FREE Air Conditioning Repair Condenser Unit Repair Questions and Answers

Question 1

A technician is diagnosing a residential condenser unit that is running, but the homeowner reports poor cooling performance.
Upon inspection, the technician observes that the condenser fan motor is running, but the fan blades are turning very slowly and intermittently.
What is the most likely cause of this issue?

Accepted Answer

A faulty run capacitor for the condenser fan motor.

Answer

A low refrigerant charge in the system.

Answer

A clogged air filter in the indoor unit.

Answer

A short circuit in the compressor windings.

Question 2

During a routine maintenance check, a technician notices that the condenser coil of an outdoor unit is heavily restricted with dirt, leaves, and debris. Which of the following is the most direct consequence of this condition on the unit's operation and efficiency?

Accepted Answer

Increased head pressure and reduced heat rejection.

Answer

Decreased suction pressure and potential liquid floodback.

Answer

Premature failure of the evaporator fan motor.

Answer

Reduced refrigerant flow through the expansion device.

Question 3

A homeowner reports that their outdoor condenser unit makes a loud 'rattling' or 'vibrating' noise when it starts up and during operation. The cooling performance seems adequate. Upon inspection, the technician finds that all major components (compressor, fan motor) appear to be securely mounted. What is a common, often overlooked, cause for such noise in a condenser unit?

Accepted Answer

Loose fan motor mounting bolts or fan blade out of balance.

Answer

A failing compressor internal component.

Answer

A restricted liquid line filter drier.

Answer

An overcharged refrigerant system.

Question 4

When replacing a condenser fan motor, what critical electrical specification must be matched to the original motor to ensure proper and safe operation?

Accepted Answer

Voltage and Amperage.

Answer

Horsepower (HP) and Revolutions Per Minute (RPM).

Answer

Frame size and shaft diameter.

Answer

Capacitor Microfarad (µF) rating.

Question 5

A technician is troubleshooting a condenser unit where the compressor is running continuously, but the condenser fan motor is not operating. The condenser fan motor's capacitor tests good, and 240V AC is confirmed at the motor terminals. What is the most probable cause of the fan motor not running?

Accepted Answer

The condenser fan motor itself has failed internally.

Answer

The contactor's auxiliary contacts for the fan motor are stuck open.

Answer

The low-pressure switch has opened.

Answer

The indoor thermostat is set to 'Fan On' instead of 'Auto'.

Question 6

Which of the following is a direct result of a severely undersized condenser unit for a given heat load?

Accepted Answer

The unit will run excessively, struggle to reach desired temperatures, and likely have high utility bills.

Answer

The compressor will short-cycle frequently, leading to rapid wear and tear.

Answer

The evaporator coil will consistently freeze up due to insufficient airflow.

Answer

The refrigerant charge will become critically low, requiring frequent top-offs.