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Refrigerant Machine Operator Practical > Refrigerant Machine Operator Practice Test #3 > Flashcards

Refrigerant Machine Operator Practice Test #3 Flashcards

1
Q

AS AN RMO YOU ENTER A SYSTEM OF A RECIPROCATING REFRIGERATION UNIT. THIS SYSTEM HAS A 150 LB. REFRIGERANT CHARGE, YOU WOULD EXPECT TO FIND STOP VALVES:

ON THE INLET SUPPLY AND DISCHARGE LINE

BEFORE AND AFTER LIQUID BULL’S EYE SIGHT GLASS

ON THE INLET LINE OF THE CONDENSER RECEIVER

ON THE INLET TO EACH COMPRESSOR

A

ON THE INLET LINE OF THE CONDENSER RECEIVER

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2
Q

HOW DO YOU INCREASE THE PRESSURE OF A CENTRIFUGAL COMPRESSOR?

VARIABLE GUIDE VANES

INCREASE SUB COOL LEVEL

INCREASE SPEED OF MOTOR

ALL OF THE ABOVE

A

INCREASE SPEED OF MOTOR

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3
Q

THE STRENGTH OF THE STRONG LIQUOR IN AN ABSORPTION SYSTEM DECREASES AS THE:

EXPANSION VALVE IS OPENED

CONDENSER PRESSURE DECREASES

EVAPORATOR LOAD INCREASES

EVAPORATOR LOAD DECREASES

A

EVAPORATOR LOAD DECREASES

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4
Q

WHAT IS A STEAM JET ON A SURFACE CONDENSER USED FOR?

TO CREATE HIGH PRESSURE TO MAINTAIN HIGH STEAM VELOCITY

TO MAINTAIN STEAM LEVEL INSIDE CONDENSER

TO CREATE PROPER EXHAUST VACUUM

ALL OF THE ABOVE

A

TO CREATE PROPER EXHAUST VACUUM

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5
Q

AXVs MAINTAIN CONSTANT EVAPORATOR PRESSURE, THEY ALSO:

CLOSE WHEN THE LOAD INCREASES

ARE USED WHEN THERE IS A WIDE RANGE IN LOAD

ARE AFFECTED BY CONDENSER HEAD PRESSURE

REQUIRE OTHER SAFETY DEVICES WHEN BEING USED IN EVAPORATORS THAT CHILL WATER

A

CLOSE WHEN THE LOAD INCREASES

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6
Q

IF THE UNLOADER FAILS TO OPERATE WHEN NEEDED, WHAT WOULD HAPPEN?

EVAPORATOR PRESSURE WILL REMAIN UNAFFECTED

EVAPORATOR TEMPERATURE WILL GO DOWN

COMPRESSOR WILL SHORT CYCLE

COMPRESSOR WOULD VIBRATE

A

EVAPORATOR TEMPERATURE WILL GO DOWN

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7
Q

A CENTRIFUGAL PUMP OPERATES AT 92 FEET HEAD. WHAT WOULD BE THE CORRESPONDING PRESSURE IN PSIG BE CLOSEST TO?

180

20

40

90

A

40

2.31 feet of head to psi

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8
Q

THE ELECTRIC POWER DELIVERED TO A LIQUID LINE SOLENOID VALVE IS MEASURE IN:

OHMS

VOLTAGE

AMPS

WATTS

A

WATTS

Watts is the unit of power, or rate which energy is transferred or consumed

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9
Q

ON THE HIGH SIDE OF THE SYSTEM, LIQUID STOP VALVES SHOULD BE PLACED:

IN FRONT AND AFTER THE BULL’S EYE SIGHT GLASS

ON THE SUCTION LINE AND DISCHARGE LINE AFTER THE COMPRESSOR

IN FRONT OF AND AFTER THE MUFFLER

ALL OF THE ABOVE

A

IN FRONT AND AFTER THE BULL’S EYE SIGHT GLASS

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10
Q

A WATER REGULATING VALVE IS CONNECTED TO THE OUTLET OF THE CONDENSER. WHAT IS THIS VALVE DESIGNED TO DO?

