Question 1

Which of the following would be considered noncondensable gas/es in a refrigeration system?

Accepted Answer

A)  nitrogen 
B)  refrigerant 
C)  vaporized refrigerant oil 
D)  air 
E)  both a and d 
A)  nitrogen 
B)  refrigerant 
C)  vaporized refrigerant oil 
D)  air 
E)  both a and d

Question 2

List four possible fan motor mechanical problems.

Accepted Answer

improper airflow, im

Question 3

Which of the following is a condition of an air conditioning system that is undercharged?

Accepted Answer

A)  increased possibility of floodback to the compressor 
B)  higher operating pressures 
C)  low operating pressures 
D)  reduced evaporator superheat 
A)  increased possibility of floodback to the compressor 
B)  higher operating pressures 
C)  low operating pressures 
D)  reduced evaporator superheat

Question 4

Which of the following is NOT a condition of a belt on a blower motor being too loose?

Accepted Answer

A)  reduced air flow 
B)  belt slippage 
C)  excessive noise 
D)  motor overheating 
A)  reduced air flow 
B)  belt slippage 
C)  excessive noise 
D)  motor overheating

Question 5

If, while troubleshooting an R-22 residential air conditioning system at near design conditions, the operating pressures are found to be 40 psig on the low side and 116 psig on the high side, it is most likely that the system is

Accepted Answer

A)  overcharged 
B)  operating with a dirty condenser 
C)  undercharged 
D)  operating properly 
A)  overcharged 
B)  operating with a dirty condenser 
C)  undercharged 
D)  operating properly

Question 6

If, while troubleshooting an R-410A residential air conditioning system at near design conditions, the operating pressures are found to be 118 psig on the low side and 440 psig on the high side, it is most likely that the system is

Accepted Answer

A)  operating with a dirty air filter 
B)  operating with a refrigerant overcharge 
C)  operating with an undercharge of refrigerant 
D)  operating properly 
A)  operating with a dirty air filter 
B)  operating with a refrigerant overcharge 
C)  operating with an undercharge of refrigerant 
D)  operating properly

Which of the following would be considered noncondensable gas/es in a refrigeration system?

List four possible fan motor mechanical problems.

Which of the following is a condition of an air conditioning system that is undercharged?

Which of the following is NOT a condition of a belt on a blower motor being too loose?

If, while troubleshooting an R-22 residential air conditioning system at near design conditions, the operating pressures are found to be 40 psig on the low side and 116 psig on the high side, it is most likely that the system is

If, while troubleshooting an R-410A residential air conditioning system at near design conditions, the operating pressures are found to be 118 psig on the low side and 440 psig on the high side, it is most likely that the system is

Matter, Energy, and Heat Basics

The Refrigeration Process

General Safety Practices

Refrigerant Management

Hand Tools

Tubing and Piping Tools

Specialized Hvacr Tools

System Location

Air-Distribution Systems

System Connections

Leak Testing

System Evacuation

System Startup and Charging

Electricity Fundamentals

Electric Motors and Starting Components

Electronic Controls

Wiring Diagrams

Electric Codes

Testing, Adjusting and Balancing

Indoor Air Quality

Electrical Troubleshooting

Electric Heat

Gas Heat

Oil Heat

Hydronic Heat

Heat Pumps

Filters

Exam 21: Mechanical Troubleshooting

Which of the following would be considered noncondensable gas/es in a refrigeration system?

List four possible fan motor mechanical problems.

Which of the following is a condition of an air conditioning system that is undercharged?

Which of the following is NOT a condition of a belt on a blower motor being too loose?

If, while troubleshooting an R-22 residential air conditioning system at near design conditions, the operating pressures are found to be 40 psig on the low side and 116 psig on the high side, it is most likely that the system is

If, while troubleshooting an R-410A residential air conditioning system at near design conditions, the operating pressures are found to be 118 psig on the low side and 440 psig on the high side, it is most likely that the system is

Matter, Energy, and Heat Basics

The Refrigeration Process

General Safety Practices

Refrigerant Management

Hand Tools

Tubing and Piping Tools

Specialized Hvacr Tools

System Location

Air-Distribution Systems

System Connections

Leak Testing

System Evacuation

System Startup and Charging

Electricity Fundamentals

Electric Motors and Starting Components

Electronic Controls

Wiring Diagrams

Electric Codes

Testing, Adjusting and Balancing

Indoor Air Quality

Electrical Troubleshooting

Electric Heat

Gas Heat

Oil Heat

Hydronic Heat

Heat Pumps

Filters