EPA 608 Type II Practice Test 2

Question 1

What is the recovery requirement for a Type II system with a full charge of less than 200 lbs, using recovery equipment manufactured after November 15, 1993?

Accepted Answer

Evacuate to 4 inches of mercury vacuum

Answer

For Type II systems with a refrigerant charge of less than 200 lbs, EPA requires recovery until the system reaches at least 4 inches of mercury (Hg) vacuum using certified equipment made after November 15, 1993. Systems with charges over 200 lbs require a deeper 15 Hg vacuum. Proper evacuation levels ensure maximum refrigerant capture before opening the system.

Question 2

In a Type II refrigeration system, what is superheat and why is it important?

Accepted Answer

The temperature rise of suction gas above its saturation temperature; it ensures only vapor enters the compressor

Answer

Superheat is the temperature of the suction gas above its saturation (boiling) point at a given pressure. Proper superheat ensures that all refrigerant has fully evaporated before entering the compressor, preventing liquid refrigerant from reaching the compressor (liquid slugging). Insufficient superheat risks compressor damage; excessive superheat reduces system efficiency.

Question 3

A rooftop unit charged with R-410A shows high subcooling at the liquid line. What does this most likely indicate?

Accepted Answer

The system is overcharged with refrigerant

Answer

High subcooling (liquid refrigerant cooled significantly below saturation temperature) typically indicates an overcharged system. Excess refrigerant floods the condenser, increasing the liquid subcooling. Undercharge typically causes low subcooling and high superheat. Diagnosing subcooling and superheat together is the proper method for evaluating charge level in high-pressure systems.

Question 4

What is the function of a crankcase heater on a Type II reciprocating compressor?

Accepted Answer

To keep the compressor oil warm during the off-cycle, preventing refrigerant migration into the oil

Answer

During the compressor off-cycle, refrigerant can migrate to the crankcase and dissolve into the compressor oil, creating a refrigerant-oil mixture. When the compressor starts, this mixture can flash (boil rapidly), causing oil foaming, liquid slugging, and bearing damage. The crankcase heater keeps oil warm enough to prevent refrigerant migration, protecting the compressor during startup.

Question 5

When using a manifold gauge set on a Type II high-pressure system, what does a higher-than-normal suction pressure combined with lower-than-normal discharge pressure most likely indicate?

Accepted Answer

Compressor valve failure (worn or broken valves)

Answer

High suction pressure combined with low discharge pressure is a classic sign of compressor valve failure. Worn or broken compressor valves allow refrigerant to bypass from the high side back to the low side, reducing compression efficiency. The compressor cannot build proper pressure difference, resulting in high suction / low discharge readings and poor cooling performance.

EPA 608 609 Practice Test

EPA 608 609 Practice Test

EPA 608 Type II Practice Test 2