MAINTAIN A CONDENSER PRESSURE WITHIN PRESET LIMITS

MAINTAIN A CONSTANT WATER PRESSURE

MAINTAIN A CONSTANT WATER TEMPERATURE

MAINTAIN A CONSTANT CONDENSER PRESSURE

A

MAINTAIN A CONSTANT CONDENSER PRESSURE

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11
Q

THE AUTOMATIC EXPANSION VALVE (AEV) IS USED INSTEAD OF A TEV. IT MAINTAINS A CONSTANT PRESSURE ON THE EVAPORATOR. ANOTHER FUNCTION IT MAY HAVE IS:

WORKS WELL ON VARIABLE LOADS

ALLOWS REFRIGERANT ON RISE IN PRESSURE

NEEDS TEMPERATURE CONTROL TO PROTECT EVAPORATOR FROM FREEZING UP FROM COLD WATER

ON WATER TYPE EVAPORATOR, FREEZING WILL NOT OCCUR

A

ON WATER TYPE EVAPORATOR, FREEZING WILL NOT OCCUR

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12
Q

WHEN READING THE HP OF A THREE PHASE MOTOR USING A CLAMP ON AMMETER YOU WOULD:

TAKE MEASUREMENT ON ALL 3 PHASES

TAKE MEASUREMENT ON ONE PHASE ONLY

AMMETER ONLY READS AMPS

TAKE VOLTAGE MEASUREMENT

A

AMMETER ONLY READS AMPS

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13
Q

IN AN AMMONIA ABSORPTION SYSTEM THE ANALYZER IS LOCATED BETWEEN THE:

GENERATOR AND RECTIFIER

ABSORBER AND EVAPORATOR

RECTIFIER AND CONDENSER

CONDENSER AND RECEIVER

A

GENERATOR AND RECTIFIER

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14
Q

THE PRESSURE OF WATER GOING THROUGH A SHELL AND TUBE CONDENSER IS PROPORTIONAL TO THE SQUARE OF ITS VELOCITY. IF ITS VELOCITY ORIGINALLY WAS 40 AND IT’S ORIGINAL PRESSURE WAS HALVED, WHAT WOULD THE VELOCITY BE?

40

30

20

10

A

10

The pressure of water going through a shell and tube condenser is proportional to the square of its velocity. If the original velocity was 40 and the original pressure was halved, the new velocity can be calculated by taking the square root of the original velocity and multiplying it by the square root of the original pressure. In this case, the square root of 40 is 6.32, and the square root of 0.5 (halved pressure) is 0.71. Multiplying these two values together gives a new velocity of approximately 4.49, which is closest to 10. Therefore, the new velocity would be 10.

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15
Q

A SAFETY HEAD IS:

PRESSURE RELIEF VALVE INSIDE THE COMPRESSOR

PRESSURE RELIEF VALVE AT TOP OF THE HEAD

VALVE PLATE BEING HELD DOWN BY A SPRING

HIGH SIDE PRESSURE IN SYSTEM BELOW DESIGN PRESSURE

A

VALVE PLATE BEING HELD DOWN BY A SPRING

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16
Q

THE TYPE OF REFRIGERANT IN THE FEELER BULB ON A SYSTEM WOULD BE:

SAME AS REFRIGERANT IN SYSTEM

HIGHLY FLAMMABLE / HIGHLY TOXIC

NON FLAMMABLE / NON TOXIC

WOULD BE DIFFERENT TYPE OF REFRIGERANT THAN THE ONE IN THE SYSTEM

A

NON FLAMMABLE / NON TOXIC

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17
Q

WHAT IS A MAJOR ADVANTAGE OF HAVING A TWO STAGE CENTRIFUGAL COMPRESSOR WITH IMPELLERS BACK TO BACK?

