EPA Section 608 Universal Certification ExamType II (High-Pressure Appliances)Easy
A technician is using a self-contained (active) recovery unit to recover R-407C from a high-pressure appliance. What is the primary method by which this type of recovery unit removes refrigerant from the system?
- ABy absorbing the refrigerant into a desiccant material.
- BBy relying solely on the appliance's internal pressure to push refrigerant out.
- CBy using a compressor to actively pump refrigerant out of the system.
- DBy cooling the recovery cylinder to create a pressure differential.
Show answer & explanationAnswer & explanation
Correct answer: C. By using a compressor to actively pump refrigerant out of the system.
Self-contained (active) recovery units contain their own compressor, which actively draws refrigerant vapor and/or liquid from the appliance and compresses it into the recovery cylinder. This method does not rely on the pressure differential created by temperature differences, unlike passive recovery.
Why the other options are wrong
- A. Desiccants remove moisture, not refrigerant.
- B. This describes a system-dependent (passive) recovery method, not a self-contained (active) unit.
- D. Cooling the recovery cylinder primarily aids passive recovery or speeds up active recovery, but isn't the primary mechanism of an active unit.
Self-Contained Recovery Unit Mechanism
Self-contained (active) recovery units use their own compressor to remove refrigerant from an appliance.
- They actively pump refrigerant, overcoming system pressure.
- Faster and more efficient than passive recovery.
- Can recover both liquid and vapor refrigerant.
Memory trick: Active units pump, passive units wait for the pressure jump!