Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Epa > Epa Type 2 > Flashcards

Epa Type 2 Flashcards

Equipment

1
Q

In order to recover from a system with parallel compressors, the individual compressors must be isolated. Why?

A

It isolates the refrigerant that must be recovered

from the rest of the system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which refrigerant (s) require and equipment room monitor per ASHRAE Standard 15?

A

All refrigerants.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What protection is mandatory to protect a system against damage from excessive pressure?

A

A pressure relief device.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Are multiple relief valves connected in series or parallel?

A

Parallel.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why is the use of a regulator required when using dry nitrogen?

A

To limit the outlet pressure of the nitrogen cylinder.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Recovering in a vapor phase reduces unwanted loss of what?

A

Oil and unwanted contaminants from the system to

the recovery machine and recovery drum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

On a high-pressure system recovery, should the recovery cylinder be heated or cooled?

A

Cooled.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What must be done to a recovery machine when changing to a different refrigerant?

A

Clean out all residual refrigerant, change oil, replace filters, evacuate machine by pump-out or
another machine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What besides filters must periodically be changed out on a recovery machine?

A

Oil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Recovered refrigerant can contain oil and acids. Name another compound found in refrigerants?

A

Moisture.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the water source for a condensing coil on a water-cooled recovery machine?

A

Municipal water tap.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What access location should you use when recovering from an air-cooled system with its condenser several feet above the evaporator?

A

Suction line.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What access location should you use when recovering from a system with its condenser below the evaporator?

A

Liquid line.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is EPA’s definition of a “major repair”?

A

Any repair that involves the removal of the compressor, evaporator, condenser, or any
auxiliary heat exchanger coil.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Prior to making a major repair, what vacuum level must you pull when using recovery equipment manufactured in 1996 on a unit with 215 lbs. of CFC-12?

A

15 inches of Hg,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What vacuum level must you pull when using recovery equipment manufactured in 1992 when disposing of an appliance containing 12 lbs. of R 500?

A

4 inches of Hg.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Under what circumstances may a technician recover the CFC refrigerant in an appliance to atmospheric pressure only?

A

if leaks are in the system or if recovery to target levels would contaminate the refrigerant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What procedure should be performed on an empty recovery cylinder before it is used for storing recovered refrigerant?

A

It must be evacuated of all non-condensables.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What may legally be done with the refrigerant recovered from a system in order to replace a condenser coil?

A

Reused in the original system or transferred to another system with the same owner after it is checked so that it is free of non-condensables.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

When servicing an operating unit with a receiver, where should the recovery hoses be attached to the unit?

A

To the liquid line.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does “back-seating” a suction valve do?

A

Allows flow through the main line while closing the

access port.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What will non-condensables do to the pressures in a refrigerant circuit?

A

Increase discharge pressure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What causes oil foaming in a system and where does it normally occur?

A

Oil that is mixed with refrigerant will foam in the compressor crankcase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What system failures require taking an oil sample?

A

Compressor burnout or if the unit has had a leak.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

A vacuum pump that is too large can cause what problem?

A

It can cause moisture to freeze in the system?

26
Q

Where is a receiver typically installed on a system?

A

At the outlet of the condenser.

27
Q

What will be the boiling temperature of HFC-134a be at 0 PSIG?

A

-15 degrees F.

28
Q

Is it a requirement that recovery machines contain an oil separator?

A

NO

29
Q

Which refrigerant is typically used on a residential split system air conditioner?

A

HCFC-22.

30
Q

What component is always replaced after a a system is opened for service?

A

Filter-driers.

31
Q

What is the purpose of the moisture indicator in a sight glass?

A

To permit a check of moisture content in the system.

32
Q

What gas should be used during an evacuation to increase pressure to prevent freezing?

A

Dry nitrogen.

33
Q

What is the purpose of a compressor heater?

A

To reduce the amount of refrigerant in the i lubricating oil.

