areas
are present, in which case the lighting provided for both tenants is connected on one tenant’s electrical
source.
41. When installing weatherproof outdoor receptacles high up under the eaves of a house intended to
be used for plugging in deicing and snow-melting cable for the rain gutters, must these receptacles be
GFCI protected for personnel protection? (Yes) (No) (Circle the correct answer.)
42. An individual 20-ampere branch circuit supplies a receptacle for a refrigerator. The receptacle shall
be or is permitted to be
a. a duplex receptacle.
b. a single receptacle.
Explain why you chose your answer.
43. A balcony on the second floor of a new residence measures 4 ft (1.22 m) x 10 ft (3.05 m). The
balcony is accessed by a sliding door. Is a receptacle required for this balcony? Circle the correct answer,
and give the NEC section where the answer is found. Yes __X___ No_____ NEC __________________