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Term 3 - Review Tests > Pre-Test #1 > Flashcards

Pre-Test #1 Flashcards

1
Q

On an electric TXV valve, what would happen if a wire from the sensor broke?

a) valve goes open
b) valve goes closed
c) valve goes 1/4 open

A

b) fully closed

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2
Q

What minimum height must a refrigerant pipe be that crosses an area that affords a passageway?

a) 9 feet
b) 6 feet
c) 8.5 feet
d) 7.5 feet

A

d)

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3
Q

When installing a display freezer, how would you level the unit?

A

to the highest point

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4
Q

A fan in a display case is used for what purpose?

a) assist in condenser air circulation
b) assist in maintaining air patterns
c) keep flies away

A

b)

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5
Q

What type of sensing element would be used on a temperature sensor for a return air duct?

a) close coupled bulb
b) bulb and capillary
c) averaging
d) mercury thermostat

A

c)

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6
Q

The formation of sweat around the door on a display case is limited by

a) keeping dew point below box temp
b) circulate cold air
c) electric heaters - mullion heaters

A

c)

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7
Q

Fan coil units used in medium temperature cases are usually defrosted with

a) electric
b) hot gas
c) hand scraping
d) unit off cycle

A

d)

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8
Q

When selecting a replacement gear style oil pump, for a non-rotational specific, compressor the most important factor is

a) rotation
b) gasket
c) pumping volume
d) shaft speed

A

c)

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9
Q

If an oil pressure control should open due to lack of oil pressure, the voltage reading across the L and M terminals would read, if the supplied control voltage were 240v

a) 240v
b) 120v
c) 0v
d) 24v

A

a)

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10
Q

Which of the following refrigerants would you charge as a liquid?

a) 507
b) 134a
c) 22
d) 401

A

d)

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11
Q

To replace a condenser on a system with a receiver and only compressor service valves, you must;

a) close the king valve and discharge valve, pump down and make repair
b) close king and suction, pump down and make repair
c) front seat discharge and suction, pump down and make repair
d) pump out system and make repair

A

d)

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12
Q

On an ammonia system for recreational centre the refrigeration lines maybe painted

a) suction light green, discharge red
b) suction red, discharge light green
c) suction yellow, discharge light blue

A

a)

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13
Q

Once the plastic pipe for secondary refrigerant has been laid and before they are back filled they must be;

a) stretched
b) shrunk
c) pressure tested
d) painted

A

a)

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14
Q

What do you put on top of sleepers in an arena?

a) pipe chairs
b) floor coolant piping
c) side boards
d) sleeping spectators

A

a)

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15
Q

Spacing between sleepers or chairs in an arena floor is a usual minimum

a) 3 feet
b) 2 yards
c) 10ft
d) 6 inches

A

a)

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16
Q

How would you isolate the metering device;

a) front seat discharge and pump down
b) front seat suction and pump down
c) back seat suction and pump down
d) remove refrigerant

A

d)

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17
Q

To change an evaporator in a multiple system that has a king valve at the receiver and solenoids

a) disconnect power from solenoid, pump down and replace
b) front seat, close, the king valve, power all solenoids and pump down the system then close the suction service valve, disconnect and lock out power

A

b)

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18
Q

The sleepers installed in a rink floor are used to

a) support headers
b) support insulation
c) support concrete
d) supports chairs for Refrigeration piping

A

d)

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19
Q

The polyvinalchloride refrigeration piping for a rink floor is connected to the header by

a) single clamp
b) 2 clamps
c) a brazed fitting
d) 2 clamps and a nipple

A

d)

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20
Q

A 240v single phase electrostatic air cleaner requires

a) 2 pole disconnect on supply
b) single pole breaker
c) no protection
d) a control fuse set at 26.5 amps

A

a)

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21
Q

An electronic air cleaner supplied with 120v

a) requires roll filters
b) requires spst disconnect at unit
c) only operates when y terminal is energized
d) requires special 2 pole ground fault protection

A

d)

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22
Q

A reverse acting controller which receives an increasing signal from the sensor

a) cause output to increase proportionally
b) decrease output
c) remain at null

A

b)

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23
Q

To change rotation of a PSC motor with two leads

a) stator rotated 180 degrees
b) end bells switched to opposite ends of stator
c) run winding leads reversed

A

b)

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24
Q

A pilot valve on a gas fired appliance

a) pulled in by voltage supplied by thermocouple
b) held in by voltage supplied by thermocouple
c) only used on power pile operation

A

b)

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25
Q

A pressure relief valve is leaking on the condenser

a) shut down system and replace
b) thread pipe plug on discharge
c) answer b would work the plug was fusible

A

a)

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26
Q

A shorted start capacitor on a capacitor start motor

a) motor will start normally
b) motor will not start
c) motor hums, may try to start but cuts on overload

A

c)

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27
Q

A PSC motor has an open run capacitor

a) motor will operate normal because the cap is only installed to replace current lag
b) motor would hum, not start, and trip overload

A

b)

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28
Q

A device which closes as the downstream pressure of the refrigerant rises?

a) EPR
b) CPR
c) Head master
d) CNR

A

b)

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29
Q

Pressure on the inlet side of a regulator is controlled in

a) CNR
b) BNP
c) CPR
d) EPR

A

d)

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30
Q

In an air to air heat pump in heating mode, with check valves in the bypass circuit

a) check valve is open at outdoor coil
b) check valve is open on crankcase bypass circuit, to prevent frosting
c) check valve os open at the inside coil metering device

A

c)

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31
Q

How would you check to see if a remote heater was operating

a) voltage across circuit
b) amperage of the heater
c) resistance

A

b)

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32
Q

Symptom of a frozen freezer vent , and the walk in being in a vacuum

a) compressor draw higher amps
b) defrost cycle increases
c) flooding
d) door will be hard to open

A

d

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33
Q

What protects a pneumatic system against a high pressure
a) compressor
b) air dryer
c) pressure regulator
d)pressure relief valve

A

d)

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34
Q

While doing an inspection on a. fan bearing it is discovered that the bearing is spinning in the housing

a) replace bearing
b) pean over the edges of bearing housing to better support
c) replace housing and bearing
d) replace motor

A

c)

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35
Q

In an evaporative condenser that is cycling the cooling mediums

a) fans are first on, as pressure rises and the water is last off as pressure falls
b) fans are first, as pressure rises, and last off as pressure falls

A

a)

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36
Q

Min height of refrigerant piping crossing a passageway is?

A

7.5ft

37
Q

On a roof top unit the heat call is met, but the blower keeps running, even though the heat exchanger is cool, the cause is

a) high limit switch welded shut
b) control transformer operating the fan control relay is shorted
c) fan cycling control is welded shut

A

c

38
Q

As suction pressure increases, the net oil pressure would

a) rise by the same amount of suction
b) stay relatively the same
c) fall due to difference in compression ratio

A

b)

39
Q

As the suction pressure increases the GROSS oil pressure will

a) rise by approx same pressure of suction presure
b) stay the same
c) fall due to difference in compression ration

A

a

40
Q

A hanger supported by 2 rods from 2 separate roof support members is?

a) pivot type hanger
b) point to point hanger
c) trapeze hanger
d) a point clevis hanger

A

c)

41
Q

If the entering air temperature stays constant, and the relative humidity of the entering air is lowered, the dry bulb temperature difference across the evaporator coil will

a) stay the same
b) decrease
c) increase
d) vary

A

c)

42
Q

An AC with no receiver and a restricted drier on the txv could show

a) d)
b) low suction, high amps, high discharge, low subcool
c) low suction, normal amps, slightly high discharge and high subcool

A

a)

43
Q

An AC with a receiver and a restricted drier on the txv could show

a) low suction, low amps, normal to high discharge and subcooling
b) low suction high amps high discharge low subcool
c) low suction normal amps slight high discharge and low subcool
d) low suction, low amps, low discharge, high sub cooling

A

d)

44
Q

An AC system that has a restricted flow through the filter drier will show

a) flashing in sight glass at receiver
b) cooler temperature after the drier
c) cooler than normal compressor

A

b)

45
Q

On a TXV with floating head, at low ambient outside temp the valve may not pass enough refrigerant to keep coil active due to

a) high pressure drop
b) low compression hp
c) low sub cooling in condenser
d) pressure differential across tx

A

d) its too low due to ambient

46
Q

***Higher than design condensing temperatures will cause loss of capacity due to

a) lower NRE caused by higher amounts of flash gas in txv (due to high pressure of expansion gas)
b) higher volumetric efficiency
c) lower sub cooling

A

a)

47
Q

Low compressor amperage caused by

a) high superheat
b) low superheat
c) high SCT
d) high sub cooling

A

a) lower refrigerant flow thus low amps

48
Q

A PSC motor is stuck, you could free the rotor by

a) substitute larger run capacitor
b) increase breakdown voltage of cap
c) install start cap and relay in parallel with run winding
d) install start cap and relay in parallel with run cap

A

d)

49
Q

Before the slab for a think surface is poured, the secondary refrigerant piping is

a) x rayed for cracks
b) pressure tested
c) re-glued
d) stretched

A

d)

50
Q

Difference across an inlet and outlet of an evaporator for an air conditioning system circuit is?

a) 10 to 15 SC
b) 6 to 8 SH
c) 6 to 8 SC
d) 10 to 15 SH

A

d)

51
Q

The length of the liquid line will usually

a) increase superheat absorbed by the refrigerant
b) increase sub cooling due to temperature difference between ambient air and the refrigerant leaving the condenser or receiver
c) will cause further cooling in refrigerant

A

b)

52
Q

Sequencing relays in an electric furnace are used for

a) limiting inrush current from the supply
b) limit the overshoot of supply air temperature to the space
c) staging blower speeds

A

a)M

53
Q

Minimum reading when testing a thermocouple

a) 17mv no load
b) 30mv loaded
c) 10mv loaded
d) 30 mv no load

A

d)

54
Q

A technician while pressure washing flattens the condenser fins

a) head rise, suction/sh fall,
b) head rise, SC rise, reduction in capacity, higher suction,

A

b)

55
Q

How is a lockout relay connected in a control circuit?

a) coil in parallel with safety devices, contacts in series with comp cont coil
b) coil in parallel with safety devices, contacts in series with safety devices

A

b)

56
Q

What should be used between the back of a flare and the nut?

a) nothing
b) lubricant
c) gasket
d) pipe sealing compound

A

b)

57
Q

When making 90 bends in tubing where is the measurement between bends taken from?

a) centre of the bend
b) back of bend
c) end of bend

A

a)

58
Q

In a system using a blended refrigerant, what data is required to calculate the condenser sub cooling?

a) condenser inlet pressure and temperature and bubble point
b) condenser inlet pressure and temperature and dew point
c) condenser outlet pressure and temperature and bubble point
d) condenser outlet pressure and temperature and dew point

A

c)

59
Q

During evacuation, when should the gas ballast on a vacuum pump be closed?

a) only be open during venting of pressure from system
b) closed as soon as vacuum starts to pull
c) has no effect on operation
d) closed near the end of the vacuum process

A

d)

60
Q

If the shaft seal was leaking on an open driven semi-hermetic compressor, you would

a) re-lubricate the mating surfaces
b) remove the seal, re-lap, checking with feeler gauge
c) replace the seal
d) adjust spring

A

c)

61
Q

Net oil pressure is

a) inlet temp minus outlet
b) suction pressure minus inlet temp
c) discharge pressure minus suction pressure
d) gross oil pressure minus suction pressure

A

d)

62
Q

How do you secure pipes to a steel beam?

a) beam clamp
b) riser clamp
c) inverted clevis clamp

A

a)

63
Q

What would you install in the piping between 2 chilled water coils

a) drip leg
b) union
c) bucket trap

A

b)

64
Q

Where is the king valve located?

A

outlet of receiver

65
Q

The purpose of the king valve is

a) isolate the condenser
b) isolate the metering device
c) allow pressure readings of the receiver vapour
d) allow service pump down

A

d)

66
Q

When performing a repair it is found the oil is contaminated, what shall be done

a) replace drier, evacuate, recharge
b) remove oil, install new oil, evacuate, charge
c) remove oil, store in approved cylinder, new drier, refill, evacuate, recharge, recover

A

C)

67
Q

How would an existing system be isolated to install a new TXV

a) front seat liquid line service valve, pump down, front seat suction
b) front seat queen valve and suction
c) back seat liquid line valve and suction valve to pump down

A

a)

68
Q

In low ambient condition on a cap tube system

a) head high suction low
b) head low suction unchanged
c) head low suction low
d) head maintained

A

c)

69
Q

While purging the refrigeration piping, if pressure is too high

a) filler material will not flow
b) pin holes may develop
c) pipe will oxidize rapidly

A

b)

70
Q

What must be installed between the main supply line and coil in a hydronic heating system?

a) flexible braided hose
b) swing joint
c) series of clamps
d) union

A

d)

71
Q

Barometric damper is used for

a) causes a near constant air pressure through combustion chamber
b) causes stack pressure to remain constant
c) causes stack flue gases to remain constant temp

A

a)

72
Q

A barometric damper is located

a) between heat exchanger outlet and primary control
b) between primary control and the chimney
c) between draft hood and chimney

A

b)

73
Q

Transport system that will keep frozen foods at temp that has no mechanical refrigeration system

a) eutectic plate system,
b) dx system
c) centrifugal system

A

a)

74
Q

A technical transport refrigeration system can be

a) operated by a vehicle engine driven compressor
b) an electric compressor
c) diesel or gas engine driven compressor
d) all of the above

A

d)

75
Q

Eutectic plates can be re-frozen by

a) circulating refrigerant through coil built in plate
b) circulate brine solution with lower eutectic point solution through coil inside plate
c) removing energy from the place that the brine solution has collected through the day
d) all of the above

A

d)

76
Q

A transport system that uses liquid nitrogen

a) uses compressor to move the refrigerant
b) require no venting
c) cools load by using heat energy from the load to change state of refrigerant

A

c)

77
Q

An eutectic solution is

a) blend of 2 solutions providing low melting temp
b) refrigerant
c) solution using sodium chloride or calcium chloride and water
d) all of the above

A

d)

78
Q

When retrofitting a system from CFC 12 to HFC 134

a) tx requires changing
b) accumulator changed
c) liquid drier
c) all

A

c)

79
Q

An instrument used to check alignment of two shafts connected with a coupling

a) vernier caliper
b) inside caliper
c) hermaphrodite caliper
d) dial indicator

A

d)

80
Q

Vapour barrier on a walk in cooler, placed on the inside of the building is

a) not required
b) between insulation and interior of box
c) both sides of insulation
d) placed on warm side of insulation

A

d)

81
Q

A weak spring on a txv will cause

a) superheat to increase
b) superheat to remain constant
c) sub cooling of the refrigerant
d) loss of superheat and possible hunting

A

d)

82
Q

If compressor ran continuously, what would you visually check

a) high pressure cut out, see if tripped
b) motor starter to see position of armature
c) oil failure
d) hand positon

A

b)

83
Q

An AC with latching fault indicators

a) lose faults if thermostat cycled
b) loose fault if thermostat batteries die
c) will loose fault if unit power is cycled

A

c)

84
Q

To decommission a refrigeration system you would

a) leave system will full charge of freon
b) leave system with low charge of freon
c) leave system with high charge nitro
d) leave low charge nitrogen

A

d)

85
Q

Replacing an evaporator in a multiple evaporator system

a) manually open solenoid valves, pump down, lock off power
b) manually open valves, close liquid line, pump down, close suction, LOTO

A

b)

86
Q

On a RTU with a cap tube and low ambient temperature the result

a) high SC low SH
b) low SC high SH
c) high TD

A

b)

87
Q

To wet the sock on a sling psychrometer use

a) distilled 10f above ambient water
b) distilled water at ambient

A

b)

88
Q

Authority for refrigeration container certification?

a) ASHRAE
b) DOT
c) ASME
d) HRAI

A

b)

89
Q

An RTU is short cycling on heating

a) heat anticipator too low
b) gas pressure too low
c) plugged evaporator
d) fan RPM too high

A

c)

Term 3 - Review Tests (2 decks)

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