Modern Chapter 52 - Quiz

Question 1

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

Answer 1

b)

Question 2

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.

Answer 2

ice formation

Question 3

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

Answer 3

solenoid valves

Question 4

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.

Answer 4

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

Question 5

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

accumulator

evaporator outlet

metering device

liquid line manifold

Answer 5

evaporator outlet

Question 6

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

K

M

O

R

Answer 6

K

Question 7

Hard-drawn ACR tubing requires ____ joints.

welded

flared

soldered

brazed

Answer 7

brazed

Question 8

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

conduit clamp

vibration loop

check valve

manifold

Answer 8

manifold

Question 9

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

condensers

metering devices

suction line manifolds

compressors

Answer 9

metering devices

Question 10

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.

Answer 10

loop of soft copper tubing

Question 11

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.

Answer 11

filter driers hold more moisture at higher temperatures

Question 12

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

5 V

12 V

24 V

120 V

Answer 12

120v

Question 13

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

measuring tape

micrometer

multimeter

dial indicator

Answer 13

dial indicator

Question 14

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)

Answer 14

170psig

Question 15

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

Answer 15

evacuate the system to eliminate moisture

Question 16

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

inert gas

zeotropic refrigerants

refrigerant vapor

None of the above.

Answer 16

refrigerant vapour

Question 17

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

6

12

24

40

Answer 17

24 hours

Question 18

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

Answer 18

suction service valve

Question 19

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

Answer 19

traps

Question 20

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

mounting grommets

nearby electrical wiring

tension belts

a pulley system

Answer 20

mounting grommets

Question 21

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

discharge line

hot-gas bypass line

liquid line

suction line

Answer 21

liquid line

Question 22

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

packaged

split

commercial

multiple-cabinet

Answer 22

split

Question 23

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

True
False

Answer 23

false

Question 24

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

True
False

Answer 24

false

Question 25

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

Answer 25

false

Question 26

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

Answer 26

false

Question 27

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

Answer 27

true

Question 28

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

Answer 28

true

Question 29

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

Answer 29

true

Question 30

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

Answer 30

false

Question 31

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

Answer 31

false

Question 32

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

Answer 32

true

Question 33

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

Answer 33

true

Question 34

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

Answer 34

true

Question 35

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

Answer 35

true

Question 36

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

Answer 36

false

Question 37

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

Answer 37

true

Question 38

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

Answer 38

true

Question 39

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

Answer 39

false

Question 40

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

Answer 40

true

Question 41

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

Answer 41

false