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G2 EXAM part 1

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Quiz on G2 EXAM part 1, created by toan nguyen on 08/02/2022.
toan nguyen
Quiz by toan nguyen, updated more than 1 year ago
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Created by toan nguyen over 3 years ago
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Resource summary

Question 1

Question
Schedule 80 pipe is required in a propane system:
Answer
  • for propane vapour under 125 psig (860 kPa) working pressure
  • when steel piping is to be connected to plastic piping
  • for propane vapour over 125 psig (860 kPa) working pressure
  • when copper piping is to be connected to plastic pipe

Question 2

Question
When sizing branch line, what is the maximum size a job fabricated welded fitting that can be used in a 6” NPS gas supply
Answer
  • 6” NPS
  • 3” NPS
  • 4” NPS
  • 2” NPS

Question 3

Question
Natural gas piping in industrial buildings shall be identified:
Answer
  • with yellow paint or yellow bands
  • with red paint or red bands
  • with paint in a contrasting colour to other pipes
  • with green paint and yellow bands

Question 4

Question
A panel-mounted ground fault circuit interrupting breaker protects all:
Answer
  • electrical loads in the circuits from that panel
  • loads in the circuit served by that breaker
  • 240 volt circuits served by that breaker panel
  • 120 volt circuits served by that breaker panel

Question 5

Question
Branch circuit fuse size is determined by the:
Answer
  • size of the wire
  • the length of the wire
  • voltage supplied to the appliance
  • type of insulation on the wire

Question 6

Question
The 24 volt control circuit supply for a residential gas furnace comes from a:
Answer
  • 60/24 volt step down transformer
  • 120/24 volt step down transformer
  • 240/24 step down transformer
  • 240/120 volt step down transformer

Question 7

Question
On an electrical schematic diagram, the safety controls are typically drawn:
Answer
  • to the right of the loads
  • above the loads
  • below the loads
  • to the left of the loads

Question 8

Question
The power supply to a residential gas furnace is:
Answer
  • 120/1/60
  • 120/2/60
  • 240/1/60
  • 240/2/60


Question 9

Question
As gauge number of a conductor increase, its current carrying capacity:
Answer
  • increases
  • decreases
  • remains the same
  • varies directly

Question 10

Question
As more circuits are added to a panel, the total current drawn from the panel:
Answer
  • Increases
  • decreases
  • remains the same
  • fluctuates

Question 11

Question
A hard, sharp pilot flame indicates
Answer
  • the orifice is too small
  • there is a lack of air
  • there is excessive draft at the pilot location
  • high gas pressure

Question 12

Question
Direct current travels:
Answer
  • only from the load directly to the source
  • in one direction only
  • only from the source directly to the load
  • across the load only

Question 13

Question
A receptacle-mounted ground fault interrupter protects against:
Answer
  • appliance overload
  • dead shorts
  • short circuits
  • current flow to ground

Question 14

Question
On an electrical schematic, the system is shown with the:
Answer
  • disconnect closed with all devices as though the heating is on
  • disconnect closed with all devices as though there is a call for heating but the heating has not yet come on
  • disconnect open with all devices as though there is a call for heating
  • disconnect open with all devices as though there is no call for heating

Question 15

Question
The normal fuse size for #12 AWG copper wire is:
Answer
  • 15 amps
  • 20 amps
  • 30 amps
  • 40 amps

Question 16

Question
A zero ohmmeter reading taken between the casing of a solenoid and a disconnected wire to the solenoid indicates that:
Answer
  • the coil is good
  • the coil is shorted to the casing of the device
  • the coil wire is broken
  • all of the available choices

Question 17

Question
As the diameter of a conductor decreases, its resistance:
Answer
  • Increases
  • decreases
  • remains the same
  • varies directly

Question 18

Question
When can an on/off switch be installed in the neutral wire from an electrical panel to a gas furnace:
Answer
  • never
  • only when it carries 24 volts or less
  • only when the switch is 3 feet or less from the appliance
  • only when the supply is 240 volts

Question 19

Question
A thermostat with a single mercury bulb which controls a single stage heat, single stage cool unit is a ___________ control:
Answer
  • SPST (single pole single throw)
  • SPDT (single pole double throw)
  • DPST (single pole single throw)
  • DPDT (double pole double throw)

Question 20

Question
How tight should a thermocouple connection be:
Answer
  • finger tight
  • ¼ turn past finger tight
  • 1 ½ turns past finger tight
  • two turns with a wrench

Question 21

Question
What happens to the resistance inside an infrared scanner when the scanner is exposed to infrared radiation:
Answer
  • resistance increases
  • resistance decreases
  • resistance remains the same
  • resistance fluctuates

Question 22

Question
What is required combustion air inlet size for a stationary gas engine having an input of 1,800,000 Btuh installed in a room?
Answer
  • 30 square inches (1,800 mm2)
  • 60 square inches (3,900 mm2)
  • 120 square inches (7,800 mm2)
  • 180 square inches (11,600 mm2)

Question 23

Question
After correctly sizing an air intake opening, the grill or screen should cover the opening.
What is the minimum size of the mesh on an air intake grill?
Answer
  • 3/32” (2 mm)
  • 1/8” (3 mm)
  • 1/4” (6 mm)
  • 1/2" (12 mm)

Question 24

Question
The most important element required for proper combustion in a gas appliance is:
Answer
  • carbon dioxide
  • air
  • nitrogen
  • water vapour

Question 25

Question
The best method of removing dust from a house is:
Answer
  • humidification
  • infiltration
  • filtration
  • exfiltration

Question 26

Question
To reduce heat loss, the most effective thing to do is to:
Answer
  • add attic insulation
  • install new windows
  • seal air leaks
  • install a heat recovery unit

Question 27

Question
The best way to remove odours from a house is to:
Answer
  • filter the air in the house
  • ventilate the house
  • install mechanical attic ventilation
  • humidify the air in the house

Question 28

Question
The maximum negative building pressure that a natural draft vented appliance should be exposed to is:
Answer
  • 5 Pa (- 0.02” w.c.)
  • 10 Pa (- 0.04” w.c.)
  • 15 Pa (- 0.06” w.c.)
  • 20 Pa (- 0.08” w.c.)

Question 29

Question
After a direct vent radiant heating system is installed in a new house, the customer complains that, “The walls and windows are wet.” From the following list, what is the most reasonable response?
Answer
  • after confirming the heat exchanger is not cracked, advise the customer to call for someone else
  • recommend that a window be left open a bit
  • advise the customer that the problem will disappear when the building dries out
  • recommend the installation of a mechanical ventilation system

Question 30

Question
Indoors in winter, if a vapour barrier has not been made continuous, the:
Answer
  • relative humidity will increase
  • relative humidity will decrease
  • heat gain will occur
  • heat loss will decrease

Question 31

Question
From the following list, which action will have the greatest effect on reducing mold growth in the house?
Answer
  • reducing relative humidity to approximately 10%
  • increasing relative humidity to approximately 80%
  • filtering the air in the house
  • covering earthen floors and open water surfaces

Question 32

Question
Which of the following actions will limit the problems caused by the “distribution effect” on conventional vented forced air furnaces?
Answer
  • seal the ductwork in the furnace area
  • balance the volume of return and supply air in each room or floor
  • ensure a tight seal around the furnace filter and blower door
  • all of the available choices

Question 33

Question
Currently, the most common type of building construction is:
Answer
  • balloon
  • platform
  • double brick
  • solid brick

Question 34

Question
The main purpose of the building skin is to:
Answer
  • protect the underlying materials
  • reduce heat gain
  • improve resistance to vapour flow
  • maintain the depressurization limit

Question 35

Question
The “systems approach” as it applies to a building is a means of understanding how fuel-fired appliances affect and are affected by the:
Answer
  • outside environment
  • building
  • occupants
  • all of the available choices

Question 36

Question
Which symbol represents a gas solenoid?
Image:
Screen+Shot+2022 02 08+At+00.10.56 (binary/octet-stream)
Answer
  • 4
  • 5
  • 6
  • 7

Question 37

Question
Which symbol represents the dryer heat thermostat?
Image:
Screen+Shot+2022 02 08+At+00.10.56 (binary/octet-stream)
Answer
  • 1
  • 2
  • 3
  • 4

Question 38

Question
Which symbol represents a dryer high limit switch?
Image:
Screen+Shot+2022 02 08+At+00.10.56 (binary/octet-stream)
Answer
  • 1
  • 3
  • 4
  • 7

Question 39

Question
Which symbol represents a dryer centrifugal switch?
Image:
Screen+Shot+2022 02 08+At+00.10.56 (binary/octet-stream)
Answer
  • 1
  • 4
  • 6
  • 7

Question 40

Question
Which symbol represents a dryer pilot switch?
Image:
Screen+Shot+2022 02 08+At+00.10.56 (binary/octet-stream)
Answer
  • 1
  • 2
  • 3
  • 7

Question 41

Question
Which symbol represents a timer motor?
Image:
Screen+Shot+2022 02 08+At+00.10.56 (binary/octet-stream)
Answer
  • 4
  • 5
  • 6
  • 7

Question 42

Question
The required clearance to combustible material above a pendant gas lamp is:
Answer
  • 5 inches (125 mm)
  • 12 inches (300 mm)
  • 15 inches (375 mm)
  • 18 inches (450 mm)

Question 43

Question
The mantle of a gas lamp:
Answer
  • provides ignition
  • mixes air and gas
  • protects the igniter
  • changes a blue flame to a luminous flame

Question 44

Question
What is the minimum clearance from the sides of a domestic range to combustible materials, unless otherwise specified?
Answer
  • 1 inches (25 mm)
  • 3 inches (75 mm)
  • 6 inches (150 mm)
  • 9 inches (225 mm)

Question 45

Question
What type of protection does a range require if it is certified for zero side clearance from combustible material?
Answer
  • 28 MSG (0.3 mm) sheet metal spaced out 0.25 inch (6 mm)
  • 28 MSG (0.3 mm) sheet metal applied directly to the combustible material
  • 1/4 inch (6 mm) asbestos millboard
  • no protection required

Question 46

Question
The primary function of a surge arrestor in the top of a regulator is to:
Answer
  • allow the regulator to breath
  • reduce the opening speed of the regulator
  • limit the escape of gas to 1 cu. ft./hour
  • stop the regulator from operating if it is over pressurized

Question 47

Question
Propane containers located on the outside of a recreational vehicle shall be:
Answer
  • mounted securely to the roof of the vehicle
  • mounted on an “A” frame as close to the front of the vehicle as practicable
  • secured ahead of the front bumper
  • secured to the rear of the vehicle

Question 48

Question
A monitor regulator:
Answer
  • is a redundant regulator which backs up the operating regulator
  • controls gas flow to the top of the diaphragm
  • reduces pressure from pounds to ounces
  • remains locked off until it is required

Question 49

Question
What is the maximum outlet pressure for a first stage regulator on a residential propane system?
Answer
  • 11.0” w.c.
  • 11 psi
  • 10.0 psi
  • 15.0 psi

Question 50

Question
For appliances with the same input, the size of the orifice used for a propane appliance should be:
Answer
  • the same size as the orifice used for natural gas
  • larger than the orifice used for natural gas
  • smaller than the orifice used for natural gas
  • < 3% the size of the orifice used for natural gas

