Question 1

In the diagram below, label the type of circuit represented by each part of the installation, choosing from among the following. You may or may not require all the types listed.  Power supply wiring
Class 1 wiring
Class 2 wiring
Class 3 wiring
Communications wiring

Accepted Answer

A = Class 2 wiring
B...

Question 2

Oil-fired heating systems move hot air from the furnace through hot air ducts that in turn connect to hot air registers strategically located throughout the home.

Accepted Answer

A) True 
 B)False

Question 3

Manufacturers of heating and cooling equipment provide separate openings for bringing in the Class 2 wiring and separate openings for bringing in the power supply.

Accepted Answer

A) True 
 B)False

Question 4

Class 2 wiring ____ permitted in the same raceway, cable, compartment, outlet box, or fitting with light and power conductors, even if the Class 2 conductors have the same 600-volt insulation as the power conductors.

Accepted Answer

A)   is
B)   is notC) A) and B)
D) undefined

Question 5

Class 2 power source voltage limitations, current limitations, and overcurrent protection requirements are found in ____.

Accepted Answer

A)   Article 220
B)   Article 240
C)   Article 725
D)   Chapter 9, Tables 11(a)  and 11(b) E) A) and D)
F) B) and C)

Question 6

Which of the following is NOT a typical Class 2 wiring application in homes?

Accepted Answer

A)   thermostats
B)   security systems
C)   doorbell chimes
D)   low-voltage lightingE) A) and B)
F) C) and D) D

Question 7

Hot water systems are very adaptable to zone control by using a combination of one or more circulating pumps and/or valves for the different zones. Hot water heating systems are referred to as ____________________ systems.

Accepted Answer

The answer of Hot water systems are very adaptable to...

Question 8

NEC 422.12 requires that central heating equipment of any type (electric resistance, gas, oil, heat pump)  must ____.

Accepted Answer

A)   have a disconnect mounted within sight of the unit
B)   be supplied by an individual branch circuit
C)   have a supplemental power source
D)   both b and cE) A) and B)
F) A) and C)

Question 9

Because they have internal overload protection, listed Class 2 transformers are permitted to be supplied by branch circuits having overcurrent protection not exceeding ____ amperes.

Accepted Answer

A)   15
B)   20
C)   30
D)   50E) B) and C)
F) None of the above

Question 10

Most residential heating systems are packaged units in which many items are preassembled, prewired parts of the furnace or boiler. They are included in an integrated printed circuit board module, which is the "____" of the system.

Accepted Answer

A)   core
B)   brain
C)   guts
D)   heartE) A) and B)
F) All of the above

Question 11

Do not throw selenium thermostats into the trash because the selenium is considered hazardous waste material.

Accepted Answer

A) True 
 B)False  False

Question 12

How does the Code define a remote-control circuit?

Accepted Answer

A remote-control circuit is an...

Question 13

Residential thermostats should be located where they will not be influenced by ____.

Accepted Answer

A)   drafts or currents from air registers
B)   radiated heat from appliances, lamps, etc.
C)   direct rays of the sun
D)   all of the aboveE) A) and D)
F) All of the above

Question 14

A remote-control circuit is any electrical circuit that ____________________ through a relay or equivalent device.

Accepted Answer

controls a...

Question 15

____ circuits offer alternative wiring methods regarding voltage, power limitations, wire size, derating factors, overcurrent protection, physical protection, insulation, and materials that differentiate these types of circuits from conventional wiring methods.

Accepted Answer

A)   Class 1
B)   Class 2
C)   Class 3
D)   all of the aboveE) A) and D)
F) B) and D)

Question 16

Low-voltage wiring used for door bell and thermostat wiring in a residence is generally Class 2 wiring, which has a thermoplastic insulation with a voltage rating of not less than ____________________ volts.

Accepted Answer

The answer of Low-voltage wiring used for door bell and...

Question 17

Disconnect switches for furnaces installed in basements are required to be ____.

Accepted Answer

A)   suitable for damp locations
B)   installed within sight of the appliance
C)   fused
D)   all of the aboveE) C) and D)
F) B) and D)

Question 18

Explain the purpose of interrupted duty ignition on a gas furnace.

