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50 terms

NATE Final Exam #1

STUDY
PLAY
Generally, vibration eliminators in piping should be installed:

A: At a 45 degree angle

B: At a 90 degree angle

C: Perpendicular to the compressor crankshaft

D: Parallel to the compressor crankshaft
D: Parallel to the compressor crankshaft
If you purchased ten filter-driers for $100.00, what was the price of each filter-drier?

A: $100.00

B: $10.00

C: $1.00

D: $1.10
B: $10.00
Which of the following jobs requires safety glasses?

A: Driving a vehicle

B: Extending a ladder

C: Brazing

D: Pulling thermostat wire
C: Brazing
Which of the following instruments would typically be used to measure a vacuum?

A: Micron gauge

B: Thermostat

C: Anemometer

D: Differential pressure gauge
A: Micron gauge
ASHRAE Standard 34 deals with:

A: Carbon monoxide safety levels

B: Refrigerant quality

C: Equipment room ventilation and alarms

D: Refrigerant toxicity and flammability
D: Refrigerant toxicity and flammability

ANSI/ASHRAE 34 published in 2001 and entitled "Designation and Safety Classification of Refrigerants".
• Class A signifies refrigerants for which toxicity has not been identified at concentrations less than or equal to 400 ppm;
• Class B signifies refrigerants for which there is evidence of toxicity at concentrations below 400 ppm.
• Class 1 indicates refrigerants that do not show flame propagation when tested in air at 21°C and 101 kPa;
• Class 2 indicates refrigerants having a lower flammability limit of more than 0.10 kg/m3 at 21°C and 101 kPa and a heat of combustion of less than 19 kJ/kg;
• Class 3 indicates refrigerants that are highly flammable as defined by a lower flammability limit of less than or equal to 0.10 kg/m3 at 21°C and 101 kPa or a heat of combustion greater than or equal to 19 kJ/kg.
What control would you use on a capillary tube or automatic expansion valve system to maintain the desired temperature?

A: Dual pressure control

B: High pressure control

C: Thermostatic temperature control

D: Low pressure control
C: Thermostatic temperature control
The total heat contained in any substance is obtained by adding together its:

A: Radiant and specific heat

B: Latent and sensible heat

C: Radiant and sensible heat

D: Specific and latent heat
B: Latent and sensible heat
An outdoor air conditioning condensing unit should not be located:

A: In the sun

B: On the side of the house

C: Within 5 feet of a hose bib connection

D: Where any objects or obstructions are within 5 feet of the condenser fan
D: Where any objects or obstructions are within 5 feet of the condenser fan
An outdoor air conditioning condensing unit should not be located:

A: Under an overhang where water may drain onto it

B: Within 4 feet of a hose bib connection

C: Within 3 feet of an electrical disconnect

D: All of the above
A: Under an overhang where water may drain onto it
A thermostat should be mounted:

A: Approximately 5 feet above the floor

B: Level

C: On an inside wall

D: All of the above
D: All of the above
As the pressure on a liquid rises, the temperature at which the liquid will boil:
A: Varies

B: Remains the same

C: Increases

D: Decreases
C: Increases
A voltmeter is connected to a circuit:

A: In series

B: In parallel

C: Crossover

D: Delta
B: In parallel
Pressure relief valves are not to be piped:

A: In parallel

B: In series

C: Facing up

D: Within 12" of a wall
B: In series
Which of the following is typically covered by local codes?

A: Refrigerant type

B: Maximum length of refrigerant lines

C: Location of condensing unit disconnect

D: Location of liquid and suction line service valves
C: Location of condensing unit disconnect
Hard drawn ACR tubing may not be used:

A: In combination with soft drawn ACR tubing

B: Without first annealing the tubing

C: With a swedge joint

D: On residential applications
C: With a swedge joint
Which of the following oils is the most hygroscopic?

A: POE oil

B: Mineral oil

C: Vegetable oil

D: Vacuum pump oil
A: POE oil
Highly hygroscopic oils must be kept in:

A: Metal or glass containers

B: Tightly capped plastic containers

C: An area out of direct sunlight

D: A refrigerated space 50 degrees or cooler
A: Metal or glass containers
The purpose of technician certification is to:

A: Raise the competency level of technicians

B: Decrease the number of poorly installed and improperly serviced systems

C: Help consumers choose well-trained technicians

D: All of the above
D: All of the above
The purpose of converting psig to psia prior to calculating the compression ratio of a system is to:

A: Make the answer come out as a positive number if the low side pressure is in a vacuum

B: Make sure the answer is never negative

C: Make the answer mathematically correct

D: Allow for easy conversion to the metric system
C: Make the answer mathematically correct
As a warm air furnace raises the temperature of the air in a structure, the relative humidity of the space will:

A: Increase

B: Decrease

C: Increase by the square of the change in temperature

D: Remain the same
B: Decrease
ACR soft copper tubing comes in:

A: 20 foot lengths

B: 30 foot sealed rolls

C: 50 foot rolls

D: 50 foot sealed rolls
D: 50 foot sealed rolls
Typical ACR copper tubing flares are:

A: Double flares

B: 33 degree flares

C: 45 degree flares

D: 60 degree flares
C: 45 degree flares
Customers generally trust technicians who:

A: Look them straight in the eye during conversations

B: Genuinely listen to the customer's concerns

C: Provide them with accurate information and options

D: All of the above are correct
D: All of the above are correct
What amount of oxygen is normally contained in air?

