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Hvac > EPA Test Prep 2 Type 2 > Flashcards

EPA Test Prep 2 Type 2 Flashcards

1
Q

When first inspecting a hermetic system known to be leaking, you should look for:

A. Frost on the tubing
B. Puddles of refrigeration
C. Particle of filter drier core
D. Traces of oil

A

D. Traces of oil

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2
Q

Many refrigeration units use an open compressor, which part of the compressor is most likely to leak if a unit is not used for several months?

A. The suction service valve
B. The rotating shaft seal
C. The oil drain plug
D. The discharge service valve

A

B. The rotating shaft seal

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3
Q

EPA regulations require that all appliances containing more than 50 pounds of refrigerant (except for commercial and industrial process refrigeration) be repaired when the leak rate exceeds ______ percent of the charge per year.

A.0
B.15
C.25
D.35

A

B.15

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4
Q

With an air cooled condenser on the roof of a building and the evaporator on the first floor, recovery should first occur:
A. From the vapor line entering the condenser
B. From the discharge of the compressor
C. From the liquid line entering the evaporator
D. On the suction side of the compressor

A

C. From the liquid line entering the evaporator

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5
Q

Gauges set hoses used for field service work should have self-sealing connectors or hand valves in order to:
A. Minimize the chance of an explosion during refrigerant recovery
B. Prevent venting during recycling
C. Minimize refrigerant release when hoses are connected and disconnected
D. Prevent vapor lock during liquid transfer

A

C. Minimize refrigerant release when hoses are connected and disconnected

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6
Q

Recycling or recovery equipment using hermetic compressors has the potential to overheat when drawing deep vacuum because:
A. It runs faster than other equipment
B. The motor relies on the flow of refrigerant through the compressor for cooling
C. It has a higher compression ratio than other equipment
D. The oils used in hermetic compressors at lower temperatures than the oils used in other equipment
E. Fuck Ben

A

B. The motor relies on the flow of refrigerant through the compressor for cooling

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7
Q 
When using recovery and recycling equipment manufactured AFTER Nov 15th, 1993 technicians must evacuate an appliance component containing MORE than 200lbs of CFC 12 to the following level before making a major repair:
A. 0 psig 
B. 4 inches hg vacuum 
C. 10 inches hg vacuum 
D. 15 inches hg vacuum
A

D. 15 inches hg vacuum

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8
Q

In general, what is one routine maintenance task which must be performed on most refrigerant recycling machines?

A) check compressor seals
B) change electrical fuses
C) change oil filter
D) replace moisture sight glass

A

C) change oil and filter

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9
Q

You can save time recovering the refrigerant from a system by removing as much as possible in the _______ phase?

A) final
B) initial
C) liquid
D) vapor

A

C) liquid

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10
Q

Your recovery/recycling machine has R502 refrigerant in it. You now have to recover refrigerant from a unit with R22. What must be done before the R22 refrigerant can be recovered/recycled?

A) nothing, as long as the recovery machine is not full
B) change the expansion valve on the recovery machine
C) recover as much of the R502 from the recovery unit as possible, change filter, and evacuate

A

C) recover as much of the R502 from the recovery unit as possible, change filter, and evacuate

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11
Q

When using recovery and recycling equipment manufactured BEFORE Nov. 15, 1993 technicians must evacuate an appliance containing 10 pounds of CFC 500 to the following level before disposing of the appliance

A) 0 psig
B) 4 inches Hg vacuum
C) 10 inches Hg vacuum
D) 15 inches Hg vacuum

A

B) 4 inches Hg vacuum

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12
Q 
The state of the refrigerant leaving the receiver of a refrigeration system is: 
A. Low pressure liquid 
B. Low pressure vapor 
C. High pressure liquid 
D. High pressure vapor
A

C. High pressure liquid

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13
Q

A reciprocating compressor should not be energized when:
A. The discharge service valve is closed
B. The suction service valve is open
C. The discharge service valve is open
D. There is a demand for cooling

A

A. The discharge service valve is closed

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14
Q 
Which of the following is an indicator of a leak in high pressure system? 
A. High head pressure 
B. Low water temperature 
C. Excessive superheat 
D. Frequent purging
A

C. Excessive superheat

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15
Q 
The evaporation temperature of the R 134a at 0 psig is: 
A. -21 degrees F
B. -15 degrees F 
C. -5 degrees F
D. -1 degree F
A

B. -15 degrees F

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16
Q 
Every refrigerating system shall be protected by: 
A. A pressure relief valve device 
B. A properly located stop valve 
C. A low pressure control 
D. A refrigerant receiver
A

A. A pressure relief valve device

17
Q

An operating unit that has a receiver/ storage tank requires refrigerant system service. When servicing the unit:
A. The compressor should be calves off
B. Liquids should be recovered last
C. Refrigerant should be recovered in the receiver
D. A gauge pressure should be achieved by venting

A

C. Refrigerant should be recovered in the receiver

18
Q 
Refrigerant should be removed from the condenser outlet when:
A. The condenser is below the receiver 
B. The condenser is on the roof 
C. The compressor is inoperative
D. The evaporator has a small leak
A

A. The condenser is below the receiver

19
Q 
You are going to service a residential split system, providing comfort air conditioning. You would expect to find what type of refrigerant? 
A. R502 
B. R22
C. R11
D. R12
A

B. R22

20
Q

Which of the following statements is NOT true of recycling and recovery equipment manufactured after Nov 15th, 1993?
A. It must be tested by an EPA approved third party
B. It must meet vacuum standards more stringent than those met by equipment manufactured before Nov 15th, 1993
C. It must be equipped with low loss fittings
D. It must have an oil separator

A

D. It must have an oil separator

21
Q

After reaching the required recovery vacuum on an appliance you should:

A) immediately disconnect the recycling 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

A

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

22
Q

Which of the following repairs would ALWAYS be considered “major” under EPA regulations?

A) replacement of an evaporator coil
B) replacement of a filter drier
C) replacement of a schrader valve core
D) replacement of a condenser fan motor

A

A) replacement of an evaporator coil

23
Q

Appliances containing CFC refrigerants can be evacuated to atmospheric pressure 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 evacuations to the prescribed level unattainable
D) the appliance is being disposed

A

C) leaks in the appliance make evacuations to the prescribed level unattainable

24
Q

You are changing out the compressor of a system containing 40 pounds of R502. Your recycling equipment was manufactured AFTER Nov. 15, 1993. In addition to isolating the compressor as much as possible, which of the following procedures should you follow?

A) simply remove the compressor
B) evacuate the isolated section of the system to atmospheric pressure, then remove the compressor
C) evacuate the isolated section of the system to 10 inches of vacuum and hold. If the pressure does not rise, remove the compressor
D) evacuate the isolated section of the system to 15 inches of vacuum and hold. If the system pressure does not rise, remove the compressor

A

C) evacuate the isolated section of the system to 10 inches of vacuum and hold. If the pressure does not rise, remove the compressor

25
Q

Recovering refrigerant from a system in vapor phase will minimize loss of:

A) water
B) oil
C) refrigerant
D) all of the above

A

B) oil

Hvac (18 decks)

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