34
Q

How is moisture remaining from an evacuation removed from the refrigerant in a system?

A

By the filter-drier.

35
Q

What is the preferred method of leak checking a built-up system prior to charging?

A

Bubble solution.

36
Q

What would a technician initially look for during a visual inspection of a leaking hermetic system?

A

Stains around tubing and fittings.

37
Q

What is typically indicated by excessive superheat on a high-pressure system?

A

Undercharged system, possibly the result of a leaky system.

38
Q

Which refrigerant should be used for a trace charge during leak detection?

A

R-22.

39
Q

How do you leak check an HFC-134a system with a partial charge (no HFC-134a detector available)?

A

Recover remaining 134a, pressurize the system with nitrogen and a trace charge of R-22 so you
can use an HCFC electronic leak detector.

40
Q

Is the refrigerant leaving a receiver a liquid or a gas? Is it at a high or low pressure?

A

Liquid, high pressure.

41
Q

What is the initial charging method of a system when the charge is specified at 70 pounds?

A

Charged in liquid state.

42
Q

Is the receiver on the high or low side of a system?

A

High side.

43
Q

What is the minimum recommended capability (measured in microns) of a vacuum pump used for evacuations?

A

Should pull a vacuum of 500 microns,

44
Q

What is the pressure of a CFC-12 machine at 72 deg. F while the machine is idle?

A

73 PSIG.

45
Q

What is the preferred unit of measurement for checking a deep vacuum?

A

Microns.

46
Q

Where is an accumulator located in a refrigeration system?

A

On the suction line before the compressor.

47
Q

To prevent freezing of any moisture in a CFC-12 system, vapor should first be charged until the pressure is at what level?

A

33 PSIG

48
Q

For what purpose are soap bubbles used in leak checking?

A

For a visual check for leaks.

49
Q

Shaft seals on an open type compressor are susceptible to what failures?

A

Refrigerant leaks.

50
Q

What leak rate is permissible on industrial and process refrigeration?

A

Effective 6/14/93, any leak rate of 35% or more on equipment with 50 lbs. of charge or more must be repaired. Less than 35% is permissible.

51
Q

What leak rate is permissible on equipment (other than industrial or process equipment) that contains more than 50 lbs. of refrigerant?

A

Less than 15% annually.

52
Q

What is the easiest way to check the type of refrigerant used in a packaged rooftop system?

A

By the equipment data plate.

53
Q

Refrigerant will recover fastest in which phase, liquid or vapor?

A

Liquid.

54
Q

Which refrigerant line should a recovery machine be attached to in order to recover liquid refrigerant from a system?

A

To the liquid line,

55
Q

After a liquid recovery, what must be done with the vapor still in the system?

A

must Vapor recovery bust be performed.

56
Q

Before using a recovery unit, the technician should check service valve positions and check the recovery unit oil level. What additional step must be taken?

A

All solenoid valves should be open

57
Q

What is the primary purpose for using hand valves and sell sealing hoses when using a gauge set?

A

To prevent loss of refrigerant when connecting or disconnecting hoses.

58
Q

What can cause recovery equipment with a hermetic compressor to overheat when drawing a deep vacuum?

A

No airflow over the compressor body or no suction gas flow over the internal motors, or a combination of the two.

59
Q

What is the reason for not operating a hermetic refrigeration compressor while it is in a deep vacuum?

A

To prevent overheating the compressor motor.

60
Q

What is the reason for not starting a reciprocating compressor with its discharge service valve closed?

A

To prevent overheating the compressor motor.

61
Q

When can a “system-dependent” recovery device be used?

A

On small appliances as long as the device meets EPA standards and the technician adheres to the servicing procedures specified for the recovery equipment. Cannot be used on systems with more
than 15 lbs. of refrigerant.

62
Q

What vacuum level must you reach when recovering from a system with 38 pounds of R-502 using a recovery machine manufactured in 1995?

A

10 inches of Hg.

Epa (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions