Deck 6: Determining Branch Circuit, Feeder Circuit, and Service Entrance Requirements

Question 1

When doing branch circuit, feeder, and service entrance calculations, one volt-amp equals __________.

A) one joule
B) one watt
C) one ohm
D) one mil

Answer 1

B

Question 2

A supplemental grounding electrode is a grounding electrode used to 'back-up' a metal water pipe grounding electrode.

Answer 2

True

Question 3

When doing a service entrance calculation, if a residence has four fixed appliances, a demand factor of __________% is applied to the total load of these appliances.

A) 50
B) 75
C) 80
D) 100

Answer 3

B

Question 4

A(n) __________ is the circuit conductors between the final overcurrent device and the outlets.

A) open circuit
B) branch circuit
C) feeder circuit
D) service conductor

Question 5

Which of the following areas is included when computing the general lighting load of a house?

A) Open Porches
B) Garages
C) Crawl spaces
D) Finished basements

Question 6

Which of the following is not permitted to be connected to a small appliance branch circuit?

A) Refrigerator
B) Electric clock
C) Gas stove
D) Kitchen lighting fixture

Question 7

Which of the following loads does not require a grounded conductor?

A) 2-wire, 120 volt
B) 3-wire, 120/240 volt
C) 2-wire, 240 volt
D) None of the above

Question 8

According to the NEC, the unit load used to calculate the minimum number of general lighting circuits in a dwelling is __________ volt-amperes per square foot.

A) 2
B) 3
C) 4
D) 5

Question 9

An point on the wiring system at which current it taken to supply electrical equipment is called a receptacle.

Question 10

All of the following types of branch circuits are found in residential wiring except:

A) general lighting
B) laundry
C) large appliance
D) small appliance

Question 11

If cables are bundled together for more than 24" and the total number of current-carrying conductors exceeds __________, the ampacity of the conductors must be derated.

A) 2
B) 3
C) 4
D) 5

Question 12

When cables or conductors are physically tied, wrapped, or taped together, they are considered to be ______________.

A) bundled
B) messy
C) supported
D) secured

Question 13

When doing a service entrance calculation and applying the demand factor to the total load of the general lighting load, the small appliance circuits, and the laundry circuit, the first ___________ volt-amps are computed at 100%

A) 2,000
B) 2,500
C) 3,000
D) 4,000

Question 14

A house with 2,000 square feet of habitable living space will require at least _________ general lighting circuits if 15-ampere circuit breakers are used to provide circuit protection.

A) 3
B) 4
C) 5
D) 6

Question 15

In a residential wiring, which of the following house areas does not have its power supplied by a small appliance circuit?

A) Bathroom
B) Dining room
C) Kitchen
D) Pantry

Question 16

The rating of a panelboard is based on the ampacity of the __________.

A) main breaker
B) buss bar
C) service conductor
D) total amperage of each breaker in the panelboard

Question 17

A 200-ampere rated panel is designed and manufactured to accommodate __________ circuits.

A) 30
B) 40
C) 42
D) Could be any of the above

Question 18

The circuit conductors between the service equipment and the final branch circuit overcurrent protection device is a(n) __________.

A) open circuit
B) branch circuit
C) feeder circuit
D) service conductor

Question 19

Kitchen lighting outlets are permitted to be connected to any of the small appliance branch circuits that provide power for the kitchen receptacles.

Question 20

The minimum service entrance rating for a single-family home permitted by the NEC is __________ amperes.

A) 60
B) 75
C) 100
D) 200

Question 21

According to NEC Table 310.15(B)(7) in the 2011 NEC, the minimum conductor size for a 200 ampere residential service entrance is _________ CU or _________ AL.

A) 4 AWG; 2 AWG
B) 3 AWG; 1 AWG
C) 2 AWG; 1/0 AWG
D) 2/0 AWG; 4/0 AWG

Question 22

If an electric dryer has a nameplate rating of 4,500 watts, ____________________ watts will be used in the standard method service calculation.

Question 23

The NEC requires at least ____________________ small appliance circuits be installed in each dwelling unit.

Question 24

If the total computed load of a residence is 45,840 volt-amperes, the computed amperage of the residence is ____________________ amps.

Question 25

For the types of branch circuits found in residential wiring, the fuse or circuit breaker size can never be larger than ____________________ amps for a 12 AWG copper conductor.

Question 26

List at least 5 types of branch circuits found in residential wiring.

Question 27

Explain when sub-panels are used in residential wiring.

Question 28

According to Table 310.15(B)(16) in the 2011 NEC, the ampacity for a 3 AWG copper conductor using the 75 degree Celsius column is ____________.

A) 85 amps
B) 95 amps
C) 100 amps
D) 200 amps

Question 29

The NEC states that the load for a household electric dryer must be computed at ____________________ watts or the nameplate rating, whichever is greater.

Question 30

A 1900 square foot residence has a general lighting load of ____________________ volt-amperes.

Question 31

Explain when bathroom lighting is permitted to be connected to the 20-amp rated bathroom branch circuit.

Question 32

____________________ is the current in amperes that a conductor can carry continuously under certain conditions of use without exceeding its temperature rating.

Question 33

A household electric range has a rating of 11 kW. When computing the service load, a minimum of ____________________ watts will be used.

Question 34

The NEC states that each two-wire small appliance circuit shall be computed at ____________________ volt-amperes.

Question 35

Dividing the total computed load in volt-amperes by the service voltage of ____________________ volts will give the minimum ampacity the service conductors must be rated for.

Question 36

Another way to calculate the minimum number of general lighting circuits required in a dwelling unit is to divide the total habitable square foot living area by ____________ square feet for 15 amp branch circuits and ______________ square feet for 20 amp branch circuits.

A) 200/300
B) 600/800
C) 750/1000
D) 1500/2000

Question 37

According to NEC Table 310.15(B)(7) in the 2011 NEC, the minimum conductor size for a 300 ampere residential service entrance is _________ CU or _________ AL.

A) 2 AWG; 1/0 AWG
B) 2/0 AWG; 4/0 AWG
C) 250 kcmil ; 350 kcmil
D) 400 kcmil ; 600 kcmil

Question 38

Explain how the electric heating and the air conditioning loads are computed when calculating the total electrical load for a residential service.

Question 39

____________________ temperature is the temperature of the air that surrounds an object on all sides.

Question 40

According to Table 310.15(B)(16) in the 2011 NEC, the ampacity for a 12 AWG copper conductor using the 60 degree Celsius column is ____________.

A) 20 amps
B) 25 amps
C) 30 amps
D) 40 amps