Air Conditioning Repair Air Conditioning Repair Preventive Maintenance and System Efficiency 2

Question 1

What is the correct procedure for testing a dual-run capacitor on a residential AC unit?

Accepted Answer

Discharge it, then test capacitance with a capacitor-rated multimeter

Answer

A dual-run capacitor must be safely discharged before testing its capacitance with a meter rated for capacitor testing.

Question 2

Which measurement indicates proper lubrication is needed on older belt-drive blower motors?

Accepted Answer

Motor running hot above its rated temperature or unusual squealing noise

Answer

Excessive heat or squealing from a belt-drive motor bearing signals inadequate lubrication and potential bearing failure.

Question 3

A technician measures the outdoor ambient temperature at 95°F. What is the expected normal operating range for high-side (discharge) pressure on an R-410A system?

Accepted Answer

380–420 PSIG

Answer

For R-410A at 95°F ambient, normal high-side (condensing) pressure is typically in the 380–420 PSIG range.

Question 4

What is the purpose of a condensate trap installed on an AC air handler?

Accepted Answer

To prevent negative duct pressure from pulling sewer gases back through the drain line

Answer

A condensate trap creates a water seal that prevents negative static pressure in the air handler from breaking the drain flow and introducing odors or pathogens.

Question 5

During a maintenance check, the technician notices the outdoor fan motor is drawing more amps than its nameplate rating. What is the most likely cause?

Accepted Answer

Failing motor bearings or a failing capacitor

Answer

A motor drawing above nameplate amperage usually indicates worn bearings creating drag or a weak start/run capacitor failing to support the motor.

Air Conditioning Repair Practice Test

Air Conditioning Repair Practice Test

Air Conditioning Repair Air Conditioning Repair Preventive Maintenance and System Efficiency 2