UA STAR EXAM 140 EXAM REVIEW 2026/2027 | MOST TESTED
QUESTIONS | HIGH-YIELD PRACTICE QUESTIONS & CORRECT
ANSWERS | COMPLETE STUDY GUIDE | UPDATED VERSION
1. Describe the significance of a steam trap's temperature in diagnosing its
functionality.
A steam trap's temperature does not affect its operation.
A steam trap that is colder than the steam temperature is functioning
correctly.
A steam trap that is warmer than the condensate temperature
indicates it is not functioning properly and may be allowing steam to
escape.
A steam trap that is colder than the condensate temperature is always
defective.
2. Describe how a Variable Frequency Drive impacts the operation of an HVAC
system.
A Variable Frequency Drive only controls the direction of the motor.
A Variable Frequency Drive is used solely for refrigerant management.
A Variable Frequency Drive increases the torque of the motor without
affecting speed.
A Variable Frequency Drive adjusts the speed of the motor to
optimize energy use and system performance.
3. Why is it important to check for pitting and wear due to arcing on contactor
surfaces?
Pitting indicates a need for lubrication, while wear due to arcing is
irrelevant.
Pitting is beneficial for electrical conductivity.
, Pitting and wear due to arcing can affect the contactor's ability to
function properly, leading to system inefficiencies.
Pitting and wear are normal and do not require attention.
4. What is the primary unit of measurement for electrical resistance in HVAC
systems?
Ampere
Ohm
Volt
Watt
5. Which type of air supply outlet is specifically designed to allow air to flow
into a room while minimizing drafts?
Ducts
Grilles
Diffusers
Registers
6. What type of bearing is specifically designed to support vertical loads in a
motor?
Sleeve
Bronze
Thrust
Ball
,7. What is required when using face and bypass dampers on a system with
direct expansion cooling coils?
An end switch on the damper operator should shut down the
compressor when the face damper opens
The bypass damper should remain open all the time during the
cooling operation
The face damper should remain closed during the cooling operation
Compressor capacity control is required
8. In a scenario where a self pumping system is failing to circulate fluid
effectively, which characteristic of passive direct systems might be
contributing to the issue?
Complex electrical components
Dependence on natural forces for fluid movement
Reliance on mechanical pumps
High energy consumption
9. Describe how a failed steam trap can lead to the burnout of a vacuum pump
in a heating system.
A failed steam trap allows steam to escape, reducing system
efficiency.
A failed steam trap leads to backward rotation of the pump.
A failed steam trap causes the pump to operate at incorrect voltage.
A failed steam trap can cause excessive pressure buildup, leading to
overheating and burnout of the vacuum pump.
, 10. Describe the importance of recovering and reclaiming refrigerant in HVAC
systems.
Recovering refrigerant is unnecessary if the system is functioning
properly.
Reclaiming refrigerant is only needed during system installation.
Recovering and reclaiming refrigerant prevents environmental
harm and ensures compliance with regulations.
Recycling refrigerant is the only requirement for HVAC systems.
11. When a ladder is properly erected, what is the required distance between
the base of the ladder and the side of the building?
1/4 the ladder length
1/8 the ladder length
1/2 the ladder length
1/3 the ladder length
12. Describe the significance of the atmospheric pressure value of 14.7 psi at sea
level in relation to HVAC systems.
14.7 psi is the maximum pressure allowed in HVAC systems.
Atmospheric pressure affects only the temperature of refrigerants.
The atmospheric pressure of 14.7 psi at sea level is crucial for
calculating refrigerant pressures and ensuring proper system
operation.
The atmospheric pressure is irrelevant to HVAC systems.
QUESTIONS | HIGH-YIELD PRACTICE QUESTIONS & CORRECT
ANSWERS | COMPLETE STUDY GUIDE | UPDATED VERSION
1. Describe the significance of a steam trap's temperature in diagnosing its
functionality.
A steam trap's temperature does not affect its operation.
A steam trap that is colder than the steam temperature is functioning
correctly.
A steam trap that is warmer than the condensate temperature
indicates it is not functioning properly and may be allowing steam to
escape.
A steam trap that is colder than the condensate temperature is always
defective.
2. Describe how a Variable Frequency Drive impacts the operation of an HVAC
system.
A Variable Frequency Drive only controls the direction of the motor.
A Variable Frequency Drive is used solely for refrigerant management.
A Variable Frequency Drive increases the torque of the motor without
affecting speed.
A Variable Frequency Drive adjusts the speed of the motor to
optimize energy use and system performance.
3. Why is it important to check for pitting and wear due to arcing on contactor
surfaces?
Pitting indicates a need for lubrication, while wear due to arcing is
irrelevant.
Pitting is beneficial for electrical conductivity.
, Pitting and wear due to arcing can affect the contactor's ability to
function properly, leading to system inefficiencies.
Pitting and wear are normal and do not require attention.
4. What is the primary unit of measurement for electrical resistance in HVAC
systems?
Ampere
Ohm
Volt
Watt
5. Which type of air supply outlet is specifically designed to allow air to flow
into a room while minimizing drafts?
Ducts
Grilles
Diffusers
Registers
6. What type of bearing is specifically designed to support vertical loads in a
motor?
Sleeve
Bronze
Thrust
Ball
,7. What is required when using face and bypass dampers on a system with
direct expansion cooling coils?
An end switch on the damper operator should shut down the
compressor when the face damper opens
The bypass damper should remain open all the time during the
cooling operation
The face damper should remain closed during the cooling operation
Compressor capacity control is required
8. In a scenario where a self pumping system is failing to circulate fluid
effectively, which characteristic of passive direct systems might be
contributing to the issue?
Complex electrical components
Dependence on natural forces for fluid movement
Reliance on mechanical pumps
High energy consumption
9. Describe how a failed steam trap can lead to the burnout of a vacuum pump
in a heating system.
A failed steam trap allows steam to escape, reducing system
efficiency.
A failed steam trap leads to backward rotation of the pump.
A failed steam trap causes the pump to operate at incorrect voltage.
A failed steam trap can cause excessive pressure buildup, leading to
overheating and burnout of the vacuum pump.
, 10. Describe the importance of recovering and reclaiming refrigerant in HVAC
systems.
Recovering refrigerant is unnecessary if the system is functioning
properly.
Reclaiming refrigerant is only needed during system installation.
Recovering and reclaiming refrigerant prevents environmental
harm and ensures compliance with regulations.
Recycling refrigerant is the only requirement for HVAC systems.
11. When a ladder is properly erected, what is the required distance between
the base of the ladder and the side of the building?
1/4 the ladder length
1/8 the ladder length
1/2 the ladder length
1/3 the ladder length
12. Describe the significance of the atmospheric pressure value of 14.7 psi at sea
level in relation to HVAC systems.
14.7 psi is the maximum pressure allowed in HVAC systems.
Atmospheric pressure affects only the temperature of refrigerants.
The atmospheric pressure of 14.7 psi at sea level is crucial for
calculating refrigerant pressures and ensuring proper system
operation.
The atmospheric pressure is irrelevant to HVAC systems.
