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Flashcards in EPA 410A Safety Deck (25)
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1

Polyolester (POE) oils stored in plastic containers will:

A) separate
B) become more alkaline
C) become acidic
D) absorb moisture through the plastic

D) absorb moisture through the plastic

2

R-407C has:

A) a foul odor
B) to be charged in the vapor phase
C) the ability to fractionate
D) no temperature glide

C) the ability to fractionate

3

A condensing unit designed for use with R22:

A) must be replaced with a model designed for use with R-410A
B) cannot withstand the higher pressure of R-410A
C) both A and B
D) none of the above

C) both A and B

4

In a refrigeration system, oil and refrigerant:

A) contain alkybenzene
B) mix with each other
C) do not touch each other
D) are not miscible

B) mix with each other

5

Removal of refrigerant from a system can be accomplished by these two basic methods:

A) condensation and evaporation
B) dew point and bubble point
C) superheating and subcooling
D) active and passive

D) active and passive

6

Ozone depletion is caused by:

A) HFCs
B) chlorine and bromine
C) R-410A refrigerants
D) all of the above

B) chlorine and bromine

7

The cylinder code for R-407C is:

A) medium brown (chocolate)
B) light green
C) rose
D) light blue

A) medium brown (chocolate

8

The receiver bypass:

A) prevents subcooled vapor from sitting in the receiver and losing its subcooling
B) prevents superheated liquid from sitting in the receiver and losing its superheat
C) prevents superheated vapor from sitting in the receiver and losing its superheat
D) prevents subcooled liquid from sitting in the receiver and losing its subcooling

D) prevents subcooled liquid from sitting in the receiver and losing its subcooling

9

For commercial and industrial refrigeration systems, a __________ annual leak rate is considered a substantial leak.

A) 25%
B) 15%
C) 5%
D) 35%

D) 35%

10

An overcharged system can cause:

A) frosted suction line
B) low compression ratio
C) high side pressure increase
D) high side pressure decrease

C) high side pressure increase

11

Polyolester lubricants (POEs) are used extensively with:

A) HFCs
B) lawn mowers
C) HCFCs
D) CFCs

A) HFCs

12

Technicians handling liquid refrigerant should wear gloves and:

A) steel-toe boots
B) self contained breathing apparatus (SCBA)
C) hearing protection
D) approved eye protection

D) approved eye protection

13

R-407C pressures and temperatures are similar to:

A) R-22
B) R-12
C) R-502
D) R-134a

A) R-22

14

Whenever possible, to avoid fractionation, charging of a refrigeration system incorporating a near-azeotropic blend should be done with:

A) liquid refrigerant
B) a scroll compressor
C) R-22
D) a yellow and gray recovery cylinder

A) liquid refrigerant

15

Liquid lines used with R-22:

A) may only be used with R410A in dry climates
B) may never be used with R-410A
C) may be used with R-410A if sized and properly cleaned
D) may be used with R-410A without additional considerations

C) may be used with R-410A if sized and properly cleaned

16

If R-410A is ingested:

A) immediately inject trioxide compound
B) drink milk
C) do not induce vomiting
D) induce vomiting

C) do not induce vomiting

17

Which refrigerant has an ozone depletion potential of zero?

A) R-22
B) HCFC-22
C) CFC-11
D) R-134A

D) R-134A

18

An advantage of ester-based oils such as Polyolester is:

A) they have a wax-free composition
B) they have low miscibility with R-410
C) they are very hygroscopic
D) they trap moisture

A) they have a wax-free composition

19

Polyalkylene Glycol (PAG) oils:

A) are non-toxic if inhaled
B) are extremely hygroscopic
C) perform well in aluminum-on-steel applications
D) all of the above

B) are extremely hygroscopic

20

Charging a R-410A system until the sight glass is clear may result in:

A) compressor damage
B) system overcharge
C) proper charge
D) both A and B

D) both A and B

21

The temperature of a single compound at 100% saturated vapor with no superheat is:

A) greater than its saturation temperature for that pressure
B) equal to its saturation temperature for that pressure
C) less than its saturation temperature for that pressure
D) none of the above

B) equal to its saturation temperature for that pressure

22

R-410A systems may be topped off after a leak because:

A) it has a very high temperature glide
B) its cylinder is rose
C) it must be weighed in
D) it behaves like a pure compound

D) it behaves like a pure compound

23

To find the correct saturation temperature for a given pressure, its best to use:

A) the dew point
B) the compression ratio formula
C) a gauge manifold
D) a pressure/temperature chart

D) a pressure/temperature chart

24

Temperature glide can range from:

A) 0.2 deg to 16 deg F
B) -3 deg to 8 deg F
C) 5 deg to 16 deg F
D) 5.6 deg to 20 deg F

A) 0.2 deg to 16 deg F

25

A liquid changes to a vapor by absorbing:

A) sensible heat
B) superheat
C) moisture
D) latent heat

D) latent heat