Question 51

Question
What does movement of 1/43 ft. dial indicate when completing a gas meter pressure dial test?
Answer
  • the service regulator is malfunctioning
  • the static pressure is excessive
  • the working pressure is low
  • the piping is not gas tight

Question 52

Question
What should be done if it is noticed that a regulator set in a loading dock area is not protected against physical damage?
Answer
  • advise the customer to provide protection as soon as possible
  • notify the local gas utility that protection is required
  • advise the customer to contact the local gas utility
  • report the situation to the Technical Standard and Safety Authority immediately

Question 53

Question
What is the maximum permitted filling density of a cylinder with liquid propane (relative density = 0.51) by liquid volume? (liquid temperature assumed to be 40°F ( 4.5°C)
Answer
  • 42%
  • 60%
  • 80%
  • 90%

Question 54

Question
What will happen if the adjusting screw of a regulator is turned counter-clockwise decreasing the spring pressure?
Answer
  • the downstream pressure will remain the same
  • the downstream pressure will decrease
  • the upstream pressure will increase
  • the upstream pressure will decrease

Question 55

Question
A regulator is sized for the load it is to serve by:
Answer
  • multiplying the appliance input by 1.5 and selecting a regulator in that input range
  • checking the appliance rating plate and selecting a regulator for that input range
  • determining the pipe size of the appliance manifold and selecting a regulator in that input range
  • multiplying the appliance input by 1.25 and selecting a regulator in that input range

Question 56

Question
Which of the following are used in an absorption refrigeration cycle?
Answer
  • ammonia and helium
  • ammonia and hydrogen
  • ammonia and propane
  • ammonia and butane

Question 57

Question
What are the main components of a gas-fired refrigerator?
Answer
  • generator, evaporator, radiator, absorber
  • generator, evaporator, capacitor, absorber
  • generator, evaporator, compressor, absorber
  • generator, evaporator, absorber, condenser

Question 58

Question
Is it permissible to use the propane side of a refrigerator in a recreation vehicle while the vehicle is in motion?
Answer
  • no
  • no, unless the vehicle is only being moved to a more level location
  • yes
  • yes, if the vehicle is being moved 1 mile or less

Question 59

Question
How can the location of a leak in a heat exchanger be determined?
Answer
  • by using a flue gas analyzer and visual examination
  • by using a carbon monoxide detector and visual examination
  • by using a smoke generator and visual examination
  • all of the available choices

Question 60

Question
Why does the recommended range of CO2 in a conventional furnace differ from the ultimate amount of CO2 of 11.9%?
Answer
  • to provide a safety margin
  • to provide a higher efficiency
  • to maintain a neutral pressure point at the door catch
  • to maintain a low stack temperature

Question 61

Question
Net stack temperature is the flue gas temperature:
Answer
  • downstream of the draft hood
  • upstream of the draft hood
  • plus the ambient temperature
  • minus the ambient temperature

Question 62

Question
A forced draft burner has a blower that produces sufficient pressure to overcome the resistance of the:
Answer
  • burner
  • burner and the appliance
  • burner and the appliance downdraft
  • venting system

Question 63

Question
When the installation of an appliance constitutes a conversion from another form of energy to gas, the installer must:
Answer
  • advise the user in writing of the procedure to follow to discontinue the supply of the former form of energy
  • remove all aspects of the previous installation
  • remove the electrical supply wiring from the panel
  • advise the previous energy supplier of the change

Question 64

Question
When the required minimum clearance for a vent connector is 9” (228 mm) to combustible material with no protection, what is the acceptable method to reduce the clearance by 3” (76 mm)?
Answer
  • use 0.05” (12 mm) insulating millboard spaced out 0.05 (12 mm) with noncombustible spacers
  • use 0.25” (6 mm) insulating millboard spaced out 1” (25 mm)
  • use 22 gauge sheet metal attached to the hot side of the-combustible material
  • use 28 gauge sheet metal spaced out 1” (25 mm) from the combustible material

Question 65

Question
What will happen when the neutral pressure point for a conversion burner is improperly set?
Answer
  • the unit will overfire
  • the burner will short cycle
  • the burner efficiency will be affected
  • the burner will not fire

Question 66

Question
Gross stack temperature is the flue gas temperature
Answer
  • downstream of the draft hood
  • upstream of the draft hood
  • plus the ambient temperature
  • minus the ambient temperature

Question 67

Question
When using a gas detector such as a Drager or Gas Tec type, the most important aspect regarding the sample tube is that the:
Answer
  • detector is within the manufacturer’s date code
  • sample tube is within the manufacturer’s date code
  • detector has been inspected and verified
  • the sample tube is CGA approved

Question 68

Question
What is the minimum service clearance in front of a boiler?
Answer
  • 18” (450 mm)
  • 24” (600 mm)
  • 36” (900 mm)
  • 48” (1200 mm)

Question 69

Question
The high limit setting on a forced warm air converted furnace shall not exceed:
Answer
  • 150°F (66°C)
  • 200°F (90°C)
  • 250°F (120°C)
  • 350°F (180°C)

Question 70

Question
Increasing the burners air supply will have the following effect on the percentage of CO2 in the flue gases and stack temperature:
Answer
  • the percentage of CO2 will increase and the stack temperature will increase
  • the percentage of CO2 will decrease and the stack temperature will increase
  • the percentage of CO2 will decrease and the stack temperature will decrease
  • the percentage of CO2 will increase and the stack temperature will decrease

Question 71

Question
What is the minimum clearance to combustibles from the top of the plenum of a converted forced warm air furnace?
Answer
  • 1” (25 mm)
  • 3” (75 mm)
  • 6” (150 mm)
  • 12” (300 mm)

Question 72

Question
When using a flue gas analyzer, which measures CO2 and you are in doubt as to the accuracy of the reading, how would you verify the accuracy of the instrument?
Answer
  • by comparing it to a second sample
  • by comparing it to a known sample
  • by checking it against a gas meter test dial
  • by checking it against the appliance manufacturers maximum input rating