LOWER THRUST LOAD ON BEARINGS

ONE OF THE IMPELLERS CAN BE STOPPED TO ADJUST TO THE LOAD CONDITIONS

YOU CAN USE DIFFERENT EVAPORATORS TO FEED DIFFERENT REFRIGERANTS TO EACH

THEY CAN BE OPERATED AT A LOWER SPEED THAN THE SINGLE STAGE

A

THEY CAN BE OPERATED AT A LOWER SPEED THAN THE SINGLE STAGE

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18
Q

A MOTOR PULLEY HAS A DIAMETER OF 3” AND RUNS AT 1,400 RPMs. THE FAN PULLEY HAS A DIAMETER OF 5¼”, AT HOW MANY REVOLUTIONS PER MINUTE DOES THE FAN PULLEY REVOLVE?

800 RPMs

1600 RPMs

200 RPMs

1800 RPMs

A

800 RPMs

The speed of rotation of a pulley is inversely proportional to its diameter. In this case, the motor pulley has a smaller diameter than the fan pulley, so it will rotate faster. The ratio of the diameters is 3/5.25 (3 divided by 5.25), which is approximately 0.571. Since the motor pulley rotates at 1,400 RPMs, the fan pulley will rotate at 0.571 times that speed, which is approximately 800 RPMs.

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19
Q

HOW DO YOU KEEP PROPER WATER LEVEL IN THE HOT WELL?

SLOW TURBINE DOWN

ALTERNATE SPEED OF TURBINE

VERY FLOW OF CONDENSER WATER

WITH OVERBOARD AND RECYCLING VALVE

A

WITH OVERBOARD AND RECYCLING VALVE

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20
Q

TO PREVENT AGAINST STRUCTURAL COLLAPSE IN PIPE WORK, WHEN INSTALLING BENDED COPPER TUBING:

USE ANNEALED COPPER

USE A SPRING BENDER

USE A LARGE RADIUS

USE BRAZED ELBOWS

A

USE A LARGE RADIUS

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21
Q

FOR SYSTEMS CONTAINING 50 LBS OF REFRIGERANT, STOP VALVES ARE REQUIRED:

AT INLET OF EACH COMPRESSOR

AT INLET OF LIQUID RECEIVER

BEFORE AND AFTER SIGHT GLASS

NOT REQUIRED

A

AT INLET OF EACH COMPRESSOR

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22
Q

THE SUCTION SERVICE VALVE ON A RECIPROCATING MACHINE IS FRONT SEATED. YOU HAVE EVACUATED DOWN TO 25” Hg. YOU SHUT VACUUM PUMP OFF AND LOW SIDE PRESSURE RISES IMMEDIATELY. WHAT IS THE CAUSE?

FAULTY SUCTION SERVICE VALVE

FAULTY (SUCTION) COMPRESSOR VALVE

FAULTY DISCHARGE VALVE

FAULTY LIQUID LINE STOP VALVE

A

FAULTY (SUCTION) COMPRESSOR VALVE

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23
Q

WHAT IS THE MINIMUM HEIGHT LEVEL INSIDE THE MACHINERY ROOM EXHAUST?

LESS THAN 5’

MORE THAN 5’

25’

50’

A

LESS THAN 5’

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24
Q

AN ELECTRICAL WIRING SCHEMATIC WOULD SHOW:

THE PATH OF ELECTRICITY IN THE CIRCUIT

THE DIAGRAM OF A SWITCH

A POINT TO POINT PICTURE OF ALL THE WIRING IN THE CIRCUIT

ONLY DC WIRING

A

THE PATH OF ELECTRICITY IN THE CIRCUIT

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25
Q

HOW IS A WATTMETER USED?

BY USING 4 LEADS, AND TAKING 1 READING

BY TAKING 3 READINGS

BY USING OHMMETER

ALL OF THE ABOVE

A

BY USING 4 LEADS, AND TAKING 1 READING

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26
Q

IN ADDITION TO EVAPORATOR PRESSURE, WHAT OTHER FORCE DETERMINES THE FLOW THROUGH AN AUTOMATIC EXPANSION VALVE?

