G2 EXAM part 1

Descrição

Quiz sobre G2 EXAM part 1, criado por toan nguyen em 08-02-2022.
toan nguyen
Quiz por toan nguyen, atualizado more than 1 year ago
toan nguyen
Criado por toan nguyen mais de 4 anos atrás
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Resumo de Recurso

Questão 1

Questão
Schedule 80 pipe is required in a propane system:
Responda
  • 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

Questão 2

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

Questão 3

Questão
Natural gas piping in industrial buildings shall be identified:
Responda
  • 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

Questão 4

Questão
A panel-mounted ground fault circuit interrupting breaker protects all:
Responda
  • 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

Questão 5

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

Questão 6

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

Questão 7

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

Questão 8

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


Questão 9

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

Questão 10

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

Questão 11

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

Questão 12

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

Questão 13

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

Questão 14

Questão
On an electrical schematic, the system is shown with the:
Responda
  • 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

Questão 15

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

Questão 16

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

Questão 17

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

Questão 18

Questão
When can an on/off switch be installed in the neutral wire from an electrical panel to a gas furnace:
Responda
  • 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

Questão 19

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

Questão 20

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

Questão 21

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

Questão 22

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

Questão 23

Questão
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?
Responda
  • 3/32” (2 mm)
  • 1/8” (3 mm)
  • 1/4” (6 mm)
  • 1/2" (12 mm)

Questão 24

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

Questão 25

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

Questão 26

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

Questão 27

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

Questão 28

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

Questão 29

Questão
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?
Responda
  • 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

Questão 30

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

Questão 31

Questão
From the following list, which action will have the greatest effect on reducing mold growth in the house?
Responda
  • 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

Questão 32

Questão
Which of the following actions will limit the problems caused by the “distribution effect” on conventional vented forced air furnaces?
Responda
  • 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

Questão 33

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

Questão 34

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

Questão 35

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

Questão 36

Questão
Which symbol represents a gas solenoid?
Responda
  • 4
  • 5
  • 6
  • 7

Questão 37

Questão
Which symbol represents the dryer heat thermostat?
Responda
  • 1
  • 2
  • 3
  • 4

Questão 38

Questão
Which symbol represents a dryer high limit switch?
Responda
  • 1
  • 3
  • 4
  • 7

Questão 39

Questão
Which symbol represents a dryer centrifugal switch?
Responda
  • 1
  • 4
  • 6
  • 7

Questão 40

Questão
Which symbol represents a dryer pilot switch?
Responda
  • 1
  • 2
  • 3
  • 7

Questão 41

Questão
Which symbol represents a timer motor?
Responda
  • 4
  • 5
  • 6
  • 7

Questão 42

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

Questão 43

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

Questão 44

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

Questão 45

Questão
What type of protection does a range require if it is certified for zero side clearance from combustible material?
Responda
  • 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

Questão 46

Questão
The primary function of a surge arrestor in the top of a regulator is to:
Responda
  • 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

Questão 47

Questão
Propane containers located on the outside of a recreational vehicle shall be:
Responda
  • 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

Questão 48

Questão
A monitor regulator:
Responda
  • 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

Questão 49

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

Questão 50

Questão
For appliances with the same input, the size of the orifice used for a propane appliance should be:
Responda
  • 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

Questão 51

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

Questão 52

Questão
What should be done if it is noticed that a regulator set in a loading dock area is not protected against physical damage?
Responda
  • 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

Questão 53

Questão
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)
Responda
  • 42%
  • 60%
  • 80%
  • 90%

Questão 54

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

Questão 55

Questão
A regulator is sized for the load it is to serve by:
Responda
  • 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

Questão 56

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

Questão 57

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

Questão 58

Questão
Is it permissible to use the propane side of a refrigerator in a recreation vehicle while the vehicle is in motion?
Responda
  • 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

Questão 59

Questão
How can the location of a leak in a heat exchanger be determined?
Responda
  • 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