Question 73

Question
How far above the burner port does the centre line of the flue outlet have to be to convert a revertible flue furnace with a natural draft burner?
Answer
  • at least 6” (150 mm)
  • less than 12” (300 mm)
  • at least 12” (300 mm)
  • at least 24” (600 mm)

Question 74

Question
What will be the result if too large a fire pot is used in a converted furnace or boiler?
Answer
  • pulsation will occur
  • there will be poor efficiency
  • the limit control will be ineffective
  • the high limit switch will open

Question 75

Question
What is the minimum clearance to combustibles material from the sides of a converted boiler?
Answer
  • 3” (75 mm)
  • 6” (150 mm)
  • 12” (300 mm)
  • 18” (450 mm)

Question 76

Question
What should be done if a relief valve is leaking?
Answer
  • remove the valve and clean off the calcium deposits
  • replace the valve seat and check for the cause of the activation
  • replace the relief valve and check for the cause of the activation
  • open a tap and relieve the tank pressure until the flow stops at the relief valve

Question 77

Question
What is the pressure relief valve setting for most residential type water heaters?
Answer
  • 75 psig (517 kPa)
  • 100 psig (690 kPa)
  • 150 psig (1034 kPa)
  • 200 psig (1380 kPa)

Question 78

Question
From the following list, which is the best location for a combination heating system consisting of a water heater and air handler?
Answer
  • in the insulated but unheated attached garage
  • the water heater in the basement and the air handler in the attic
  • together in a central location in the basement
  • the air handler supported on top of a rear flue water heater in a closet space

Question 79

Question
Which of the controls listed below controls the gas pressure to the main burner, the temperature of the water, and turns off the gas when the pilot goes out?
Answer
  • E.C.O.
  • temperature and pressure relief valve
  • aquastat
  • unitrol

Question 80

Question
Combination systems are sized to deliver __________ of the calculated heat loss of the building.
Answer
  • 90%
  • 95% to 105%
  • 120%
  • 200%

Question 81

Question
The recommended water temperature setting from a mixing valve to the domestic water system in combination heating systems that employ oil-fired water heaters for heating potable water and for space heating is:
Answer
  • 43°C (110°F)
  • 49°C to 54°C (120°F to 130°F)
  • 60°C to 66°C (140°F to 150°F)
  • 83°C (180°F)

Question 82

Question
The components of a copper fin tube, instantaneous water heater are a/an:
Answer
  • anti-scald device and a pump control
  • pump, pump control, flow switch, temperature/pressure relief valve, and a limit control
  • E.C.O., temperature and pressure relief valve, anode, and a dip tube
  • temperature and pressure relief valve, anode, and a limit control

Question 83

Question
The temperature of the water returning from the heating loop in a combination system employing a water heater for domestic hot water and space heating must be:
Answer
  • higher than the outlet temperature from the water heater
  • no more than 5°C (9°F) below the outlet temperature from the water heater
  • lower than the minimum temperature required to activate the burner
  • at least the set temperature of the domestic hot water supply

Question 84

Question
Describe the leak testing required when replacing an existing gas water heater.
Answer
  • soap or detection instrument using an inert gas using table 8.25.2 to determine test pressure and duration
  • soap or detection instrument at the normal working pressure
  • soap or detection instrument at 2 times the normal working pressure
  • soap or detection instrument and a 10 minute dial test or leak test at normal working pressure

Question 85

Question
The flow rate of water passing through a heating coil of an air handler is controlled by the:
Answer
  • aquastat on the water heater
  • balancing valve on the heating loop
  • mixing valve on the heating loop
  • mixing valve on the domestic hot water system

Question 86

Question
What will cause the E.C.O. to open?
Answer
  • a defective thermostat
  • long draws of water
  • a dip tube which is too short
  • too low a thermostat setting

Question 87

Question
When can combination-heating systems employing a water heater be attached to baseboards or radiators that were previously used for boiler heating?
Answer
  • always
  • never
  • only after being cleaned with muriatic acid
  • only after having been descaled

Question 88

Question
What type of water heater can be installed in a bathroom?
Answer
  • direct vent
  • power vent
  • fan assisted
  • revertible flue

Question 89

Question
What is the minimum required clearance from combustibles to the top, bottom, and sides of a horizontal furnace?
Answer
  • 6”
  • 5”
  • 12”
  • 18”

Question 90

Question
When is it permissible to store propane cylinders in the basement of a new home for future connection to a construction heater?
Answer
  • always
  • never
  • only when the hose is less than 10 feet long
  • only when a flex connector is used

Question 91

Question
Which instrument is used to determine the speed of a direct drive fan motor?
Answer
  • A voltmeter
  • A manometer
  • An anemometer
  • A tachometer

Question 92

Question
Which control will shut the gas flow off in a high efficiency furnace if the venter motor fails?
Answer
  • high limit switch
  • roll out switch
  • air proving switch
  • ignition switch

Question 93

Question
In a repair garage, an appliance shall be installed so that a component capable of igniting a flammable vapour is located at least ______________ above the floor.
Answer
  • 18 inches (450 mm)
  • 2 feet (600 mm)
  • 4.5 feet (1500 mm)
  • 6 feet (2 m)

Question 94

Question
What is the minimum distance that the vent from a 75,000 Btuh Category III furnace may terminate from a door?
Answer
  • 1 foot
  • 3 feet
  • 6 feet
  • 10 feet

Question 95

Question
Before lighting a burner in a steam boiler, ensure that:
Answer
  • there is water in the boiler
  • the temperature controller is set properly
  • the main burner test firing valve is turned on
  • the safety valves are open