SPRING PRESSURE

CONDENSER PRESSURE

CUT-IN PRESSURE

DESIGN PRESSURE

A

SPRING PRESSURE

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27
Q

AN OPERATOR HAS BEEN ASSIGNED TO RUN A CENTRIFUGAL COMPRESSOR. THE CAPACITY CONTROL IS MOST LIKELY ACHIEVED BY:

INCREASING SPEED OF IMPELLER

ADJUSTING THE SIZE OF THE VANE PASSAGES

DECREASING THE SPEED OF THE IMPELLER

SOLENOID UNLOADERS

A

ADJUSTING THE SIZE OF THE VANE PASSAGES

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28
Q

THE OVERSPEED TRIP IS:

A DEVICE THAT WILL SLOW THE MACHINE DOWN IN THE EVENT OF EXCESSIVE SPEED

A GIMPLE SAFETY VALVE TO STOP THE TURBINE IN THE EVENT OF THE RPMs REACHING OVER THE MAXIMUM SPEED

A DEVICE TO DE-ENERGIZE MOTOR STARTER TO SHUT MOTOR DOWN IN THE EVENT OF RPMs REACHING OVER THE MAXIMUM SPEED

MECHANISM TO SIGNAL MACHINE TO INCREASE SPEED

A

A GIMPLE SAFETY VALVE TO STOP THE TURBINE IN THE EVENT OF THE RPMs REACHING OVER THE MAXIMUM SPEED

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29
Q

AFTER THE COMPRESSOR YOU HAVE THE OIL SEPARATOR, WHICH:

IN GENERAL RETURNS THE OIL TO THE CRANKCASE

FILTERS THE OIL AND RETURNS THE OIL TO THE CRANKCASE

REMOVES THE WATER FROM THE OIL

DISTRIBUTES OIL TO THE EVAPORATOR

A

IN GENERAL RETURNS THE OIL TO THE CRANKCASE

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30
Q

WHAT CONTROLS A SOLENOID VALVE ON MOTOR?

WATTS

VOLTS

HORSE POWER

AMPS

A

VOLTS

Volts control a solenoid valve on a motor. Solenoid valves are electromechanical devices that use an electrical current to control the flow of fluid or gas. The voltage applied to the solenoid coil determines the strength of the magnetic field generated, which in turn controls the opening and closing of the valve.

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31
Q

VENTILATION IN THE MACHINE ROOM DEPENDS ON THE:

AMOUNT OF FLAMMABLE REFRIGERANT

AMOUNT OF REFRIGERANT STORED IN THE CONTAINER

AMOUNT OF REFRIGERANT IN THE MACHINE

THE TOTAL AMOUNT OF REFRIGERANT IN THE MACHINERY ROOM

A

AMOUNT OF REFRIGERANT IN THE MACHINE

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32
Q

HOW DOES A RECIPROCATING COMPRESSOR VARY CAPACITY?

CYLINDER UNLOADERS

HOT GAS BYPASS

MOTOR SPEED VARIATIONS

ALL OF THE ABOVE

A

ALL OF THE ABOVE

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33
Q

HOW DO YOU CONTROL CAPACITY OF A CENTRIFUGAL COMPRESSOR WITH VARIABLE GUIDE VANES?

INCREASE SUB-COOLING

INCREASE THE SPEED OF THE MOTOR

VARY THE PASSAGES OF THE VANES

PISTON VALVE CLEARANCE

A

VARY THE PASSAGES OF THE VANES

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34
Q

What is the primary function of the receiver in a refrigeration system?