Accepted Answer

An interrupted duty ignition system is e...

Question 19

Class 2 circuits are ____________________ and are considered safe from fire hazard and from electric shock hazard

Accepted Answer

"power-limited"
"power limited"
power limited
power-limited

Question 20

Thermostats are usually mounted approximately ____ in. above the finished floor.

Accepted Answer

A)   36
B)   52
C)   60
D)   76E) All of the above
F) B) and C)

Exam 24: Gas and Oil Central Heating Systems

In the diagram below, label the type of circuit represented by each part of the installation, choosing from among the following. You may or may not require all the types listed. Power supply wiring Class 1 wiring Class 2 wiring Class 3 wiring Communications wiring

Correct AnswerverifiedA = Class 2 wiringB...View AnswerShow Answer

Oil-fired heating systems move hot air from the furnace through hot air ducts that in turn connect to hot air registers strategically located throughout the home.

Correct AnswerverifiedShow Answer

Manufacturers of heating and cooling equipment provide separate openings for bringing in the Class 2 wiring and separate openings for bringing in the power supply.

Correct AnswerverifiedShow Answer

Class 2 wiring ____ permitted in the same raceway, cable, compartment, outlet box, or fitting with light and power conductors, even if the Class 2 conductors have the same 600-volt insulation as the power conductors.

Correct AnswerverifiedShow Answer

Class 2 power source voltage limitations, current limitations, and overcurrent protection requirements are found in ____.

Correct AnswerverifiedShow Answer

Which of the following is NOT a typical Class 2 wiring application in homes?

Correct AnswerverifiedD

Hot water systems are very adaptable to zone control by using a combination of one or more circulating pumps and/or valves for the different zones. Hot water heating systems are referred to as ____________________ systems.

Correct AnswerverifiedShow Answer

NEC 422.12 requires that central heating equipment of any type (electric resistance, gas, oil, heat pump) must ____.

Correct AnswerverifiedShow Answer

Because they have internal overload protection, listed Class 2 transformers are permitted to be supplied by branch circuits having overcurrent protection not exceeding ____ amperes.

Correct AnswerverifiedShow Answer

Most residential heating systems are packaged units in which many items are preassembled, prewired parts of the furnace or boiler. They are included in an integrated printed circuit board module, which is the "____" of the system.

Correct AnswerverifiedShow Answer

Do not throw selenium thermostats into the trash because the selenium is considered hazardous waste material.

Correct AnswerverifiedFalse

How does the Code define a remote-control circuit?

Correct AnswerverifiedA remote-control circuit is an...View AnswerShow Answer

Residential thermostats should be located where they will not be influenced by ____.

Correct AnswerverifiedShow Answer

A remote-control circuit is any electrical circuit that ____________________ through a relay or equivalent device.

Correct Answerverifiedcontrols a...View AnswerShow Answer

____ circuits offer alternative wiring methods regarding voltage, power limitations, wire size, derating factors, overcurrent protection, physical protection, insulation, and materials that differentiate these types of circuits from conventional wiring methods.

Correct AnswerverifiedShow Answer

Low-voltage wiring used for door bell and thermostat wiring in a residence is generally Class 2 wiring, which has a thermoplastic insulation with a voltage rating of not less than ____________________ volts.

Correct AnswerverifiedShow Answer

Disconnect switches for furnaces installed in basements are required to be ____.

Correct AnswerverifiedShow Answer

Explain the purpose of interrupted duty ignition on a gas furnace.

Correct AnswerverifiedAn interrupted duty ignition system is e...View AnswerShow Answer

Class 2 circuits are ____________________ and are considered safe from fire hazard and from electric shock hazard

Correct Answerverified"power-limited" "power limited" power limited power-limited

Thermostats are usually mounted approximately ____ in. above the finished floor.

Correct AnswerverifiedShow Answer

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A = Class 2 wiring
B...
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D

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False

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A remote-control circuit is an...
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controls a...
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An interrupted duty ignition system is e...
View Answer

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"power-limited" "power limited" power limited power-limited

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