Questão 60

Questão
Why does the recommended range of CO2 in a conventional furnace differ from the ultimate amount of CO2 of 11.9%?
Responda
  • 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

Questão 61

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

Questão 62

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

Questão 63

Questão
When the installation of an appliance constitutes a conversion from another form of energy to gas, the installer must:
Responda
  • 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

Questão 64

Questão
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)?
Responda
  • 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

Questão 65

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

Questão 66

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

Questão 67

Questão
When using a gas detector such as a Drager or Gas Tec type, the most important aspect regarding the sample tube is that the:
Responda
  • 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

Questão 68

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

Questão 69

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

Questão 70

Questão
Increasing the burners air supply will have the following effect on the percentage of CO2 in the flue gases and stack temperature:
Responda
  • 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

Questão 71

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

Questão 72

Questão
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?
Responda
  • 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

Questão 73

Questão
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?
Responda
  • at least 6” (150 mm)
  • less than 12” (300 mm)
  • at least 12” (300 mm)
  • at least 24” (600 mm)

Questão 74

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

Questão 75

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

Questão 76

Questão
What should be done if a relief valve is leaking?
Responda
  • 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

Questão 77

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

Questão 78

Questão
From the following list, which is the best location for a combination heating system consisting of a water heater and air handler?
Responda
  • 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

Questão 79

Questão
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?
Responda
  • E.C.O.
  • temperature and pressure relief valve
  • aquastat
  • unitrol

Questão 80

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

Questão 81

Questão
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:
Responda
  • 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)

Questão 82

Questão
The components of a copper fin tube, instantaneous water heater are a/an:
Responda
  • 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

Questão 83

Questão
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:
Responda
  • 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

Questão 84

Questão
Describe the leak testing required when replacing an existing gas water heater.
Responda
  • 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

Questão 85

Questão
The flow rate of water passing through a heating coil of an air handler is controlled by the:
Responda
  • 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

Questão 86

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

Questão 87

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

Questão 88

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

Questão 89

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

Questão 90

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

Questão 91

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

Questão 92

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

Questão 93

Questão
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.
Responda
  • 18 inches (450 mm)
  • 2 feet (600 mm)
  • 4.5 feet (1500 mm)
  • 6 feet (2 m)

Questão 94

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

Questão 95

Questão
Before lighting a burner in a steam boiler, ensure that:
Responda
  • 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

Questão 96

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

Questão 97

Questão
Automatic chlorinators must be installed:
Responda
  • upstream of the heater
  • downstream of the heater
  • upstream of the filter
  • downstream of the filter

Questão 98

Questão
If the thermostat heat anticipator is set to too low a setting:
Responda
  • 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

Questão 99

Questão
Aquastats respond to changes in:
Responda
  • flue gas temperature
  • water temperature
  • stack temperature
  • air temperature

Questão 100

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

Questão 101

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

Questão 102

Questão
Condensate in a boiler heating system is:
Responda
  • 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

Questão 103

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

Questão 104

Questão
Single wall vent connectors:
Responda
  • 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

Questão 105

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

Questão 106

Questão
What material must be used for the vent connector on an appliance without flue gas dilution air?
Responda
  • 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

Questão 107

Questão
Which of the following statements is correct?
Responda
  • 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

Questão 108

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

Questão 109

Questão
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?
Responda
  • 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

Questão 110

Questão
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?
Responda
  • 0 square inches
  • 9 square inches
  • 18 square inches
  • 125 square inches

Questão 111

Questão
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?
Responda
  • 0 square inches
  • 8 square inches
  • 18 square inches
  • 125 square inches

Questão 112

Questão
Ventilation air openings for gas appliances should be located:
Responda
  • 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

Questão 113

Questão
A draft hood for an appliance shall be:
Responda
  • 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

Questão 114

Questão
“Spillage” of flue gases at the appliance draft diverter would indicate that:
Responda
  • 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

Questão 115

Questão
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?
Responda
  • 100 square inches
  • 200 square inches
  • 900 square inches
  • 1800 square inches