To absorb heat from the refrigerant

To store the refrigerant after condensation

To increase the pressure of the refrigerant

To maintain the refrigerant at a constant temperature

A

To store the refrigerant after condensation

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35
Q

CONVERT 20 PSIG TO Hg ABSOLUTE

30

70

80

90

A

70

1 psig = 2.036 Hg. 70 is the closest to 40.36 without going over I guess

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36
Q

A “LIFT PUMP”

ACTUALLY LIFTS WATER TO THE PUMP SUCTION

IS LOCATED ABOVE THE SUCTION PIPE FEEDING IT

IS A PUMP THAT IS RELATIVELY LIGHT IN WEIGHT AND CAN BE LIFTED

IS A SAFETY PUMP USED TO PROTECT SYSTEM

A

ACTUALLY LIFTS WATER TO THE PUMP SUCTION

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37
Q

IF THE CHEMICAL TREATMENT WOULD BE TEMPORARILY UNAVAILABLE, YOU WOULD:

WEEKLY DRAIN THE TOWER AND SCRAPE CLEAN EVERYTHING

WEEKLY CHANGE ALL CONDENSER WATER

CHANGE FROM CITY WATER TO DISTILLED WATER

CHANGE THE BLEEDING SETTING OF THE TOWER WATER SO MORE BLEEDING WILL TAKE PLACE

A

CHANGE THE BLEEDING SETTING OF THE TOWER WATER SO MORE BLEEDING WILL TAKE PLACE

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38
Q

500 BTUs ARE REMOVED FROM 50 LBS. OF WATER AT 60°F, WHAT IS THE FINAL WATER TEMPERATURE?

40°F

50°F

60°F

70°F

A

50°F

500 BTU’s of heat is equal to 10F. 500 btus removed is equal to 10 degrees removed

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39
Q

THE UNIT USED TO MEASURE THE AMOUNT OF ELECTRONS FLOWING PAST A CERTAIN POINT IN AN ELECTRICAL CIRCUIT IS CALLED:

OHM

AMPERE

VOLT

WATT

NONE OF THE ABOVE

A

AMPERE

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40
Q

WHAT ARE THE RECOVERY REQUIREMENTS FOR LOW PRESSURE APPLIANCES

25” Hg

0 PSI

10” Hg

5” Hg

A

25” Hg

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41
Q

WHERE DO NON-CONDENSABLE VAPORS AND MOISTURE COLLECT?

LIQUID LINE

CONDENSER

EVAPORATOR

FILTER DRIER

A

CONDENSER

42
Q

WHAT ARE WEARING RINGS USED FOR?

TO PREVENT THE WEARING ON THE IMPELLER OR CASING

TO DECREASE THE TOLERANCE BETWEEN THE IMPELLER AND CASING

TO INCREASE EFFICIENCY

ALL OF THE ABOVE

A

ALL OF THE ABOVE

43
Q

AFTER OIL CIRCULATES IN A CENTRIFUGAL MACHINE, WHERE DOES THE OIL SETTLE AND HOW DO YOU EXTRACT IT OUT?

COMPRESSOR CRANKCASE AND DRAIN

OIL SUMP AND DRAIN FROM OIL VALVE

CONDENSER BOTTOM AND LIQUID SERVICE VALVE

EVAPORATOR AND EXTRACT FROM DRAIN VALVE

A

OIL SUMP AND DRAIN FROM OIL VALVE

44
Q

THE OUTLET FROM A FAN OR AIR DUCT USED TO VENTILATE REFRIGERANTS MUST BE AT LEAST _____ FEET FROM ANY AIR INTAKE OR EXHAUST OR ANY OPENINGS IN AN ADJOINING BUILDING

5

10

20

50

A

20

45
Q

HOW MANY BTUs ARE ABSORBED IN 5 TONS OF ICE?

188,000

2,200,000

1,440,000

NONE

A

1,440,000

Ice has a specific heat capacity of 0.5 BTU/lb F and it takes 144 BTU’s to melt 1 lb of ice

46
Q

REFRIGERANT OIL QUALITY IS MEASURED IN VISCOSITY, THE LEAST DESIRABLE QUALITY IN THE OIL WOULD BE:

HIGH VISCOSITY

SOUR TASTE

LOW VISCOSITY

NONE OF THE ABOVE

A

LOW VISCOSITY

47
Q

IF YOU ARE USING A RECOVERY MACHINE TO RECOVER REFRIGERANT FROM THE SYSTEM WITHOUT USING THE SYSTEM COMPRESSOR, WHAT KIND OF RECOVERY MACHINE IS THAT?

SELF CONTAINED

SELF DEPENDENT

CENTRIFUGAL RECOVERY MACHINE

NONE OF THE ABOVE

A

SELF CONTAINED

48
Q

HOW DOES A SOLENOID VALVE WORK?

OPEN A PLUNGER AND ALLOW REFRIGERANT IN

OPEN SPRING VALVE AND ALLOW REFRIGERANT IN

MANUALLY OPEN AND ALLOW REFRIGERANT IN

MANUALLY CLOSE AND PREVENT REFRIGERANT IN

A

OPEN A PLUNGER AND ALLOW REFRIGERANT IN

49
Q

THE AMOUNT OF VENTILATION FOR REFRIGERANT REMOVAL PURPOSES IN A MACHINE ROOM SHALL BE SIZED ACCORDING TO:

TOTAL AMOUNT OF REFRIGERANTS IN UNITS

AMOUNT OF THE MOST FLAMMABLE REFRIGERANT

AMOUNT OF REFRIGERANT IN LARGEST MACHINE

TOTAL AMOUNT OF REFRIGERANT IN UNITS AND STORED IN MACHINE ROOM

A

AMOUNT OF REFRIGERANT IN LARGEST MACHINE

50
Q

WHICH OF THE FOLLOWING BEST DESCRIBES THE NEED FOR USING A CASCADE SYSTEM?

TO INCREASE THE SYSTEMS COMPRESSION RATIO

TO DECREASE THE SYSTEMS COMPRESSION RATIO

TO OBTAIN LOW EVAPORATOR TEMPERATURES

TO PRODUCE ICE

A

TO OBTAIN LOW EVAPORATOR TEMPERATURES

51
Q

WHICH IS BEST TO USE WHEN SOLDERING COPPER, IRON OR STEEL?

BRAZING ALLOYS

ANY LOW TEMPERATURE SOLDER

50-50 TIN LEAD

SILVER SOLDER

A

SILVER SOLDER

52
Q

WHAT IS THE REASON TO PUT TWO LOW SIDE FLOATS IN PARALLEL?

YOU CAN MAKE A REPAIR WITHOUT INTERRUPTING THE OTHER

EACH ONE FEEDS ITS OWN EVAPORATOR

IF ONE CLOGS, FLOW WILL CONTINUE THROUGH THE SECOND

WHEN THE LOAD DECREASES IT WILL FEED FASTER

A

EACH ONE FEEDS ITS OWN EVAPORATOR

53
Q

WHAT IS THE PRESSURE OF R-22 AT 41°F?

38 PSIG

70 PSIG

18.5” Hg

81

A

70 PSIG

The pressure of R-22 at 41°F is 70 PSIG. This indicates that the refrigerant R-22 is at a pressure of 70 pounds per square inch gauge at a temperature of 41°F.

54
Q

ASIDE FROM VENTING REFRIGERANT FROM YOUR HOSE CONNECTIONS, THE ONLY OTHER TIME YOU MAY DISCHARGE REFRIGERANT WOULD BE?

WHEN A FIRE DEPT ENGINEER IS PRESENT

NEVER

AFTER THE FIRE DEPT ENGINEER LEAVES THE ROOM

TO CHECK IF THERE IS REFRIGERANT IN THE SYSTEM

A

NEVER

55
Q

IF REFRIGERANT OIL IS MEASURED TO HAVE A VISCOSITY AND THE VISCOSITY NUMBER IS LOW, WHAT DOES THAT MEAN?

DOESN’T FLOW

FLOWS EASILY, SMOOTHLY

FLOW IS SLOW

RESTRICTED FLOW

A

FLOWS EASILY, SMOOTHLY

56
Q

CENTRIFUGAL COMPRESSORS USE WHAT KIND OF REFRIGERANT?

CFCs

HIGH PRESSURE REFRIGERANT

LOW PRESSURE REFRIGERANT

ALL THE ABOVE

A

ALL THE ABOVE

57
Q

WATER WHEN MIXED WITH REFRIGERANT IN A RECIPROCATING SYSTEM WILL:

LUBRICATE THE SYSTEM

FORM ACIDS AND SLUDGE

CAUSE NON-CONDENSEABLES TO FORM

FREEZE UP IN CONDENSER

A

FORM ACIDS AND SLUDGE

58
Q

QUICK CONNECT FITTINGS ARE CONSIDERED AS:

LOW LOSS FITTINGS

SOLDERED FITTINGS

FLARE FITTINGS

AUTOMATIC LOSS FITTINGS

A

LOW LOSS FITTINGS

59
Q

WHAT IS THE ORDER OF COMPONENTS ON THE LIQUID LINE OF A RECIPROCATING SYSTEM FROM THE KING VALVE?

FILTER DRIER, SOLENOID VALVE, SIGHT GLASS, TEV TO EVAPORATOR

SOLENOID VALVE, FILTER DRIER, SIGHT GLASS, TEV TO EVAPORATOR

SIGHT GLASS, SOLENOID VALVE, FILTER DRIER, TEV TO EVAPORATOR

TEV, SIGHT GLASS, SOLENOID VALVE, FILTER DRIER TO EVAPORATOR

A

FILTER DRIER, SOLENOID VALVE, SIGHT GLASS, TEV TO EVAPORATOR

60
Q

WHEN IS A CENTRIFUGAL WATER PUMP CONSIDERED A “LIFT PUMP”?

WHEN THE SUCTION INLET OF THE WATER SOURCE IS BELOW THE PUMP LEVEL

WHEN THE DISCHARGE IS 120’ ABOVE

WHEN THE WATER IS LIFTED BY PUMP

WHEN THE PUMP WEIGHS LESS THAN 50 LBS.

A

WHEN THE SUCTION INLET OF THE WATER SOURCE IS BELOW THE PUMP LEVEL

61
Q

WHAT IS THE PURPOSE OF THE GLAND STEAM?

CREATE POSITIVE PRESSURE

ELIMINATE LEAKAGE AT THE END OF THE SHAFT

TO HEAT THE GLANDS

BOTH A AND B ARE CORRECT

A

BOTH A AND B ARE CORRECT

61
Q

WHEN OIL LEAVES THE SUMP IN A CENTRIFUGAL REFRIGERATION SYSTEM, WHERE DOES THE OIL GO?

TRAVELS WITH THE REFRIGERANT TO COOL THE REFRIGERATION SYSTEM

TRAVELS BACK TO THE OIL SUMP

IS COMPATIBLE WITH REFRIGERANT AND WILL TRAVEL THROUGH SYSTEM AND RETURN TO THE OIL SUMP

TRAVELS THROUGH THE SYSTEM AND IS DRAINED OUT OF THE SUMP BY A PETCOCK VALVE

A

TRAVELS BACK TO THE OIL SUMP

62
Q

THE RMO WANTS TO GET A TEMPERATURE READING FROM THE SUCTION LINE, BUT THERE ARE NO GAUGES:

THE RMO CAN TOUCH THE LINE AND USE HIS EXPERIENCE TO ESTIMATE WHAT THE TEMPERATURE IS

BUY A THERMOMETER AND STICK IT ON THE SUCTION LINE WITH PUTTY

GET TWO THERMOMETERS AND GET THE AVERAGE READINGS

TOUCH THE THERMOMETER ON THE SUCTION LINE AND GET A READING

A

BUY A THERMOMETER AND STICK IT ON THE SUCTION LINE WITH PUTTY

63
Q

WHAT IS THE AUXILIARY OIL PUMP USED FOR?

