©BRIGHTSTARS EXAM SOLUTIONS
10/21/2024 9:24 PM
CDC 3E151 - HVAC/R JOURNEYMAN
VOLUME 1 Exam Questions And Answers
100% Pass
(001) When using a halide leak detector, the bluish flame turning green indicates - answer✔a
refrigerant leak
(001) On a manifold gauge assembly, the vacuum hose is 3/8 inch and the other hoses are 1/4
inch because larger sizes allow for - answer✔fewer restrictions which makes it easier and
quicker to pull a vacuum
(001) Why should the manifold gauge assembly not be used when measuring a vacuum? -
answer✔The gauge assembly reads inches of mercury and is not accurate when pulling deep
vacuums
(002) While taking a reading with an infrared thermometer, what happens as you get further from
the object being measured? - answer✔The reading becomes more inaccurate
(003) What part of the combustion analyzer gets placed into the stack? - answer✔The probe
(003) What transfers flue gases from the boiler stack to the indicator unit? - answer✔A tube and
hand bulb
(003) The special slide-rule calculator and CO2 indicator are used to determine -
answer✔combustion efficiency and stack loss
(004) What will occur if you choose more than one conductor to measure when using a clamp on
meter? - answer✔Incorrect readings
(004) A megohmmeter should never be used on a live circuit because - answer✔it has its own
power source and it will ruin the meter
(004) A capacitance checker is used to test - answer✔a capacitor
, ©BRIGHTSTARS EXAM SOLUTIONS
10/21/2024 9:24 PM
(005) A photo tachometer is used to read the - answer✔revolutions per minute (RPM) of a
spinning motor shaft
(005) When using a stroboscope, the frequency and reading is displayed for the technician when
the object appears to be - answer✔standing still and the rpm of the equipment matches
(005) What pressure will be given if both tubes are connected to the inclined manometer? -
answer✔Velocity pressure
(005) Magnehelic pressure gauges were developed to - answer✔overcome the disadvantages of
the inclined and the inclined vertical manometers
Why does the magnehelic gauge need more frequent calibration? - answer✔Because it is a
mechanical instrument and is sensitive to physical abuse, dirt, dust, corrosive gases, and fluids
(005) Why is the accuracy at filters, louvers, and coils very rough? - answer✔Due to the
uncertainty of the Ak ( correction factor) area
(005) In order to be measured by the flow hood, how is all of the air forced to flow through the
diffuser or grille? - answer✔A flow hood or capture box completely surrounds and covers a
diffuser or grille
(005) When are flow hoods especially practical? - answer✔In existing buildings where the
manufacturers or Ak factors of the outlets are not known
(005) If you need a tool that functions as a balancing flowmeter you should select - answer✔a
circuit tester
(006) When pipe is needed for a high pressure application you should select - answer✔extra
strong pipe
(006) Pipe should not be threaded when it is - answer✔a wall thickness less than standard weight
(006) When would flanges be installed? - answer✔Wherever it may be necessary to open the
joint for service or replacement of components
(007) What must be done before you apply pressure on the dies? - answer✔Be sure you have the
oil running to help start the segments on the pipe
(007) How are the die segments released? - answer✔Release lever
(008)After you clean the threads of the fitting with a wire brush, what is the next step? -
answer✔Apply a small amount of pipe joint compound to the male threads
10/21/2024 9:24 PM
CDC 3E151 - HVAC/R JOURNEYMAN
VOLUME 1 Exam Questions And Answers
100% Pass
(001) When using a halide leak detector, the bluish flame turning green indicates - answer✔a
refrigerant leak
(001) On a manifold gauge assembly, the vacuum hose is 3/8 inch and the other hoses are 1/4
inch because larger sizes allow for - answer✔fewer restrictions which makes it easier and
quicker to pull a vacuum
(001) Why should the manifold gauge assembly not be used when measuring a vacuum? -
answer✔The gauge assembly reads inches of mercury and is not accurate when pulling deep
vacuums
(002) While taking a reading with an infrared thermometer, what happens as you get further from
the object being measured? - answer✔The reading becomes more inaccurate
(003) What part of the combustion analyzer gets placed into the stack? - answer✔The probe
(003) What transfers flue gases from the boiler stack to the indicator unit? - answer✔A tube and
hand bulb
(003) The special slide-rule calculator and CO2 indicator are used to determine -
answer✔combustion efficiency and stack loss
(004) What will occur if you choose more than one conductor to measure when using a clamp on
meter? - answer✔Incorrect readings
(004) A megohmmeter should never be used on a live circuit because - answer✔it has its own
power source and it will ruin the meter
(004) A capacitance checker is used to test - answer✔a capacitor
, ©BRIGHTSTARS EXAM SOLUTIONS
10/21/2024 9:24 PM
(005) A photo tachometer is used to read the - answer✔revolutions per minute (RPM) of a
spinning motor shaft
(005) When using a stroboscope, the frequency and reading is displayed for the technician when
the object appears to be - answer✔standing still and the rpm of the equipment matches
(005) What pressure will be given if both tubes are connected to the inclined manometer? -
answer✔Velocity pressure
(005) Magnehelic pressure gauges were developed to - answer✔overcome the disadvantages of
the inclined and the inclined vertical manometers
Why does the magnehelic gauge need more frequent calibration? - answer✔Because it is a
mechanical instrument and is sensitive to physical abuse, dirt, dust, corrosive gases, and fluids
(005) Why is the accuracy at filters, louvers, and coils very rough? - answer✔Due to the
uncertainty of the Ak ( correction factor) area
(005) In order to be measured by the flow hood, how is all of the air forced to flow through the
diffuser or grille? - answer✔A flow hood or capture box completely surrounds and covers a
diffuser or grille
(005) When are flow hoods especially practical? - answer✔In existing buildings where the
manufacturers or Ak factors of the outlets are not known
(005) If you need a tool that functions as a balancing flowmeter you should select - answer✔a
circuit tester
(006) When pipe is needed for a high pressure application you should select - answer✔extra
strong pipe
(006) Pipe should not be threaded when it is - answer✔a wall thickness less than standard weight
(006) When would flanges be installed? - answer✔Wherever it may be necessary to open the
joint for service or replacement of components
(007) What must be done before you apply pressure on the dies? - answer✔Be sure you have the
oil running to help start the segments on the pipe
(007) How are the die segments released? - answer✔Release lever
(008)After you clean the threads of the fitting with a wire brush, what is the next step? -
answer✔Apply a small amount of pipe joint compound to the male threads