A: 10%

B: 15%

C: 21%

D: 25%
C: 21%
The "critical temperature" and pressure of a refrigerant is:
A: The conditions above which a refrigerant gas cannot be condensed into a liquid
B: The conditions below which a refrigerant cannot be vaporized to a gas
C: The conditions where even if a change of state were to occur, no latent heat exists
D: The pressure at which no heat exists in the refrigerant therefore the temperature is absolute zero
A: The conditions above which a refrigerant gas cannot be condensed into a liquid
Refrigerant cylinders should never be filled to over:

A: 50%

B: 65%

C: 80%

D: 90%
C: 80%
Which of the following gases should never be used to pressure test for leaks?

A: Nitrogen

B: Oxygen

C: Carbon dioxide

D: None of these should be used for pressure testing
B: Oxygen
What is the nominal operating wattage of a one-quarter horsepower electric motor?

A: 186 watts

B: 100 watts

C: 46 watts

D: 373 watts
A: 186 watts
The electrical resistance of a thermistor _________ with a temperature increase.

A: increases

B: decreases

C: remains unchanged

D: varies by the 10th power
B: decreases
Removing refrigerant from a system and storing it in a cylinder without performing any testing or processing is called:

A: Recycling

B: Reclaiming

C: Recovering

D: Restoring
C: Recovering
Processing used refrigerant to bring it up to the standards of new virgin refrigerant is called:

A: Recycling

B: Reclaiming

C: Recovering

D: Restoring
B: Reclaiming
The quality standard for new virgin refrigerant is:

A: ARI 700

B: ARI 740

C: ARI 2030

D: UL 15
A: ARI 700
Which of the following is not a suitable control for an air side economizer as used on a packaged unit air conditioning system?

A: Enthalpy control

B: Outside air thermostat

C: Neither a nor b

D: Low pressure control
D: Low pressure control
What two pressures can a pitot tube measure?

A: Static and total

B: Velocity and total

C: Velocity and static

D: Total and external static pressure
A: Static and total
An oil separator has which of the following lines or connections attached to it?

A: Inlet, outlet, oil line

B: Inlet and outlet

C: Inlet and oil line

D: None of these is correct
A: Inlet, outlet, oil line
A three-position service valve located on the outlet of a receiver should be left in what position for normal operation with no gauges attached?

A: Front-seated

B: Mid-seated

C: Back-seated

D: Cracked
C: Back-seated
A cooling tower is treated for what two conditions?

A: Algae and scale

B: Algae and lime

C: Scale and disease

D: Algae and disease
A: Algae and scale
Which of the following documents are required by law?

A: Air balance report

B: Charging chart

C: Equipment list

D: MSDS sheets
D: MSDS sheets
A heating and/or cooling load calculation is used to:

A: Choose the correct equipment size

B: Determine the correct duct sizes

C: Determine the correct cfm to each room

D: All of the above
D: All of the above
What component of a dehumidifier can be used to reheat the air after dehumidification has taken place?

A: Evaporator

B: Condenser

C: Compressor

D: None of the above
B: Condenser
Type 1 EPA refrigerant certification is for systems:

A: Containing 5 pounds or less of refrigerant

B: Containing 8 pounds or less of refrigerant

C: Containing 5 pounds or less of refrigerant and having fixed service valves

D: Containing 5 pounds or less of refrigerant and having no service valves
D: Containing 5 pounds or less of refrigerant and having no service valves
The operating pressures in an R-410A system are:

A: 40% to 70% higher than in an R-22 system

B: 10% to 15% higher than in an R-22 system

C: Lower than in an R-22 system

D: Approximately the same as in an R-22 system
A: 40% to 70% higher than in an R-22 system
R-410A systems use which of the following refrigerant oils?

A: Mineral

B: Alkylbenzene

C: Polyol ester

D: Glycols
C: Polyol ester
Carbon monoxide poisoning is often mistaken for:

A: The flu

B: Diabetes

C: Blood disease

D: Chronic low blood pressure
A: The flu
Carbon monoxide is the result of:

A: Incomplete combustion

B: Lowering the temperature of the flame

C: Excessive fuel or a lack of oxygen

D: All of the above
D: All of the above
The complete combustion of natural gas requires:

A: 5 cubic feet of air per cubic foot of gas

B: 10 cubic feet of air per cubic foot of gas

C: 15 cubic feet of air per cubic foot of gas

D: 20 cubic feet of air per pound of natural gas
C: 15 cubic feet of air per cubic foot of gas
A tightly constructed building generally causes the pressure inside the building to be ______ than the pressure outside.

A: Higher

B: Lower

C: The same

D: None of these
B: Lower
R-410A is a ____ refrigerant.

A: CFC

B: HCFC

C: HFC

D: POE
C: HFC
A refrigerant classified as an "Azeotropic blend":

A: Will not fractionate

B: Behaves much like a single-component pure refrigerant

C: Does not have a temperature glide

D: All of the above are correct
D: All of the above are correct
Superheat is:

A: Difference between saturation temperature in evaporator and temperature of refrigerant leaving evaporator

B: Difference between saturation temperature in evaporator and saturation temperature in condenser

C: Difference between temperature measured at the compressor suction and compressor discharge lines

D: A single temperature taken in the center of the evaporator minus the ambient air temperature
A: Difference between saturation temperature in evaporator and temperature of refrigerant leaving evaporator