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EPA 608 NEC 2023

EPA 608 Type 3 Exam Practice Test 6

Free EPA 608 Type III Exam Practice Test 6. 25 questions covering purge compressor location on condenser, maximum leak test pressure of 10 PSIG, hydrostatic tube test for water-side leaks, purge unit removing non-condensables, rupture disk name and function, rupture disk relief pressure 15 PSIG, low-pressure system below atmospheric operation, 50 lb exemption from mandatory repair, 35% commercial refrigeration threshold, nitrogen purging not permitted with refrigerant in system, R-11 classification and phase-out, R-123 as HCFC replacement, Type III technician servicing low-pressure equipment, centrifugal chiller component identification, R-245fa long-term HFC replacement, oil degas procedure, EPA 25 mm Hg recovery requirement, rupture disk event and replacement, comfort cooling vs commercial refrigeration thresholds, ASHRAE Standard 15 exterior signage, alkylbenzene oil and R-123 compatibility, surge prevention methods, electronic leak detection for R-11 and R-123, centrifugal compressor no valves, and EPA Section 608 owner and technician responsibilities.

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The EPA 608 certification is required by law for any technician who purchases or handles refrigerants. It covers safe handling, leak detection, recovery, and environmental regulations.

Type I covers small appliances (≤5 lbs refrigerant), Type II covers high-pressure systems, Type III covers low-pressure systems, and Universal covers all three. Most HVAC technicians pursue Universal certification.

You must score at least 70% on each section of the exam. The Universal exam has four parts: core, Type I, Type II, and Type III.

Key facts for this test: The purge compressor is typically mounted on top of the condenser where non-condensables collect. The maximum pressure for leak testing a low-pressure system is 10 PSIG. A hydrostatic tube test uses water pressure to detect tube-side leaks in condensers and evaporators. The rupture disk is the safety device that releases at 15 PSIG to prevent catastrophic overpressure. Low-pressure systems operate below atmospheric pressure — any leak draws air in.

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EPA 608 Type 3 Exam Practice Test 6 — Question List

Question 1: The purge compressor is typically connected on top of ………………. In low pressure chiller refrigeration system.

Condenser
Oil separator
Chiller
Purge drum

Question 2: For leak testing a low pressure refrigeration system what is the maximum pressure that can be applied?

10 psig
5 psig
15 psig
20 psig

Question 3: A hydro static tube test is conducted on low pressure refrigeration system to detect

Expansion leakage
Water tube leakage
Compressor leakage
Evaporator leakage

Question 4: A unit which removes non-condensables present in the refrigeration system from the top of the condenser is called as :……….

Purge unit
Hydrostatic unit
Pressurizer
Filter

Question 5: When the pressure in the low pressure refrigeration equipment increases, the disk which releases the pressure is called as :………….

Rupture disk
Bursting risk
Pressure disk
Relief disk

Question 6: What is the rupture disk relief pressure in the low pressure refrigeration system?

10 psig
15 psig
20 psig
18 psig

Question 7: Low pressure refrigeration system will operate at …………..

Below atmospheric pressure
Above atmospheric pressure
More than 15 psig pressure
Lower than 15 psig pressure

Question 8: The leaks in a refrigeration system contains ……………. refrigerant need not be repaired as per EPA.

Less than 50 pounds
Greater than 50 pounds
Less than 100 pounds
Greater than 100 pounds

Question 9: In commercial and industrial refrigeration systems, if the leak percentage increases more than ………….. of the charge per year must be removed.

30 %
35 %
50 %
15 %

Question 10: A nitrogen purging test can be performed on refrigeration system with refrigerant.

False
True

Question 11: R-11 is still found in many older centrifugal chillers despite its production being banned. What classification is R-11, when was production banned, and what is the only legal source of R-11 today?

