HVAC Competency Exam with All Correct & 100%
Verified Answers |Latest Version| Already Graded
A+
If a natural gas piping system fails a pressure test, the technician must re-pressurize the system and
check for leaks with? ✔Correct Answer-soap bubbles
a pressure relief valve is installed to? ✔Correct Answer-avoid exceeding the system limits
In a refrigeration system, what must be installed at 10' intervals on the suction line if the compressor
is above the evaporator? ✔Correct Answer-Trap
What occurs if a 3 amp load is connected to the secondary winding of a 24 volt, 40 V.A. transformer?
✔Correct Answer-Transformer will fail due to an overload
Flue vent pipe size is determined by the? ✔Correct Answer-Appliance manufacturer and IFGC
In a split system, the condensing unit is remotely located away from the? ✔Correct Answer-
Thermistor
Which electronic control is designed to increase or decrease it's resistance with a change in
temperature? ✔Correct Answer-thermistor
Documents that provide information about the hazardous products are ccalled? ✔Correct Answer-
Safety Data Sheet
A type B gas vent is? ✔Correct Answer-Double-walled
How many BTu's are required to melt one ton of ice in a 24 hour period? ✔Correct Answer-288,000
What is replaced when changing a fusible link on an electric heater? ✔Correct Answer-High limit
switch
When retro-fitting an R-22 system to a R-407C refrigerant system, it is necessary to change the?
✔Correct Answer-Lubricant from mineral oil to POE oil
Which condition exists if the heat loss of a structure equals the capacity output of the system?
✔Correct Answer-The balance point has been reached
A combination wiring and crimping tool is used to? ✔Correct Answer-Cut and strip wire
What is the saturation temperature of R-22 at 69 psig? ✔Correct Answer-40 F
If the temperature rise (delta T) of the heat exhanger on a gas furnace exceeds the manufacturers
specifications, the technician should do _____? ✔Correct Answer-increase the motor speed for
higher CFM
, The nominal CFM required per ton of air conditioning is? ✔Correct Answer-400
Which refrigerant has a zero ozone depletion potential but is still considered a greenhouse gas?
✔Correct Answer-R134a
If a TXV power element loses its charge it results in a? ✔Correct Answer-Starved evaporator
Before using an empty recovery cylinder it should be evacuated to how many microns? ✔Correct
Answer-500 microns
The motor shaft rotation direction is located on the? ✔Correct Answer-Motor nameplate attached
to the motor body
Using a voltmeter a technician can identify an open contact on a SPST switch in a A/C series circuit by
reading? ✔Correct Answer-Voltage across contacts
The difference between the "cut-in" and "cut-out" settings of a high pressure control switch is called
the? ✔Correct Answer-Differential
Which load is controlled by the W2 thermostat contact? ✔Correct Answer-second stage heating
Carbon monoxide and radon are classified as? ✔Correct Answer-Air contaminants
On a refrigeration system, what is the type of motor that has a 2-wire, 9 watt condenser fan motor?
✔Correct Answer-Shaded pole
What is on eof the first things to check for if there is an ignition problem when installing a high
efficiency ICF controlled furance? ✔Correct Answer-improper polarity
To determine the correct amount of ventilation air for a specific application the technician must
consult? ✔Correct Answer-International mechanical code book
Which component of an air conditioner is energized continuously? ✔Correct Answer-crankcase
heater
Which calculation determines superheat? ✔Correct Answer-subtract the converted suction
pressure temperature from the suction line temperature
What scale is used to test the evenness of fan blades? ✔Correct Answer-Balance
The purpose of an EPR valve is to? ✔Correct Answer-maintain the correct evaporator pressure
Which refrigerant line must be insulated to prevent moisture condensation? ✔Correct Answer-
suction line
Which refrigerant is chlorine free? ✔Correct Answer-R410a
the total resistance of the windings in a single phase compressor must equal the? ✔Correct
Answer-resistance of the the run winding plus the start winding
Verified Answers |Latest Version| Already Graded
A+
If a natural gas piping system fails a pressure test, the technician must re-pressurize the system and
check for leaks with? ✔Correct Answer-soap bubbles
a pressure relief valve is installed to? ✔Correct Answer-avoid exceeding the system limits
In a refrigeration system, what must be installed at 10' intervals on the suction line if the compressor
is above the evaporator? ✔Correct Answer-Trap
What occurs if a 3 amp load is connected to the secondary winding of a 24 volt, 40 V.A. transformer?
✔Correct Answer-Transformer will fail due to an overload
Flue vent pipe size is determined by the? ✔Correct Answer-Appliance manufacturer and IFGC
In a split system, the condensing unit is remotely located away from the? ✔Correct Answer-
Thermistor
Which electronic control is designed to increase or decrease it's resistance with a change in
temperature? ✔Correct Answer-thermistor
Documents that provide information about the hazardous products are ccalled? ✔Correct Answer-
Safety Data Sheet
A type B gas vent is? ✔Correct Answer-Double-walled
How many BTu's are required to melt one ton of ice in a 24 hour period? ✔Correct Answer-288,000
What is replaced when changing a fusible link on an electric heater? ✔Correct Answer-High limit
switch
When retro-fitting an R-22 system to a R-407C refrigerant system, it is necessary to change the?
✔Correct Answer-Lubricant from mineral oil to POE oil
Which condition exists if the heat loss of a structure equals the capacity output of the system?
✔Correct Answer-The balance point has been reached
A combination wiring and crimping tool is used to? ✔Correct Answer-Cut and strip wire
What is the saturation temperature of R-22 at 69 psig? ✔Correct Answer-40 F
If the temperature rise (delta T) of the heat exhanger on a gas furnace exceeds the manufacturers
specifications, the technician should do _____? ✔Correct Answer-increase the motor speed for
higher CFM
, The nominal CFM required per ton of air conditioning is? ✔Correct Answer-400
Which refrigerant has a zero ozone depletion potential but is still considered a greenhouse gas?
✔Correct Answer-R134a
If a TXV power element loses its charge it results in a? ✔Correct Answer-Starved evaporator
Before using an empty recovery cylinder it should be evacuated to how many microns? ✔Correct
Answer-500 microns
The motor shaft rotation direction is located on the? ✔Correct Answer-Motor nameplate attached
to the motor body
Using a voltmeter a technician can identify an open contact on a SPST switch in a A/C series circuit by
reading? ✔Correct Answer-Voltage across contacts
The difference between the "cut-in" and "cut-out" settings of a high pressure control switch is called
the? ✔Correct Answer-Differential
Which load is controlled by the W2 thermostat contact? ✔Correct Answer-second stage heating
Carbon monoxide and radon are classified as? ✔Correct Answer-Air contaminants
On a refrigeration system, what is the type of motor that has a 2-wire, 9 watt condenser fan motor?
✔Correct Answer-Shaded pole
What is on eof the first things to check for if there is an ignition problem when installing a high
efficiency ICF controlled furance? ✔Correct Answer-improper polarity
To determine the correct amount of ventilation air for a specific application the technician must
consult? ✔Correct Answer-International mechanical code book
Which component of an air conditioner is energized continuously? ✔Correct Answer-crankcase
heater
Which calculation determines superheat? ✔Correct Answer-subtract the converted suction
pressure temperature from the suction line temperature
What scale is used to test the evenness of fan blades? ✔Correct Answer-Balance
The purpose of an EPR valve is to? ✔Correct Answer-maintain the correct evaporator pressure
Which refrigerant line must be insulated to prevent moisture condensation? ✔Correct Answer-
suction line
Which refrigerant is chlorine free? ✔Correct Answer-R410a
the total resistance of the windings in a single phase compressor must equal the? ✔Correct
Answer-resistance of the the run winding plus the start winding
