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Flashcards in EPA Test Prep 2- Type 3 Deck (25)
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1

When leak testing a low pressure centrifugal with nitrogen, what is the maximum test pressure?
A. 0 psig
B. 10 psig
C. 25 psig
D. 50 psig

B. 10 psig

2

Charged low pressure refrigeration machines may be most efficiently checked by:
A. Adding dry nitrogen
B. Adding HCFC 22
C. Raising system pressure by heating with circulated hot water or heating blankets
D. Operating the purge system

C. Raising system pressure by heating with circulated hot water or heating blankets

3

EPA regulations require that all appliances containing more than 50 lbs of refrigerant (except for commercial and industrial process refrigeration) be repaired when the leak rate exceeds_______ % of the charge per year
A. 0
B. 15
C. 25
D. 35

B. 15

4

A typical setting for the high pressure cut-out control on a recovery unit used for evacuating the refrigerant from a low pressure chiller is:
A. 2 psig
B. 5 psig
C. 10 psig
D. 15 psig

C. 10 psig

5

R 11 or R 123 system refrigerant removal starts with:
A. Vapor removal
B. Liquid removal
C. Vapor and liquid removal
D. Oil separation

B. Liquid removal

6

With a low pressure chiller, what must you do after recovering the liquid refrigerant?
A. Recover the vapor refrigerant
B. Pressurize system with nitrogen
C. Remove the oil from the system
D. Solvent flush entire system

A. Recover the vapor refrigerant

7

When removing oil from a low pressure system, the temperature should be 130F because:
A. You can warm your hands on the container
B. Less refrigerant will be contained in the oil at the higher temperature
C. Warmer oil has a lower viscosity and flows more easily
D. It shows that the heater is working

B. Less refrigerant will be contained in the oil at the higher temperature

8

According to ASHRAE guideline 3-1996, if the pressure in a system rises from 1mm hg to a level above______ during a standing vacuum test, the system should be checked for leaks.
A. 1.5 mm hg
B. 2.0 mm hg
C. 2.5 mm hg
D. 3.0 mm hg

C. 2.5 mm hg

9

After system servicing, why is refrigerant vapor re-introduced to the refrigeration system before refrigerant liquid?
A. Vapor charging increases pressure slowly, preventing failure of the rupture disk
B. Vapor charging is faster than liquid charging
C. Liquid charging is more difficult to control than vapor charging
D. Liquid charge into a deep vacuum will boil and may lower temperatures enough to freeze water in the tubes

D. Liquid charge into a deep vacuum will boil and may lower temperatures enough to freeze water in the tubes

10

Appliances need not be evacuated all the way to the prescribed level when:
A. The repair is major
B. The repair is followed by an evacuation of the appliance to the environment
C. Leaks in the appliance make evacuation to the prescribed level unattainable
D. The appliance is being disposed

C. Leaks in the appliance make evacuation to the prescribed level unattainable

11

Which of the following repairs would ALWAYS be considered "major" under EPA's regulations?
A. Replacement of an evaporator coil
B. Replacement of a drier filter
C. Replacement of a switch
D. Replacement of a purge unit

A. Replacement of an evaporator coil

12

After reaching the required recover vacuum on an appliance, you should:
A. Immediately disconnect the recycling or recovery equipment and open the system for service
B. Wait for at least a few minutes to see if the system pressure rises, indicating that there is still refrigerant in liquid form or in the oil
C. Immediately break the vacuum with nitrogen and open the system for service
D. Immediately pressurize the system with nitrogen and perform a leak check

B. Wait for at least a few minutes to see if the system pressure rises, indicating that there is still refrigerant in liquid form or in the oil

13

Which of the following WOULD NOT fall under the EPA definition for "Major maintenance -service -or repair"?
A. Replacing an oil
B. Replacing the compressor
C. Re-tubing a heat exchanger (condenser)
D. Replacing a fin and tube forced air evaporator coil

A. Replacing an oil filter

14

When using recovery or recycling equipment manufactured BEFORE Nov 15th, 1993, technicians must evacuate low pressure appliances to the following level before making a major repair:
A. 0 psig
B. 15 inches hg vacuum
C. 25 inches hg vacuum
D. 25 mm hg absolute

C. 25 inches hg vacuum

15

Under EPA's regulations, which of the following methods can be used to pressurize an R11 or R123 system for the purpose of opening the system for a non-major repair?
A. Adding nitrogen
B. Warming the refrigerant
C. Adding compressed air
D. Adding carbon dioxide

A. Adding nitrogen

16

During vapor removal from a low pressure refrigeration system:
A. The system water pumps should be on, and the recovery compressor should be off
B. The system water pumps should be on, the recovery compressor should be on, and the recovery condenser water should be off
C. The water pumps, the recovery compressor, and the recovery condenser water should all be on
D. The system water pumps should be off, and the recovery compressor should be on

C. The water pumps, the recovery compressor, and the recovery condenser water should all be on

17

The PRIMARY purpose of a purge pump unit on a CFC 11 chiller is to:
A. Remove CFC's from the system
B. Condense air out of the system
C. Condense water out of the system
D. Remove non-condensable from the system

D. Remove non-condensable from the system

18

Under what code group of ASHRAE standard 34 does R123 fall?
A. A1
B. A2
C. B1
D. B2

C. B1

19

Which of the following safety precautions should be adhered to for low pressure systems?
A. Do not siphon refrigerant by mouth
B. Avoid spilling liquid refrigerant on the skin
C. Use gloves and safety googles when working with liquid refrigerant
D. All of the above

D. All of the above

20

When recharging a refrigeration system with R11, what vapor pressure is necessary in the shells before charging with liquid?
A. 21.1 inches hg vacuum
B. 19,7 inches hg vacuum
C. 18.1 inches hg vacuum
D. 16.9 inches hg vacuum

D. 16.9 inches hg vacuum

21

A centrifugal chiller's rupture disk is connected to the chillers:
A. Condenser
B. Evaporator
C. Liquid line
D. Economizer

B. Evaporator

22

On a centrifugal system, the purgeunit takes its suction from the:
A. Top of the condenser
B. Compressor oil dump
C. Top of the evaporator
D. Suction elbow

A. Top of the condenser

23

A rupture disk on a recovery vessel for low pressure refrigerants relieves at:
A. 5 psig
B. 10 psig
C. 15 psig
D. 20 psig

C. 15 psig

24

Approximately how much refrigerant vapor is left in an average 350 ton R11 chiller at 0 psig pressure once all of the R11 liquid has been removed?
A. None
B. 5 lbs
C. 20lbs
D. 100lbs

D. 100lbs

25

What is the primary water source for a recovery unit condensing coil?
A. Chilled water
B. Condenser water
C. Local municipal supply
D. De-ionized water

D. De-ionized water