CFC System Charging & Evacuation 4

Question 1

What is the purpose of performing a standing vacuum test after evacuation?

Accepted Answer

To confirm the system holds vacuum with no leaks or moisture present

Answer

A standing vacuum test isolates the system from the pump and monitors the micron reading over time to verify the absence of leaks and significant moisture.

Question 2

When must a technician use recovery equipment before opening a CFC or HCFC system for repair?

Accepted Answer

Always, regardless of charge size, when the system contains a regulated refrigerant

Answer

EPA Section 608 requires refrigerant recovery before opening any system containing a regulated refrigerant, regardless of the charge size.

Question 3

A technician charges a split system by subcooling method. What measurement is needed to calculate the correct charge?

Accepted Answer

Liquid line temperature and liquid line saturation pressure/temperature

Answer

The subcooling method requires measuring the liquid line temperature and comparing it to the saturation temperature at the liquid line pressure to calculate actual subcooling.

Question 4

What color are DOT-approved recovery cylinders painted to distinguish them from refrigerant supply cylinders?

Accepted Answer

Gray with a yellow collar

Answer

Recovery cylinders are standardized with a gray body and yellow collar (top) to distinguish them from manufacturer supply cylinders.

Question 5

Which of the following would cause a system to be overcharged after a charging-by-superheat procedure?

Accepted Answer

The indoor unit filter was heavily clogged during charging

Answer

A clogged filter reduces airflow across the evaporator, artificially raising superheat readings and causing the technician to add excess refrigerant.

(CFC) Chlorofluorocarbon Certification Practice Test

(CFC) Chlorofluorocarbon Certification Practice Test

CFC System Charging & Evacuation 4