Air Conditioning Repair Service 4

Question 1

A technician measures a compressor's amp draw and finds it is above the rated full-load amps (FLA). Which condition would most likely cause this?

Accepted Answer

High condensing temperature due to poor heat rejection

Answer

High condensing temperatures increase the pressure ratio the compressor must work against, forcing it to draw more current than its rated FLA.

Question 2

When evacuating a refrigeration system, the vacuum pump should be connected to:

Accepted Answer

Both the high and low side service ports simultaneously

Answer

Connecting to both service ports ensures a faster, more complete evacuation by removing moisture and non-condensables from both sides of the system.

Question 3

What micron level must be achieved and held during system evacuation before charging with refrigerant?

Accepted Answer

500 microns or lower

Answer

Industry standards require pulling the system down to 500 microns or lower and verifying the level holds to confirm adequate moisture removal and leak integrity.

Question 4

A homeowner reports that the AC runs constantly but never reaches the set temperature. After inspection, the technician finds the evaporator coil is clean and airflow is good. The NEXT diagnostic step should be:

Accepted Answer

Measure system operating pressures and temperatures

Answer

Measuring operating pressures and temperatures provides the data needed to diagnose whether the issue is refrigerant charge, metering device, or compressor performance.

Question 5

Which tool is used to verify that a crankcase heater on a compressor is functioning properly?

Accepted Answer

Clamp-style ammeter or infrared thermometer

Answer

A clamp-style ammeter measures the small current draw of the crankcase heater, while an infrared thermometer confirms the heater is producing heat at the compressor base.

Air Conditioning Repair Practice Test

Air Conditioning Repair Practice Test

Air Conditioning Repair Service 4