R-11 is an HFC; production continues but is regulated; can be purchased in any quantity
R-11 is a CFC; production was banned December 31, 1995; only reclaimed R-11 meeting AHRI 700 purity is legally available today
R-11 is an HCFC; it can still be manufactured under special EPA permit for existing chiller maintenance
R-11 is a natural refrigerant; it was not banned but production was voluntarily discontinued

Question 12: Why is R-123 classified as an HCFC and not an HFC, and how does this classification affect its long-term regulatory status?

R-123 is classified as HFC because it replaced an HFC refrigerant in chiller applications
R-123 is HCFC because it contains one chlorine atom — giving it ODP=0.02 and placing it under the Montreal Protocol HCFC phase-down schedule
R-123 is HCFC but this classification has no regulatory effect in the United States
R-123 is classified as CFC because it replaced R-11, another CFC refrigerant

Question 13: A Type III certified technician is called to service an R-22 high-pressure rooftop unit. Can this technician legally perform the service?

Yes — all EPA 608 certifications allow the technician to service any type of refrigeration equipment
No — Type III covers only low-pressure systems; servicing R-22 requires Type II or Universal certification
Yes — as long as the technician passes a simple refresher exam for R-22
Only if the R-22 system is over 50 lbs charge — smaller systems do not require matching certification type

Question 14: In a centrifugal chiller, what is the function of the condenser and where is it located in relation to the compressor?

The condenser is where refrigerant evaporates — it is located between the expansion device and the compressor
The condenser receives hot refrigerant vapor from the compressor; condenser water absorbs heat and causes refrigerant vapor to condense into liquid
The condenser is where refrigerant is compressed — it is the main working component of the chiller
The condenser removes moisture from refrigerant using a desiccant filter

Question 15: A chiller manufacturer is designing a new centrifugal chiller model intended to be in service until 2050. They choose R-245fa instead of R-123. What is the primary regulatory reason?

R-245fa is chosen because it operates at higher pressure than R-123 — easier to detect leaks
R-245fa has zero ODP as an HFC — not subject to Montreal Protocol HCFC phase-down that restricts R-123, making it available throughout the chiller's intended 2050 service life
R-245fa is cheaper to produce than R-123 — the decision is purely economic
R-245fa does not require EPA certification — this reduces service costs over the chiller life

Question 16: During a routine oil change on an R-123 centrifugal chiller, the technician notices the drained oil is foaming and bubbling. What does this indicate?

The oil has gone acidic and is chemically reacting with oxygen — it must be disposed of as hazardous waste immediately
The oil was not heated to 100°F before draining — dissolved refrigerant is flashing out as the cold oil is exposed to atmospheric pressure
The oil is completely normal — AB oil always foams when drained from R-123 systems
The oil heater failed during operation, causing the refrigerant to condense into the oil in liquid form

Question 17: When measuring vacuum for EPA required recovery of a low-pressure chiller, why is a micron gauge required rather than a standard manifold gauge?

A micron gauge is only required for Type II systems — manifold gauges are acceptable for Type III
Standard manifold gauges cannot accurately read deep vacuum; a micron gauge measures in absolute units (microns of mercury) with the precision needed to verify the 25 mm Hg EPA requirement
Micron gauges are used because they measure in metric units — manifold gauges only read in imperial units
A micron gauge measures refrigerant purity — it detects air and moisture in the system

Question 18: After a rupture disk on an R-123 chiller bursts, a technician installs a new rupture disk rated at 20 PSIG instead of the required 15 PSIG. Why is this dangerous?

A 20 PSIG disk is actually safer because it takes more pressure to burst — this protects the system better
A 20 PSIG disk will not burst until 20 PSIG — by then the evaporator shell may exceed its design limits, risking catastrophic shell failure
All rupture disks are interchangeable — pressure rating does not matter as long as the diameter fits
There is no danger — the chiller's high-pressure safety cutout will prevent pressure from reaching 20 PSIG

Question 19: A technician services both R-22 supermarket refrigeration cases (commercial refrigeration) and R-123 centrifugal chillers (comfort cooling HVAC). Which application has the stricter annual leak rate threshold?

The commercial refrigeration cases have the stricter threshold — food safety requires lower leak rates
The R-123 centrifugal chiller (comfort cooling) has the stricter 15% threshold; commercial refrigeration has the more lenient 35% threshold
Both applications have the same threshold — EPA does not differentiate between comfort cooling and commercial refrigeration
R-22 has the stricter threshold because it is an HCFC — refrigerant type determines the threshold

Question 20: According to ASHRAE Standard 15, what must be installed inside a mechanical room containing R-123 centrifugal chillers to automatically protect personnel from refrigerant exposure?

A sprinkler system — to suppress refrigerant fires if ignition occurs
A refrigerant detector that automatically activates audible alarm and emergency exhaust ventilation when refrigerant is detected above the setpoint
A carbon monoxide detector — CO from refrigerant decomposition is the main hazard in chiller rooms
A manual emergency stop switch — automatic systems are not required, only manual controls

Question 21: What would happen if POE (polyolester) oil — typically used in R-410A HFC systems — were accidentally added to an R-123 centrifugal chiller that requires alkylbenzene (AB) oil?

Nothing would happen — all synthetic oils are interchangeable in refrigeration systems
POE oil is very hygroscopic; in an R-123 system it would absorb moisture aggressively, increasing acid formation risk and potentially causing deposit issues
POE oil would improve R-123 system performance — it has better heat transfer than AB oil
POE oil would immediately damage the compressor bearings because it is not lubricating enough for centrifugal compressors

Question 22: Which THREE methods are commonly used to prevent centrifugal chiller surge at low load conditions?

Increasing condenser water flow, reducing chilled water setpoint, and adding more refrigerant
Hot gas bypass (artificial load), variable inlet guide vanes (flow modulation), and variable frequency drive (speed reduction)
Increasing motor speed, installing a larger impeller, and adding a suction accumulator
Stopping the chiller, adding refrigerant charge, and restarting at full speed

Question 23: An electronic leak detector is being used to check a partially pressurized (5 PSIG nitrogen added) R-11 centrifugal chiller. Where on the chiller should the technician concentrate the search, starting from the most likely leak locations?

Start at the condenser tubes — leaks always begin at the highest pressure point
Start at shaft seals (most common), then tube sheet gaskets, purge unit connections, and sight glass fittings
Start at the refrigerant recovery connection — leaks always occur at the most recently disturbed point
Scan the entire room first — electronic detectors work best from a distance of 3–4 feet

Question 24: Why does the absence of suction and discharge valves in a centrifugal compressor make it MORE reliable than a reciprocating compressor, but also create the risk of surge?

The absence of valves allows the compressor to run cooler — reducing maintenance but also reducing cooling capacity
No valves means no valve wear or failure (higher reliability), but also nothing prevents refrigerant backflow at low loads (surge risk)
Centrifugal compressors without valves cannot build sufficient pressure — they are only used for pre-cooling before a reciprocating compressor
The lack of valves is a design flaw — centrifugal compressors should have discharge valves but manufacturers omit them to reduce cost

Question 25: A service technician discovers that a 1,200 lb R-123 chiller is leaking at 25% per year. The building owner says "just keep topping it off — we cannot afford a repair right now." What must the technician do?

Add the refrigerant as instructed — the owner pays the bills and makes all decisions
Inform the owner in writing that the 25% leak rate exceeds the 15% mandatory repair threshold and that repair within 30 days is required by law
Recover all refrigerant immediately without owner authorization and shut the chiller down
Report the owner to the EPA immediately without speaking to them first

Study Tip: The EPA 608 exam is closed book. Memorize: recovery is required before opening any refrigerant system. Venting refrigerant is illegal. Know the ODP and GWP values for R-22, R-410A, R-134a, R-32, and R-454B.

EXAM CARD EPA 608

Questions25

Time limit45 min

Pass score70%

RegulationEPA Section 608

DifficultyIntermediate

Last reviewedJun 2026

Timer starts immediately. Progress is auto-saved.

Source: EPA Section 608 (40 CFR Part 82)