Deck 14: Branch-Circuit Installation

Question 1

The NEC permits low-voltage Class 2 doorbell cable to be run next to 120- or 240-volt branch circuits wired with nonmetallic sheathed cable.

Answer 1

True

Question 2

Electric ranges installed in houses are typically wired for __________-volt operation.

A) 120
B) 208
C) 240
D) 120/240

Answer 2

D

Question 3

A receptacle for a gas-fired range is permitted to be connected to a small appliance circuit in a kitchen.

Answer 3

True

Question 4

The receptacle installed for a clothes washing machine located in a laundry area of an unfinished basement or a bathroom must be GFCI protected.

Question 5

In the NEC, a bathroom is defined as an area that has a basin, a toilet, and a __________.

A) urinal
B) tub
C) shower
D) Any of the above

Question 6

The working space requirements of Section 110.26 in the NEC must be maintained when the disconnecting means for an air-conditioning unit on the outside of the house is installed.

Question 7

The NEC requires at least one 15- or 20-ampere, 125-volt receptacle in a bathroom and it must be located no more than __________ inches from the outside edge of the basin.

A) 8
B) 12
C) 30
D) 36

Question 8

If a new electric clothes dryer is being installed in a home built before 1996 that has a three-wire cord-and-plug connection, the circuit must be replaced to accept a four-wire cord and plug.

Question 9

In older smoke detectors, the interconnect wire was colored yellow, but newer smoke detectors are using a red interconnect wire.

Question 10

In a laundry room, receptacles must be placed so that no point along the wall is more than 6' from a receptacle.

Question 11

If a counter-mounted cooktop unit has a nameplate rating of 7300 watts at 240 volts, the current draw will be __________ amperes.
a.
30.41
b.
41.65
c.
60.83
d.
72.6

Question 12

Smoke detectors in homes must be hardwired to the electrical system but may have battery backup.

Question 13

There is no maximum number of receptacles allowed on 15- or 20-ampere branch circuits in a house according to the NEC but it is suggested that the maximum number of receptacles permitted on a 15-ampere rated circuit be no more than 10 and the maximum number of receptacles permitted on a 20-ampere rated circuit be no more than __________.

A) 12
B) 13
C) 14
D) 15

Question 14

A(n) __________ circuit breaker has a trip time that gets faster as the fault current flowing through it gets larger.

A) dual-element
B) inverse time
C) plug fuse
D) type S

Question 15

In an electric motor circuit, the size of the circuit breaker and the circuit conductors is determined by the __________ of the motor.

A) horsepower rating
B) full load current
C) voltage rating
D) All of the above

Question 16

A general lighting branch circuit installed in a house and protected by a 15-ampere circuit breaker may be wired with a __________ AWG copper conductor.

A) 14
B) 12
C) 10
D) Any of the above

Question 17

Electric water heaters must be wired with a three-wire cable because the white conductor in a two-wire cable is not permitted to be used as an ungrounded conductor in this type of installation.

Question 18

A receptacle located under a kitchen sink for a cord-and-plug-connected garbage disposal must be GFCI protected.

Question 19

HACR is an acronym found on some circuit breakers and stands for "heating, air conditioning, and ventilation."

Question 20

The minimum number of small appliance circuits required by the NEC in each house is __________.

A) 1
B) 2
C) 3
D) 4

Question 21

The NEC requires that small appliance branch circuits be protected with ____________________-ampere overcurrent protection devices.

Question 22

On an individual branch circuit where no other items are served by the circuit, an air conditioner load cannot exceed __________ of the branch-circuit ampacity.

A) 50%
B) 70%
C) 80%
D) 100%

Question 23

Which NEC Table will tell you the full load current for a single-phase electric motor?

A) Table 310.15(B)(16)
B) Table 430.248
C) Table 8, Chapter 9
D) Table 430.250

Question 24

A(n) __________-colored switch cover is used to identify an oil burner safety switch.

A) orange
B) red
C) blue
D) yellow

Question 25

The chime transformer is used to transform the 120-volt residential circuit voltage down to the voltage that a chime system will operate on, usually ____________________ volts.

Question 26

When determining the amount of electric heating to be installed in a house, the rule of thumb is to use _______ watts per square foot for each heated area in a house.

A) 10
B) 100
C) 1
D) 50

Question 27

The NEC requires a laundry circuit to be rated at ____________________ amperes.

Question 28

When installing a receptacle for a cord-and-plug connected appliance, the receptacle must be located no more than __________ feet from the appliance.

A) 2
B) 5
C) 6
D) 8

Question 29

If an electric clothes dryer has a rating of 6 kilowatts at 120/240 volts, it will draw ____________________ amperes.

Question 30

A wall-mounted electric oven has a nameplate rating of 9 kilowatts at 240 volts.The rated current is ____________________ amperes.

Question 31

If an electric water heater is connected to water piping with connections that are designed so that the water heater can be quickly and easily removed, a flexible cord-and-plug connection is allowed.

Question 32

A hot water heating system is sometimes referred to as a(n) __________ heating system.

A) forced air
B) gas
C) electric
D) hydronic

Question 33

Who decides whether 15- or 20-ampere rated general lighting circuits will be installed in a residential electrical system?

A) The homeowner
B) The architect
C) The electrical contractor
D) The plumber

Question 34

Where should carbon monoxide (CO) alarms be mounted?

A) Near bedrooms and living areas
B) Where occupants where hear the alarm while sleeping
C) On each level of a home and out of reach of children
D) All of the above

Question 35

Most residential electric water heaters operate on 240 volts, are wired with 10 AWG conductors, and are protected with a __________-ampere overcurrent protection device.

A) 20
B) 30
C) 40
D) 50

Question 36

A ____________________-ampere overcurrent protection device is required for a residential general-purpose branch circuit wired with a 12 AWG copper conductor.

Question 37

While there is no limit to the number of receptacles that can be connected to a general lighting branch circuit, a good rule of thumb is to assign each receptacle outlet a value of ____________________ amperes.

Question 38

The NEC requires most motor applications to be protected by overload devices sized not more than __________ of the motor's nameplate current rating.

A) 100%
B) 115%
C) 125%
D) 150%

Question 39

Which table in the NEC is used to determine the maximum rating of the motor short circuit and ground-fault protection device (fuse or circuit breaker)?

A) Table 250.66
B) Table 310.104(A)
C) Table 430.52
D) Table 8, Chapter 9

Question 40

Instead of installing the required bathroom receptacle on a wall or partition adjacent to the basin, it may be installed on the side or face of the basin cabinet, as long as it is located no more than __________ inches below the countertop.

A) 6
B) 12
C) 18
D) 24

Question 41

List all of the locations of a house where AFCI protection for the branch circuits supplying those locations is required.

Question 42

Explain why some areas of the country have a high number of homes heated by electric heat, while in other parts of the country most homes are heated by oil or gas.

Question 43

Discuss some of the drawbacks to wireless chimes.

Question 44

Explain what a carbon monoxide detector does.

Question 45

A(n) _________________________________ is a fuse type that has a time-delay feature built into it and is often used as an overcurrent protection device for electric motor circuits.

Question 46

When an installation technique is used that brings the circuit conductors directly to an electrical appliance and then terminates them at the appliance, the appliance is said to be ____________________.

Question 47

Explain how smoke detectors work.