Questions With Correct Verified Answers & Explanations
INTRODUCTION
Welcome to the ultimate preparation resource for the EPA Section 608
Type III Certification Exam. This comprehensive study guide features 200
meticulously curated, high-yield multiple-choice questions. It specifically
targets the maintenance, service, repair, and disposal of low-pressure
appliances, such as centrifugal chillers utilizing R-11, R-123, and R-
1233zd.To maximize your study efficiency and exam readiness, every
single question is immediately followed by its VERIFIED ANSWER and a
detailed, bold-italicized EXPLANATION. This instant-feedback structure is
engineered to reinforce critical technical concepts, clarify strict EPA
regulatory thresholds, and eliminate guesswork. Whether you are a
college student pursuing an HVAC/R degree, an apprentice entering the
commercial sector, or a seasoned technician looking to secure your card
on the first try, this document serves as your definitive roadmap to a
perfect score.
Question 1
Type III technicians primarily work on which type of appliances?
A. Small appliances containing less than 5 pounds of refrigerant
,B. High-pressure and very high-pressure appliances
C. Low-pressure appliances, such as centrifugal chillers
D. Motor vehicle air conditioning systems
Verified Answer: C
Explanation: Type III certification under EPA Section 608 specifically
permits a technician to service or repair low-pressure appliances,
which typically include large commercial or industrial centrifugal
chillers using refrigerants like R-11, R-113, or R-123.
Question 2
Which of the following refrigerants is classified as a low-pressure
refrigerant under EPA Section 608?
A. R-22
B. R-123
C. R-134a
D. R-410A
Verified Answer: B
Explanation: R-123 is a Hydrochlorofluorocarbon (HCFC) that
operates at low pressure, meaning its liquid phase has a boiling
point above 68°F at atmospheric pressure. It replaced R-11 in low-
pressure centrifugal applications.
Question 3
What is the primary way that moisture typically enters a low-pressure
chiller system?
A. Contaminated refrigerant recharging cylinders
,B. Chemical breakdowns of internal compressor oil
C. Air leaks from areas with gaskets, seals, or fittings
D. Condensation forms within the purge unit collection chamber
Verified Answer: C
Explanation: Because low-pressure systems operate under a
vacuum (below atmospheric pressure) on the low side, external
ambient air and moisture will migrate into the system through any
compromised gaskets, O-rings, or structural fittings.
Question 4
When leak testing a low-pressure centrifugal chiller, what is the maximum
safe test pressure to avoid damaging structural components?
A. 10 psig
B. 25 psig
C. 50 psig
D. 150 psig
Verified Answer: A
Explanation: Low-pressure chillers are designed with lightweight
vessels. Exceeding 10 psig during a leak test risks structurally
buckling or bursting the evaporator shells or blowing the standard
15 psig safety rupture disc.
Question 5
What is the standard activation or burst pressure of the rupture disc on a
low-pressure centrifugal chiller?
A. 10 psig
, B. 15 psig
C. 30 psig
D. 50 psig
Verified Answer: B
Explanation: Rupture discs on low-pressure chillers serve as the
primary over-pressurization safety device. They are engineered to
burst completely open at exactly 15 psig to prevent catastrophic
shell failure.
Question 6
To safeguard the system during leak testing, where is the rupture disc on
a low-pressure chiller typically located?
A. On the liquid line leaving the condenser
B. On the evaporator shell or the compressor suction line
C. Directly on the discharge port of the purge unit
D. In line with the oil separator assembly
Verified Answer: B
Explanation: The rupture disc is located on the low-pressure side of
the machine, typically on the evaporator shell, to shield the large,
low-pressure vessel surfaces from accidental over-pressurization.
Question 7
Under EPA regulations, what is the preferred method to safely pressurize
a low-pressure chiller for non-major leak detection and repair?
A. Injecting high-pressure compressed shop air
B. Charging liquid R-22 to increase systemic pressure