Questão 116

Questão
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.
Responda
  • 36 square inches (23000 mm2)
  • 43 square inches (28000 mm2)
  • 47 square inches (30000 mm2)
  • 50 square inches (32000 mm2)

Questão 117

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

Questão 118

Questão
What is the purpose of an air-proving switch in an electronic air cleaner?
Responda
  • 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

Questão 119

Questão
What happens when the humidistat for a power humidifier closes?
Responda
  • 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

Questão 120

Questão
How are electronic air cleaners wired?
Responda
  • in parallel with the fan motor
  • in series with the fan motor
  • in parallel with the fan
  • in series with the fan

Questão 121

Questão
Why is it important to position an electronic air cleaner correctly?
Responda
  • 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

Questão 122

Questão
Plate humidifiers operate:
Responda
  • 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

Questão 123

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

Questão 124

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

Questão 125

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

Questão 126

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

Questão 127

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

Questão 128

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

Questão 129

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

Questão 130

Questão
Convection is:
Responda
  • heat transfer through solid objects
  • heat transfer through fluids
  • a wave form of heat transfer
  • a form of latent heat transfer

Questão 131

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

Questão 132

Questão
A fan control:
Responda
  • 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

Questão 133

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

Questão 134

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

Questão 135

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

Questão 136

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

Questão 137

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

Questão 138

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

Questão 139

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

Questão 140

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

Questão 141

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

Questão 142

Questão
Can a gas log fireplace be installed in a sleeping quarter?
Responda
  • 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

Questão 143

Questão
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?
Responda
  • 1 ft.
  • 2 ft.
  • 3 ft
  • 6 ft.

Questão 144

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

Questão 145

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

Questão 146

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

Questão 147

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

Questão 148

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

Questão 149

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

Questão 150

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

Questão 151

Questão
What is nitrogen known as?
Responda
  • Toxins
  • Explosive gases
  • Inert gas
  • Neutralizers

Questão 152

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

Questão 153

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

Questão 154

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

Questão 155

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

Questão 156

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

Questão 157

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

Questão 158

Questão
What does a gas pressure regulator control?
Responda
  • Inlet pressure
  • Gas flow
  • Downstream pressure
  • Locks out gas flow

Questão 159

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

Questão 160

Questão
On a regulator, what senses outlet pressure?
Responda
  • Restricting element
  • Measuring element
  • Loading element
  • Spring element

Questão 161

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

Questão 162

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

Questão 163

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

Questão 164

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

Questão 165

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

Questão 166

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

Questão 167

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

Questão 168

Questão
When vent spillage occurs and flue gases pass back through the combustion zone, what change occurs?
Responda
  • 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

Questão 169

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

Questão 170

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

Questão 171

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

Questão 172

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

Questão 173

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

Questão 174

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

Questão 175

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

Questão 176

Questão
What does a barometric damper control?
Responda
  • Excess Air
  • Pilot Air
  • Draft Air
  • Ventilation Air

Questão 177

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

Questão 178

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

Questão 179

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

Questão 180

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

Questão 181

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

Questão 182

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

Questão 183

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

Questão 184

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

Questão 185

Questão
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?
Responda
  • 3450 rpm
  • 2070 rpm
  • 1725 rpm
  • 863 rpm

Questão 186

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

Questão 187

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

Questão 188

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

Questão 189

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

Questão 190

Questão
What does a heat anticipator do?
Responda
  • 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

Questão 191

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

Questão 192

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

Questão 193

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

Questão 194

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

Questão 195

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

Questão 196

Questão
Natural gas is mostly made up of?
Responda
  • Methane and Butane
  • Methane and Ethane
  • Ethane and Butane
  • Butane and Propane

Questão 197

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

Questão 198

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

Questão 199

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

Questão 200

Questão
At what temperature do flue gases condensate?
Responda
  • 125°F
  • 127°F
  • 129°F
  • 130°F