Question 96

Question
On seasonal start up, a pool heater should run:
Answer
  • intermittently
  • continuously for 24 hours
  • continuously until the thermostat is satisfied
  • one hour on and one hour off until the thermostat is satisfied

Question 97

Question
Automatic chlorinators must be installed:
Answer
  • upstream of the heater
  • downstream of the heater
  • upstream of the filter
  • downstream of the filter

Question 98

Question
If the thermostat heat anticipator is set to too low a setting:
Answer
  • the space temperature will be too high
  • the space temperature will be too low
  • the burner will run until the desired space temperature is achieved
  • the circulating pump will run continuously

Question 99

Question
Aquastats respond to changes in:
Answer
  • flue gas temperature
  • water temperature
  • stack temperature
  • air temperature

Question 100

Question
The external bypass valve is set by:
Answer
  • shutting off the pump
  • viewing the burner flame size
  • determining the appliance input
  • determining the temperature rise across the appliance

Question 101

Question
What safety control protects a steam boiler if the condensate pump fails to return water to the boiler?
Answer
  • high pressure limit control
  • low pressure limit control
  • flame safeguard control
  • low water cutoff

Question 102

Question
Condensate in a boiler heating system is:
Answer
  • water heated for use in restaurant equipment
  • water in a water boiler return line
  • water from the relief valve in a boiler
  • water in a steam boiler return line

Question 103

Question
A room heater installed in either a sleeping area or public area shall be:
Answer
  • direct vent only
  • equipped with a regulator
  • equipped with a fan
  • equipped with an on / off switch on the wall

Question 104

Question
Single wall vent connectors:
Answer
  • may pass through floors, ceilings or roofs provided a metal thimble is used
  • may pass through floors, ceilings or roofs provided the required minimum distance from combustible material is maintained
  • may pass through floors, ceilings or roofs provided they are insulated
  • shall not pass through floors, ceilings or roofs

Question 105

Question
An appliance vent shall terminate from any building mechanical air inlet by at least:
Answer
  • 1 foot (300 mm)
  • 3 feet (900 mm)
  • 6 feet (1800 mm)
  • 10 feet (3 m)

Question 106

Question
What material must be used for the vent connector on an appliance without flue gas dilution air?
Answer
  • 22 B & SG (0.64 mm) aluminum
  • 24 GSG (0.60 mm) galvanized steel
  • 26 GSG (0.47 mm) galvanized steel
  • 28 GSG (0.38 mm) galvanized steel

Question 107

Question
Which of the following statements is correct?
Answer
  • a draft hood will eliminate back drafts coming down the chimney
  • a draft hood will prevent a negative pressure inside the building
  • a draft hood will prevent a down draft from entering the appliance
  • a draft hood will prevent flue gases from entering a building

Question 108

Question
The function of a fixed draft hood is to ensure:
Answer
  • negative over fire draft
  • positive over fire draft
  • zero (neutral) over fire draft
  • variable over fire draft condition

Question 109

Question
When sizing either a vent or chimney which will vent more than one natural gas appliance, which of the following could be used in determining the size of the common vent?
Answer
  • the area of the common vent shall equal the total area of all the flue collars
  • the area of the common vent shall equal the area of the largest single flue collar
  • the area of the common vent shall equal the area of either the largest draft control device outlet or the largest flue outlet plus 50% of the sum of the outlet areas of the additional appliances
  • the area of the common vent shall equal the area of either the largest draft control device outlet or the largest flue outlet plus 75% of the sum of the outlet areas of the additional appliances

Question 110

Question
There is a new forced air furnace equipped with an induced draft fan beside a conventional water heater in a basement. The customer has decided to enclose the area to make a separate furnace room. The house is approximately 25 years old and has a door separating the basement from the upper levels. 

- Furnace input = 100,000 Btuh (8.1.2 and footnote)
 - AWH input = 25,000 Btuh 
- Enclosure = 10’ x 20’ x 7’
 - Structure dimensions = 20’ x 30’ x 7’ x 3 (levels) 

What size opening will be required in the furnace room door to provide sufficient combustion air from inside the home?
Answer
  • 0 square inches
  • 9 square inches
  • 18 square inches
  • 125 square inches

Question 111

Question
There is a new forced air furnace equipped with an induced draft fan beside a conventional water heater in a basement. The customer has decided to enclose the area to make a separate furnace room. The house is approximately 25 years old and has a door separating the basement from the upper levels. 

- Furnace input = 100,000 Btuh (8.1.2 and footnote)
 - AWH input = 25,000 Btuh 
- Enclosure = 10’ x 20’ x 7’
 - Structure dimensions = 20’ x 30’ x 7’ x 3 (levels) What size opening is required in the furnace room door to provide sufficient ventilation air for the furnace room?
Answer
  • 0 square inches
  • 8 square inches
  • 18 square inches
  • 125 square inches

Question 112

Question
Ventilation air openings for gas appliances should be located:
Answer
  • at the lowest possible point communicating with the outdoors
  • at the highest possible point communicating with the outdoors
  • on the same horizontal plane as the combustion air opening
  • at or above the level of the burner

Question 113

Question
A draft hood for an appliance shall be:
Answer
  • located in a different room than the appliance it serves
  • located in the same room as the appliance it serves
  • installed on an appliance with an induced draft
  • sized to the existing vent connection

Question 114

Question
“Spillage” of flue gases at the appliance draft diverter would indicate that:
Answer
  • an updraft condition is present in the venting system of the appliance
  • there is excessive draft at the appliance
  • the venting system of the appliance is restricted
  • the appliance is under fired

Question 115

Question
A boiler room contains the following natural draft appliances:

 - two hot water boilers, each firing at 750,000 Btuh 
- 1 water heater firing at 270,000 Btuh
 - 1 water heater firing at 30,000 Btuh

 What is the minimum required combustion air opening?
Answer
  • 100 square inches
  • 200 square inches
  • 900 square inches
  • 1800 square inches

Question 116

Question
What is the minimum size required for the air supply opening given the information listed below?

