HVAC Star Exam with All Correct & 100% Verified
Answers| Latest Version| Guaranteed To Pass
In a chiller, the refrigerant boils by ___________. ✔Correct Answer-absorbing heat from the water
passing through it
The four main components of a refrigeration system are ✔Correct Answer-compressor, condenser,
evaporator, & metering device
The difference between a contactor and a motor starter is: ✔Correct Answer-overload protection
If refrigerant condenses at a temperature of 105 degrees F and the water leaves the condenser at a
temperature of 95 degrees F, the ___________. ✔Correct Answer-condenser approach
temperature will be 10 degrees
The device that is incorporated into a vacuum steam heating system to protect the vacuum pump
from creating too low (deep) a vacuum is a: ✔Correct Answer-vacuum breaker
The approach temperature for the evaporator is: ✔Correct Answer-the difference in the refrigerant
boiling temperature and the leaving-water temperature
The rotation of a three-phase motor can be reversed by interchanging: ✔Correct Answer-any two
leads
Absolute zero is: ✔Correct Answer--460 degrees F
When a three-phase motor single-phases, it: ✔Correct Answer-draws power from only one phase
If you want to replace a defective capacitor but the only replacements you can find do not have
enough capacitance, you can increase their capacitance by: ✔Correct Answer-connecting two or
more capacitors in parallel
A single-phase motor in which the starting capacitor remains connected when the motor runs is
called a: ✔Correct Answer-permanent-split capacitor motor
When using a thermostatic expansion valve with a __________ charged element, hunting can be
considerably reduced. ✔Correct Answer-cross
A hand placed near a hot stove or fireplace is quickly heated by: ✔Correct Answer-radiation
When an object is refrigerated: ✔Correct Answer-heat is removed from it.
The refrigerant line that connects the condenser to the metering device is ___________ line.
✔Correct Answer-liquid
In a three-phase system, the voltage imbalance between any two legs may not vary by more than:
✔Correct Answer-2%
, A lamp source has a voltage of 110 volts and a current of 0.9 amperes. What is the resistance of the
lamp? ✔Correct Answer-122.2ohms
Lithium-Bromide is used in absorption systems as: ✔Correct Answer-a salt solution
an absorbent (attractant)
a solution that creates a pressure difference
(((all of the above))))
The amount of heat removed to lower the temperature of 15 lbs of water from 48 degrees F to 39
degrees F is: ✔Correct Answer-135 Btu.
Heat flows downhill. This means: ✔Correct Answer-it naturally flows from warmer to colder
substance.
When water is introduced into the end of a chiller it is contained in: ✔Correct Answer-water boxes
Atmospheric pressure at sea level is: ✔Correct Answer-14.7 psi
Refrigerant leaves the compressor through the ___________ line. ✔Correct Answer-discharge line
What is the maximum allowable current imbalance rating in a three-phase supply? ✔Correct
Answer-10%
A dual-element fuse has: ✔Correct Answer-a thermal cutout and a normal fuse link
Electricity results from the movement of tiny negatively charged particles called ✔Correct Answer-
electrons
A hermetic motor should never be energized or tested with a megger when in a deep vacuum
because ✔Correct Answer-the dielectric strength of the motor's insulation would be greatly
reduced.
Lock-out relays are used in air conditioning systems to: ✔Correct Answer-prevent compressor
short-cycling
With a change in temperature, a thermistor will change ✔Correct Answer-resistance
The average house line pressure for Natural Gas is ✔Correct Answer-7" W.C.
A bellows is used: ✔Correct Answer-in both pressure and temperature controllers
In the hot-gas bypass control method, the system component which is bypassed is: ✔Correct
Answer-the condenser.
