CFC HVAC Systems & Leak Detection 5

Question 1

What is 'formicary corrosion' and why is it significant for HVAC leak detection?

Accepted Answer

A form of copper corrosion caused by formic or acetic acid producing pinhole leaks

Answer

Formicary corrosion is caused by organic acids (formic, acetic) reacting with copper in the presence of moisture, creating characteristic tunnel-like pinholes that leak refrigerant.

Question 2

When recovering refrigerant from a system suspected of having a large leak, what precaution is most important before beginning recovery?

Accepted Answer

Identify the refrigerant type to use the correct recovery equipment and cylinders

Answer

Identifying the refrigerant type is critical to avoid cross-contamination, use correct recovery equipment rated for that refrigerant, and comply with handling regulations.

Question 3

A technician measures compressor discharge temperature significantly above normal while suction pressure is below normal. What refrigerant system fault does this suggest?

Accepted Answer

Low refrigerant charge causing high compression ratio and superheat

Answer

A low charge increases the compression ratio and allows excessive superheat to reach the compressor, raising discharge temperature well above normal.

Question 4

Which EPA record-keeping requirement applies when more than 50 pounds of refrigerant is added to a system during the calendar year?

Accepted Answer

The owner must maintain records of the refrigerant added and leak inspections performed

Answer

EPA Section 608 requires owners of appliances with 50+ lbs of refrigerant to keep records of refrigerant added and to document leak inspection dates and results.

Question 5

In a heat pump system operating in heating mode, which pressure side should a technician probe first when searching for leaks using an electronic detector?

Accepted Answer

High-pressure discharge side, since higher pressure drives refrigerant through leak paths faster

Answer

Higher system pressure on the discharge side forces refrigerant through any existing leak path more rapidly, making leaks more detectable on the high side.

(CFC) Chlorofluorocarbon Certification Practice Test

(CFC) Chlorofluorocarbon Certification Practice Test

CFC HVAC Systems & Leak Detection 5