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Use Charging, Evacuation and Measuring Tools > Modern Chapter 52 - Quiz > Flashcards

Modern Chapter 52 - Quiz Flashcards

1
Q

Which of the following statements regarding codes and code enforcement is false?

a) failure to secure permits may result in the loss of a technicians license
b) municipalities are required to adopt all ASHRAE standards as part of their codes

A

b)

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2
Q

For expansion valves with flared connections, a rubber seal at the end of the flare nut is used to prevent ____.

ice formation

tubing bends

sensing bulb failure

None of the above.

A

ice formation

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3
Q

In multiple-evaporator systems, TXVs are installed along with individual ____ in the liquid line to each evaporator.

check valves

evaporator pressure regulators

condensate drains

solenoid valves

A

solenoid valves

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4
Q

When installing TXV sensing bulbs, ____.

avoid using mounting straps that conduct heat well

do not wrap the sensing bulb in foam tape

do not mount the sensing bulb on the very bottom of a tube

All of the above.

A

do not mount the sensing bulb on the very bottom of a tube

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5
Q

An evaporator pressure regulator should be connected between the ____ and the suction line manifold.

accumulator

evaporator outlet

metering device

liquid line manifold

A

evaporator outlet

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6
Q

Hard-drawn ACR tubing used in commercial refrigeration is usually Type ____.

K

M

O

R

A

K

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7
Q

Hard-drawn ACR tubing requires ____ joints.

welded

flared

soldered

brazed

A

brazed

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8
Q

A multiple-evaporator system may use a ____ to bring the various lines to a centralized point.

conduit clamp

vibration loop

check valve

manifold

A

manifold

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9
Q

The liquid line manifold distributes refrigerant from a single line to separate ____.

condensers

metering devices

suction line manifolds

compressors

A

metering devices

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10
Q

If a suitable vibration absorber is not available, an alternate method to reduce the spread of vibration involves making a(n) ____.

adjustment to the metering device

loop of soft copper tubing

spring mounting for nearby components

None of the above.

A

loop of soft copper tubing

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11
Q

Which of the following statements regarding filter-driers is false?

Filter-driers hold more moisture at higher temperatures.

Filter-driers help to protect the compressor from contamination.

Filter-drier size is partly based on compressor horsepower.

If specifications indicate that a system falls between two different filter-drier sizes, choose the larger filter-drier.

A

filter driers hold more moisture at higher temperatures

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12
Q

Circuits with ____ or more should be wired by a licensed electrician.

5 V

12 V

24 V

120 V

A

120v

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13
Q

When installing a direct-drive compressor motor, check the alignment with a ____ before tightening the bolts.

measuring tape

micrometer

multimeter

dial indicator

A

dial indicator

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14
Q

If a system’s recommended testing pressure is not listed, the pressure should not exceed ____.

17 psig (219 kPa)

50 psig (446 kPa)

75 psig (618 kPa)

170 psig (1270 kPa)

A

170psig

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15
Q

Before adding refrigerant to a system, a technician should ____.

evacuate the system to eliminate moisture

force cold air through the lines

charge the system to a high pressure using the proper refrigerant

open the refrigerant circuit to atmosphere

A

evacuate the system to eliminate moisture

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16
Q

The low-side charging method involves adding ____ to the low side of a system.

inert gas

zeotropic refrigerants

refrigerant vapor

None of the above.

A

refrigerant vapour

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17
Q

After a newly installed system has operated for ____ hours, test it for leaks again.

6

12

24

40

A

24 hours

18
Q

One method of starting a multiple-evaporator system requires the technician to manually throttle the ____.

evaporator pressure regulator

suction service valve

thermostatic expansion valve

discharge service valve

A

suction service valve

19
Q

The best way to keep oil and liquid refrigerant in the condenser and prevent them from migrating back into the compressor during the Off cycle is to install ____ in the compressor discharge line.

a flow switch

a pressure-regulating valve

a solenoid valve

traps

A

traps

20
Q

The vibration from a running compressor is commonly and safely absorbed by ____.

mounting grommets

nearby electrical wiring

tension belts

a pulley system

A

mounting grommets

21
Q

Most sight glasses are sized based on the diameter of the ____.

discharge line

hot-gas bypass line

liquid line

suction line

A

liquid line

22
Q

A field-erected system is also called a ____ system.

packaged

split

commercial

multiple-cabinet

A

split

23
Q

The installation of domestic systems is usually covered by a municipality’s codes.

True
False
A

false

24
Q

A compressor’s discharge line should be slanted toward the compressor and away from the condenser.

True
False
A

false

25
Q

A multiple-evaporator installation should always have an evaporator pressure regulator installed between the outlet of the coldest evaporator and the suction line.

True
False
A

false

26
Q

An accumulator mounted in the suction line near the compressor helps cut down on high-side pressure fluctuations.

True
False
A

false

27
Q

Hard-drawn ACR tubing is not very pliable, so the joints must be brazed.

True
False
A

true

28
Q

If possible, the installation of commercial refrigerant lines should be completed in one day.

True
False
A

true

29
Q

If galvanized electrical conduit clamps are used to support refrigerant lines, the tubing should be protected with wrappings of plastic tape or some other insulating material.

True
False
A

true

30
Q

When installing a commercial refrigeration system, a technician should mount the suction line with a slight slope toward the evaporator.

True
False
A

false

31
Q

A sight glass should be installed in the suction line with brazed connections.

True
False
A

false

32
Q

Flux chemicals can affect a moisture indicator’s color-changing element.
True
False

A

true

33
Q

HVACR technicians are permitted to connect and service electrical wiring within a unit.

True
False
A

true

34
Q

If a system’s high side and low side cannot be isolated and sealed from each other during testing, the low-side testing pressure should not be exceeded.
True
False

A

true

35
Q

If a leak cannot be found with an inert gas, a trace amount of refrigerant may be added to the refrigerant circuit so an electronic leak detector can be used.

True
False
A

true

36
Q

It takes less time to charge a system with vapor than it does with an equal weight of liquid refrigerant.

True
False
A

false

37
Q

When charging a system with liquid refrigerant using the high-side method, a technician should place the refrigerant cylinder upside-down on the charging scale.

True
False
A

true

38
Q

By throttling the suction service valve, a technician prevents the compressor from being overloaded during a hot pull down procedure.
True
False

A

true

39
Q

To speed up the low-side charging process, a technician can heat up the refrigerant cylinder using a torch.

True
False
A

false

40
Q

Commercial operations often change the layout of their refrigerated space without considering if the old system can satisfy the demand of the new layout.

True
False
A

true

41
Q

The location and position of a TXV sensing valve depends on the size of the condenser.
True
False

A

false

Use Charging, Evacuation and Measuring Tools (6 decks)

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