One type of pressure sensing device uses a flattened metal tube, which is bent into a part circle with
one end fixed in place and connected to a system to be measured. The other end of the tube is
closed and free to move. An increase in pressure tends to straighten the tube. The movement of the
free end of the tube is connected to a dial that reads pressure. This type of gage is called a
✔Correct Answer-bourdon tube
For maximum safety of equipment, overload relays should be: ✔Correct Answer-manual reset type
Answers| Latest Version| Guaranteed To Pass
In a chiller, the refrigerant boils by ___________. ✔Correct Answer-absorbing heat from the water
passing through it
The four main components of a refrigeration system are ✔Correct Answer-compressor, condenser,
evaporator, & metering device
The difference between a contactor and a motor starter is: ✔Correct Answer-overload protection
If refrigerant condenses at a temperature of 105 degrees F and the water leaves the condenser at a
temperature of 95 degrees F, the ___________. ✔Correct Answer-condenser approach
temperature will be 10 degrees
The device that is incorporated into a vacuum steam heating system to protect the vacuum pump
from creating too low (deep) a vacuum is a: ✔Correct Answer-vacuum breaker
The approach temperature for the evaporator is: ✔Correct Answer-the difference in the refrigerant
boiling temperature and the leaving-water temperature
The rotation of a three-phase motor can be reversed by interchanging: ✔Correct Answer-any two
leads
Absolute zero is: ✔Correct Answer--460 degrees F
When a three-phase motor single-phases, it: ✔Correct Answer-draws power from only one phase
If you want to replace a defective capacitor but the only replacements you can find do not have
enough capacitance, you can increase their capacitance by: ✔Correct Answer-connecting two or
more capacitors in parallel
A single-phase motor in which the starting capacitor remains connected when the motor runs is
called a: ✔Correct Answer-permanent-split capacitor motor
When using a thermostatic expansion valve with a __________ charged element, hunting can be
considerably reduced. ✔Correct Answer-cross
A hand placed near a hot stove or fireplace is quickly heated by: ✔Correct Answer-radiation
When an object is refrigerated: ✔Correct Answer-heat is removed from it.
The refrigerant line that connects the condenser to the metering device is ___________ line.
✔Correct Answer-liquid
In a three-phase system, the voltage imbalance between any two legs may not vary by more than:
✔Correct Answer-2%
, A lamp source has a voltage of 110 volts and a current of 0.9 amperes. What is the resistance of the
lamp? ✔Correct Answer-122.2ohms
Lithium-Bromide is used in absorption systems as: ✔Correct Answer-a salt solution
an absorbent (attractant)
a solution that creates a pressure difference
(((all of the above))))
The amount of heat removed to lower the temperature of 15 lbs of water from 48 degrees F to 39
degrees F is: ✔Correct Answer-135 Btu.
Heat flows downhill. This means: ✔Correct Answer-it naturally flows from warmer to colder
substance.
When water is introduced into the end of a chiller it is contained in: ✔Correct Answer-water boxes
Atmospheric pressure at sea level is: ✔Correct Answer-14.7 psi
Refrigerant leaves the compressor through the ___________ line. ✔Correct Answer-discharge line
What is the maximum allowable current imbalance rating in a three-phase supply? ✔Correct
Answer-10%
A dual-element fuse has: ✔Correct Answer-a thermal cutout and a normal fuse link
Electricity results from the movement of tiny negatively charged particles called ✔Correct Answer-
electrons
A hermetic motor should never be energized or tested with a megger when in a deep vacuum
because ✔Correct Answer-the dielectric strength of the motor's insulation would be greatly
reduced.
Lock-out relays are used in air conditioning systems to: ✔Correct Answer-prevent compressor
short-cycling
With a change in temperature, a thermistor will change ✔Correct Answer-resistance
The average house line pressure for Natural Gas is ✔Correct Answer-7" W.C.
A bellows is used: ✔Correct Answer-in both pressure and temperature controllers
In the hot-gas bypass control method, the system component which is bypassed is: ✔Correct
Answer-the condenser.
One type of pressure sensing device uses a flattened metal tube, which is bent into a part circle with
one end fixed in place and connected to a system to be measured. The other end of the tube is
closed and free to move. An increase in pressure tends to straighten the tube. The movement of the
free end of the tube is connected to a dial that reads pressure. This type of gage is called a
✔Correct Answer-bourdon tube
For maximum safety of equipment, overload relays should be: ✔Correct Answer-manual reset type