 All appliances are equipped with draft diverters, the building is of recent construction with close fitting windows and doors, vapour barrier and drywall and the total input of all appliances is 310,000 Btuh.
Answer
  • 36 square inches (23000 mm2)
  • 43 square inches (28000 mm2)
  • 47 square inches (30000 mm2)
  • 50 square inches (32000 mm2)

Question 117

Question
Which of the following instruments is used to check the pressure drop across an indoor coil?
Answer
  • a velometer
  • an inclined manometer
  • an anemometer
  • a psychrometer

Question 118

Question
What is the purpose of an air-proving switch in an electronic air cleaner?
Answer
  • it ensures the fan motor is running
  • it ensures the fan is running
  • it ensures the draft is correct
  • it ensures there is no negative air

Question 119

Question
What happens when the humidistat for a power humidifier closes?
Answer
  • the humidifier solenoid valve opens
  • the humidifier motor starts to turn
  • the furnace fan starts, then the humidifier starts
  • the gas valve opens the humidifier starts

Question 120

Question
How are electronic air cleaners wired?
Answer
  • in parallel with the fan motor
  • in series with the fan motor
  • in parallel with the fan
  • in series with the fan

Question 121

Question
Why is it important to position an electronic air cleaner correctly?
Answer
  • to ensure as much of the air is bypassed as is possible
  • to remove as many odours as possible
  • to ensure there is as much restriction to air flow as possible
  • to ensure an even distribution of air across the face of the filter

Question 122

Question
Plate humidifiers operate:
Answer
  • all the time the fan is running
  • only when the fan is on low speed
  • only when the fan is on high speed
  • only when the humidistat calls

Question 123

Question
The primary voltage for duct mounted electronic air cleaners is:
Answer
  • 20 – 30 volts
  • 120 – 130 volts
  • 220 – 240 volts
  • 9,000 – 12,000 volts

Question 124

Question
What is the most common transformer required for a power humidifier?
Answer
  • 120 – 24 volt
  • 240 - 24 volt
  • 240 – 120 volt
  • 120 – 240 volt

Question 125

Question
Heat which when added to or removed from a substance causes a change of temperature is:
Answer
  • superheat
  • specific heat
  • latent heat
  • sensible heat

Question 126

Question
Which device can be used to determine the restrictions in a duct system?
Answer
  • hydrometer
  • potentiometer
  • barometer
  • manometer

Question 127

Question
If the belt on a blower is too tight, the motor:
Answer
  • voltage will decrease
  • voltage will increase
  • current will decrease
  • current will increase

Question 128

Question
If the fan compartment door of an appliance is left off, the motor:
Answer
  • voltage will decrease
  • voltage will increase
  • current will decrease
  • current will increase

Question 129

Question
Where is the lowest air pressure in a forced warm air heating system?
Answer
  • in all ductwork
  • upstream of the blower
  • downstream of the blower
  • at the supply registers

Question 130

Question
Convection is:
Answer
  • heat transfer through solid objects
  • heat transfer through fluids
  • a wave form of heat transfer
  • a form of latent heat transfer

Question 131

Question
Increasing the size of a blower pulley:
Answer
  • increases air flow
  • decreases air flow
  • increases current flow
  • decreases temperature rise

Question 132

Question
A fan control:
Answer
  • shuts the blower off on safety only
  • starts the blower when the plenum is up to temperature
  • starts and stops the blower
  • ensures the burner will not start if overheating occurs

Question 133

Question
What is the minimum diameter of a pressure gauge needed to perform a leak test on gas piping?
Answer
  • 2 in.
  • 2 – 3/4 in.
  • 3 in
  • 3 – 1/2 in.

Question 134

Question
Ammeter’s can read what?
Answer
  • Pressure drop
  • Conductor magnetic field
  • Load in parallel wires
  • Direct power across loads

Question 135

Question
What are the millivolts power output on a closed circuit test?
Answer
  • 20 to 30 mV
  • 10 to 15 mV
  • 2 to 4 mV
  • 10 mV or less

Question 136

Question
A pilot with a lazy yellow flame would indicate?
Answer
  • Orifice too small
  • Mid to high gas pressure
  • Target pilot orifice
  • Orifice size too large

Question 137

Question
For flame rectification one of the most important things should be?
Answer
  • Flame molecules
  • Proper grounding plane
  • Proper air to gas mixture to pilot
  • Flame rod insulator

Question 138

Question
What makes a flame capillary sensor tube prove pilot to main gas valve?
Answer
  • Trial for ignition
  • Glow coil
  • Pilot flame
  • Intermittent pilot

Question 139

Question
Can a new installation of a fin type pool heater less than 250 MBtu be installed downstairs in a house?
Answer
  • Yes, if gas piping can support gas input
  • No
  • Yes, if pool heater is direct vented
  • Yes, if poll heater is close to chimney

Question 140

Question
When converting an oil furnace to gas what type of atmospheric burner can be used?
Answer
  • Burner tray
  • In shot
  • Ribbon burner
  • Primary air fan assist burner

Question 141

Question
If the flue gases are removed from the front of the appliance we could assume that it's a?
Answer
  • 1 to 3 flue pass boiler
  • 2 to 6 flue pass boiler
  • 2 to 5 flue pass boiler
  • 2 to 4 flue pass boiler

Question 142

Question
Can a gas log fireplace be installed in a sleeping quarter?
Answer
  • Yes, if proper air supply is added
  • Yes, if the venting is over sized
  • No, even if new venting is installed
  • Yes, only if its a bed sitting room

Question 143

Question
What is the minimum distance that a vent from an appliance with an input of 110 Mbtu/h can be from a non-mechanical air supply?
Answer
  • 1 ft.
  • 2 ft.
  • 3 ft
  • 6 ft.

Question 144

Question
On a pressuretrol, the main burner starts on?
Answer
  • Pressure rise
  • Water level
  • Pressure differential
  • Steam system output

Question 145

Question
On a hydronic heater system what control responds to a load change?
Answer
  • Low water cut off
  • Expansion tank
  • Flow switch
  • Aquastat

Question 146

Question
When installing propane tanks under 1,000 USWG, what would be the minimum distance from a building?
Answer
  • 25 ft.
  • 30 ft.
  • 15 ft.
  • 10 ft.

Question 147

Question
If an appliance is less than 83% efficient and non-positive it would be considered a?
Answer
  • Category II
  • Category I
  • Category IV
  • Category III

Question 148

Question
For a steam boiler, what would be the most important safety control?
Answer
  • Flame scanner
  • Flame roll out switch
  • Low water cut off
  • High limit steam lock out control

Question 149

Question
For a low-pressure steam boiler what would be the maximum steam pressure setting?
Answer
  • 30 psig
  • 25 psig
  • 10 psig
  • 15 psig

Question 150

Question
How would you measure relative humidity?
Answer
  • Wet bulb and atmospheric pressure
  • Dry bulb and latent heat of vapour
  • Moisture bulb and wet bulb
  • Wet bulb and dry bulb

Question 151

Question
What is nitrogen known as?
Answer
  • Toxins
  • Explosive gases
  • Inert gas
  • Neutralizers

Question 152

Question
Which heat is removed or added to cause a change in state without change in temperature?
Answer
  • Sensible heat
  • Radiant heat
  • Latent heat
  • Super heat

Question 153

Question
Except when permitted, what is the minimum clearance to combustibles from the top of a gas refrigerator?
Answer
  • 2 in.
  • 10 in.
  • 36 in.
  • 12 in

Question 154

Question
On a gas regulator, what controls the increase or decrease of gas flow to the appliance?
Answer
  • Restricting element
  • Vent hold
  • Loading element
  • Measuring element

Question 155

Question
When sizing capacitors in series, what would be the total capacitance (CT) using 12F and 15F capacitors?
Answer
  • 5.66 CT
  • 6.35 CT
  • 6.97 CT
  • 6.66 CT

Question 156

Question
What would be the Btu/h output of a 10 kW heater
Answer
  • 38,210 Btu/h
  • 36,220 Btu/h
  • 33,150 Btu/h
  • 34,120 Btu/h

Question 157

Question
Clocking a 5 cu ft. dial on a gas meter for 63 seconds, what would be the appliance input?
Answer
  • 258 MBtu/h
  • 286 MBtu/h
  • 268 MBtu/h
  • 284 MBtu/h

Question 158

Question
What does a gas pressure regulator control?
Answer
  • Inlet pressure
  • Gas flow
  • Downstream pressure
  • Locks out gas flow

Question 159

Question
A first stage or high-pressure regulator reduces tank pressure to...?
Answer
  • 350 Psig to 10 Psig
  • 375 Psig to 5 Psig
  • 250 Psig to 10 Psig
  • 375 Psig to 10 Psig

Question 160

Question
On a regulator, what senses outlet pressure?
Answer
  • Restricting element
  • Measuring element
  • Loading element
  • Spring element

Question 161

Question
Which gas meter would be used for a small or mid size commercial installation?
Answer
  • Rotary type
  • Tubing type
  • Bellows type
  • Orifice

Question 162

Question
A bellows gas meter is also known as a?
Answer
  • Down stream displacement meter
  • Up stream displacement meter
  • Pressure displacement meter
  • Positive displacement meter

Question 163

Question
A fan assist burner is?
Answer
  • Designed for better combustion
  • Designed for conversion boiler
  • Designed to overcome appliance friction
  • Designed to overcome burner resistance

Question 164

Question
A propane service regulator would normally deliver pressure at
Answer
  • Pound to 11 in. w.c.
  • Ounces to 7 in. w.c.
  • Ounces to 11 in. w.c.
  • Pound to 7 in. w.c.

Question 165

Question
What monitors water flow in a pool heater?
Answer
  • Aquastat
  • Low water cut off
  • Pressure switch
  • Flow switch

Question 166

Question
On a gas regulator, what is used to adjusts the outlet pressure?
Answer
  • Restricting element
  • Loading element
  • Limiting orifice
  • Measuring element

Question 167

Question
Venting spillage can be caused by?
Answer
  • Improper combustion air mixture
  • Excessive elbows in venting system
  • Cracked heat exchanger
  • Blocked condensate furnace drain

Question 168

Question
When vent spillage occurs and flue gases pass back through the combustion zone, what change occurs?
Answer
  • Flue gases are hotter and rise faster through chimney
  • Flue CO2 gases are more efficient
  • Flue CO2 gases changes to N2
  • Flue CO2 gases changes to CO

Question 169

Question
For a freestanding propane range in a large kitchen, the flexible connector may be how long?
Answer
  • 10 ft.
  • 6 ft
  • 4 ft.
  • 8 ft. if range is in the center of the kitchen

Question 170

Question
An inverted sensor (measures water level) can be found operating what type of appliance?
Answer
  • Hot water boiler
  • Steam water boiler
  • Domestic hot water storage tank
  • Domestic potable hot water tank

Question 171

Question
What would be the input of a 0.60-gph-oil nozzle?
Answer
  • 73 MBtu
  • 70 MBtu
  • 84 MBtu
  • 50 MBtu

Question 172

Question
On a high efficiency furnace, what turns on the blower fan?
Answer
  • Klixon limit
  • Bi-metal switch
  • Relay timer
  • Temperature

