Information on Low-Pressure Practice Test 1
This is the first in a series of free practice tests on handling refrigerants in low-pressure appliances and servicing low-pressure equipment. These practice tests are among the best mobile-friendly tests on the web and render great on phones and tablets for students and apprentices on the go. Please consider sharing our tests with others that may find them useful, individually or in forums.
* NOTE: Having a pressure-temperature reference for commonly used refrigerants is required to answer some of the questions on our practice tests unless you have an amazing memory.
- This Low-Pressure practice test is free. Take it as often as you like.
- Contains 25 questions.
- Pressing the submit button immediately returns your resulting score.
- Passing score is 70%. (18 out of 25)
- Correct answer information is provided for questions answered incorrectly.
- Good luck!
| Trade Category: | HVACR |
| Test Category: | EPA 608 Certification |
| Test Subject: | Type III (Low-Pressure) |
| Test Number: | 1 of 3 |
| Questions on Test: | 25 |
| Passing Score: | 70% |
#1. A typical setting for the high-pressure cut-out control on a recovery unit used for evacuating refrigerant from a low-pressure chiller is
Correct answer is C: 10 psig
A typical setting for the high-pressure cut-out control on a recovery unit used for evacuating refrigerant from a low-pressure chiller is 10 psig
#2. A charged low pressure refrigeration system can be efficiently leak-checked by
Correct answer is D: raising system pressure by heating with circulated hot water or heating blankets.
A charged low pressure refrigeration system can be efficiently leak-checked by raising system pressure by heating with circulated hot water or heating blankets.
#3. The existence of air in a low pressure system causes
Correct answer is C: high head pressure.
The existence of air in a low pressure system causes high head pressure.
#4. Which safety precaution should be adhered to for low pressure systems?
Correct answer is D: All of the above.
The following safety precautions should be adhered to for low pressure systems:
- Do not siphon refrigerant by mouth .. dummy.
- Avoid spilling liquid refrigerant on your skin.
- Use gloves and safety goggles when working with liquid refrigerant.
#5. Refrigerant-11 (R-11) at 14.7 psia, will boil at about
Correct answer is B: 74.5 F
Refrigerant-11 (R-11) at 14.7 psia, will boil at about 74.5 F.
#6. When there is excessive moisture collecting in the purge unit of a low pressure refrigeration system, this indicates that
Correct answer is B: the condenser or chiller barrel tubes are leaking.
When there is excessive moisture collecting in the purge unit of a low pressure refrigeration system, this indicates that the condenser or chiller barrel tubes are leaking.
#7. ASHRAE Standard 15-1994 requires equipment room refrigerant sensors for what safety group classification?
Correct answer is D: All refrigerant safety groups.
ASHRAE Standard 15-1994 requires equipment room refrigerant sensors for all refrigerant safety group classifications.
#8. When recharging a refrigeration system with R-11, what vapor pressure is necessary in the shells before charging with liquid?
Correct answer is D: 16.9 inch Hg vacuum
When recharging a refrigeration system with R-11, what vapor pressure is necessary in the shells before charging with liquid? 16.9 inch Hg vacuum
#9. After reaching the required recovery vacuum on a chiller, you should
Correct answer is B: wait for at least a few minutes to see if the system pressure rises, indicating there is still refrigerant in liquid form or in the oil.
After reaching the required recovery vacuum on a chiller, you should wait for at least a few minutes to see if the system pressure rises, indicating there is still refrigerant in liquid form or in the oil.
#10. A hydrostatic tube test kit is used to
Correct answer is D: determine if a tube leaks.
A hydrostatic tube test kit is used to determine if a tube leaks.
#11. When charging a chiller, refrigerant vapor is introduced into the system before charging with liquid refrigerant. This is because
Correct answer is D: liquid charged into a deep vacuum will cause the refrigerant to boil and may lower temperatures enough to freeze the water in the tubes.
When charging a chiller, refrigerant vapor is introduced into the system before charging with liquid refrigerant. This is because liquid charged into a deep vacuum will cause the refrigerant to boil and may lower temperatures enough to freeze the water in the tubes.
#12. When evacuating a system, the use of too large a vacuum pump can cause
Correct answer is A: trapped water to freeze.
When evacuating a system, the use of too large a vacuum pump can cause trapped water to freeze.
#13. On a low pressure chiller with an open-type compressor, the _________ is/are very susceptible to leaks.
Correct answer is B: shaft seal
On a low pressure chiller with an open-type compressor, the shaft seal is very susceptible to leaks.
#14. What steps may be taken to prevent air accumulation into an idle low-pressure refrigeration system?
Correct answer is B: System pressure should be maintained slightly above atmospheric pressure.
What steps may be taken to prevent air accumulation into an idle low-pressure refrigeration system? System pressure should be maintained slightly above atmospheric pressure.
#15. Commercial and industrial process refrigeration systems must be repaired when the leak rate exceeds ______ percent of the charge per year.
Correct answer is D: 30 percent
Commercial and industrial process refrigeration systems must be repaired when the leak rate exceeds 30 percent percent of the charge per year.
THIS BECAME EFFECTIVE JAN 2019: Leak rates, documentation, and inspection parameters changed. The new leak thresholds are now:
- 30% for Industrial Process Refrigeration
- 20% for Commercial Refrigeration
- 10% for Comfort Cooling
PREVIOUS THRESHOLDS:
- 35% for Industrial Process Refrigeration
- 35% for Commercial Refrigeration
- 15% for Comfort Cooling
#16. When recovering vapor from a low pressure refrigeration system,
Correct answer is C: the system water pumps, the recovery compressor, and the recovery condenser water should all be on.
When recovering vapor from a low pressure refrigeration system, the system water pumps, the recovery compressor, and the recovery condenser water should all be on.
#17. Where does refrigerant go after it leaves the purge unit of a low pressure centrifugal system?
Correct answer is A: The evaporator
Where does refrigerant go after it leaves the purge unit of a low pressure centrifugal system? The evaporator.
#18. The purge unit takes its suction from the
Correct answer is A: top of the condenser.
The purge unit takes its suction from the top of the condenser.
#19. Which of the following repairs would ALWAYS be considered a “major” repair unde EPA’s regulations?
Correct answer is A: Replacement of an evaporator coil.
Which of the following repairs would ALWAYS be considered a “major” repair unde EPA’s regulations? Replacement of an evaporator coil.
#20. Charging liquid refrigerant into a refrigeration system when it is under a 29-inch Hg vacuum can cause the
Correct answer is C: system water to freeze.
Charging liquid refrigerant into a refrigeration system when it is under a 29-inch Hg vacuum can cause the system water to freeze.
#21. According to the EPA there is approximately ________ of refrigerant vapor left in an average 350 ton R-11 chiller at 0 psig pressure once all the R-11 liquid has been removed.
Correct answer is D: 100 lbs
According to the EPA there is approximately 100 lbs of refrigerant vapor left in an average 350 ton R-11 chiller at 0 psig pressure once all the R-11 liquid has been removed.
#22. An oil sample should be taken when
Correct answer is B: there has been a compressor burnout.
An oil sample should be taken when there has been a compressor burnout.
#23. Both CFC-11 and HCFC-123 chillers require purge units because
Correct answer is B: the system operates below atmospheric pressure.
Both CFC-11 and HCFC-123 chillers require purge units because the system operates below atmospheric pressure.
#24. Refrigerant recovery typically starts with __________ because it is faster.
Correct answer is B: liquid recovery
Refrigerant recovery typically starts with liquid recovery because it is faster.
#25. Under EPA regulations, _________ is used to pressurize a low-pressure chiller for the purpose of opening the system for a non-major repair.
Correct answer is B: warming the refrigerant
Under EPA regulations, warming the refrigerant is used to pressurize a low-pressure chiller for the purpose of opening the system for a non-major repair.
More Type 3 Low-Pressure Practice Tests
Type 3 Test 1
Type 3 Test 2
Type 3 Test 3
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