Question 173

Question
A vent-limiting orifice is only allowed to approximately discharge how much gas in a 24-hour period?
Answer
  • 1 cubic foot
  • 10 cubic feet
  • 20 cubic feet
  • 24 cubic feet

Question 174

Question
What is the ultimate reading of CO2 (carbon dioxide) for natural gas?
Answer
  • 9.9%
  • 10.9%
  • 11.9%
  • 13.9%

Question 175

Question
What would be the approximate O2 (oxygen) reading?
Answer
  • 9.0%
  • 7.0%
  • 5.0%
  • 3.0%

Question 176

Question
What does a barometric damper control?
Answer
  • Excess Air
  • Pilot Air
  • Draft Air
  • Ventilation Air

Question 177

Question
A coil type boiler less than 400 MBtu would need a:
Answer
  • Spill switch and Low water cut off
  • Low water cut off and hi limit
  • Flow sensor and hi limit
  • Spill switch and hi limit

Question 178

Question
A portable infrared heater that cannot be interlocked shall be connected to a:
Answer
  • CO2 monitor alarm
  • CO monitor alarm
  • O2 monitor alarm
  • CO and O2 monitor alarm

Question 179

Question
On a decorative appliance with an H-shape burner, the carry over ports ensures:
Answer
  • Primary air mixture
  • Ignition of entire burner
  • Blue flame
  • Secondary air

Question 180

Question
The temperature of a high intensity infrared heater could reach up to:
Answer
  • 1000°F
  • 1800°F
  • 1200°F
  • 2025°F

Question 181

Question
Stack effect means?
Answer
  • Air flow though the appliance
  • Negative building pressure
  • Warm air will rise
  • External building envelope

Question 182

Question
What could be the problem if a domestic hot water tank dropped in temperature after five minutes of use?
Answer
  • Low gas input
  • Mixing valve
  • Broken dip tube
  • Gas valve

Question 183

Question
What is the minimum location from a property line that a pool heater can be installed?
Answer
  • 24 in.
  • 20 in.
  • 18 in.
  • 12 in.

Question 184

Question
Standard sizing for a circulating pump would be?
Answer
  • 1 gpm per 2,000 Btu
  • 3 gpm per 20,000 Btu
  • 1 gpm per 1,000 Btu
  • 1 gpm per 10,000 Btu

Question 185

Question
If you had a commercial air handler and needed to know the speed of the blower where the pulley on a five-horse power 3,450-rpm motor is 6-inch and the pulley on a two-inch-fifteen-foot drive shaft is 10-inch, what would be the rpm of the blower?
Answer
  • 3450 rpm
  • 2070 rpm
  • 1725 rpm
  • 863 rpm

Question 186

Question
What is the total diameter of a 4L-28 "V" drive belt?
Answer
  • 280 in.
  • 35 in.
  • 28 in.
  • 2.80 in.

Question 187

Question
What is the spark gap required for a spark ignitor?
Answer
  • 1/4 to 3/8 in.
  • 3/8 to 1/2 in.
  • 1/16 to 3/16 in.
  • 1/8 to 3/16 in

Question 188

Question
On a direct spark ignition control, what is the trial for ignition?
Answer
  • 10 seconds
  • 0.8 seconds
  • 4 seconds
  • 2 seconds

Question 189

Question
A pilotstat will de-energize after how many seconds?
Answer
  • 0.8 seconds
  • 10 seconds
  • 90 seconds
  • 4 seconds

Question 190

Question
What does a heat anticipator do?
Answer
  • Shuts the burner down if loss of gas supply
  • Determines the length of the burner "on" cycle
  • Acts as a back up safety limit
  • Shuts down burner on excess flow

Question 191

Question
Can NMD wire be installed to an outside gas lamp?
Answer
  • Yes
  • No
  • Only if the lamp is direct spark
  • Yes if it is 14 AWG wire

Question 192

Question
How many cubic feet of vapor will one pound of liquid propane (C3H8) expand to?
Answer
  • 5.1 cu ft.
  • 8.0 cu ft
  • 7.5 cuft.
  • 8.5 cu ft.

Question 193

Question
What does a spiral baffle do?
Answer
  • Remove flue gas
  • Speed up combustion
  • Slow flue gas
  • Raises flue temperature

Question 194

Question
When converting a furnace, how far above the burner must the flue collar be?
Answer
  • 6 in.
  • 8 in.
  • 10 in.
  • 12 in.

Question 195

Question
What would be the approximate time for purging a 1-inch NPS pipe at 100-feet?
Answer
  • 50 seconds
  • 1 minute
  • 1 minute, 24 seconds
  • 1 minute, 10 seconds

Question 196

Question
Natural gas is mostly made up of?
Answer
  • Methane and Butane
  • Methane and Ethane
  • Ethane and Butane
  • Butane and Propane

Question 197

Question
On a 14 /12 pitch roof, what would be the termination of a 5-inch B-Vent?
Answer
  • 4 ft.
  • 5 ft.
  • 6 ft.
  • 10 ft.

Question 198

Question
For a 20 horsepower steam boiler, what would be its maximum input in Btu?
Answer
  • 200 Mbtu
  • 530 Mbtu
  • 680 Mbtu
  • 700 Mbtu

Question 199

Question
On category IV appliances, can a single wall vent be used to vent flue gases?
Answer
  • Yes
  • No
  • Manufacturer approved only
  • Only if vents are silicone together

Question 200

Question
At what temperature do flue gases condensate?
Answer
  • 125°F
  • 127°F
  • 129°F
  • 130°F
Show full summary Hide full summary

1 comment

Chris Grompson
Chris Grompson
over 2 years ago (edited)
There are a few errors... gross stack temp is measured upstream or draft hood adjusting regulator will change pressure downstream not upstream code clause dealing with zero clearance ranges has been revoked heater in a public area or sleeping area must have a regulator .... there are more

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