STARTING UP

LUBRICATING THE MAIN PUMP BEARINGS

ONLY USED WHEN MAIN PUMP IS MALFUCTIONING

USED IN RECPRROCATING MACHINES

A

STARTING UP

64
Q

IF YOU NEED TO ADD ANOTHER PUMP ONLINE, HOW DO YOU DO IT?

OPEN SUCTION SIDE VALVE AND PUT DISCHARGE IN THE THROTTLE POSITION

OPEN SUCTION, CLOSE DISCHARGE

CLOSE SUCTION, OPEN DISCHARGE

OPEN SUCTION AND SLOWLY FULLY OPEN DISCHARGE

A

OPEN SUCTION SIDE VALVE AND PUT DISCHARGE IN THE THROTTLE POSITION

65
Q

WHAT TYPE OF BEARING IS USED FOR TURBINE ROTOR SHAFT?

NEEDLE BEARING

SLEEVE BEARING

BALL BEARING

KINGSBURY BEARING

A

KINGSBURY BEARING

66
Q

A HALIDE TORCH IS TO BE USED OUTSIDE ON A ROOFTOP TO CHECK FOR LEAKS ON A REFRIGERATION UNIT. WHY SHOULD YOU NOT GENERALLY USE THIS DEVICE OUTSIDE?

RAIN CAN GET IN AND AFFECT ITS PERFORMANCE

WIND CAN AFFECT THE FLAME SIZE

YOU WILL NOT BE ABLE TO DETECT THE CHANGE IN COLOR DUE TO THE BRIGHTNESS OUTSIDE

OXYGEN OUTSIDE MAY CAUSE EXPLOSION

A

YOU WILL NOT BE ABLE TO DETECT THE CHANGE IN COLOR DUE TO THE BRIGHTNESS OUTSIDE

67
Q

THE PUMP SEAL PREVENTS WATER FROM LEAKING ON A CENTRIFUGAL WATER PUMP WHEN UNDER POSITIVE PRESSURE. WHAT OTHER FUNCTION MAY IT HAVE?

TO ALLOW WATER TO LEAK OFF WHEN USING MECHANICAL SEAL TYPE

SHOWS THAT WATER IS INSIDE WHEN IT IS DRIPPING

PREVENTS AIR FROM ENTERING WHEN IT IS UNDER NEGATIVE PRESSURE

STEAM CREATES POSITIVE PRESSURE TO PREVENT STEAM LEAKAGE

A

PREVENTS AIR FROM ENTERING WHEN IT IS UNDER NEGATIVE PRESSURE

68
Q

ON A VALVE PLATE, WHERE ARE THE SUCTION AND DISCHARGE VALVES LOCATED?

SUCTION ON TOP, DISCHARGE ON BOTTOM

SUCTION ON BOTTOM, DISCHARGE ON TOP

SUCTION AND DISCHARGE ON TOP

SUCTION AND DISCHARGE ON BOTTOM

A

SUCTION ON BOTTOM, DISCHARGE ON TOP

69
Q

BEFORE USING A VOLTMETER, THE TECHNICIAN SHOULD ALWAYS:

ZERO THE OHM ADJUSTMENT

TOUCH THE TWO LEADS TOGETHER TO ENSURE CONTINUITY

SET THE RANGE SELECTOR TO A SETTING HIGHER THAN THE VOLTAGE EXPECTED TO BE READ

TURN THE POWER OFF

NONE OF THE ABOVE

A

SET THE RANGE SELECTOR TO A SETTING HIGHER THAN THE VOLTAGE EXPECTED TO BE READ

70
Q

1000 BTUs OF HEAT IS ADDED TO 100 LBS. OF WATER. HOW MANY DEGREES DID THE TEMPERATURE OF WATER INCREASE?

10°C

10°F

1°C

1°F

A

10°F

When 1000 BTUs of heat is added to 100 lbs. of water, the temperature of the water increases by 10°F.

71
Q

THE CENTER PORT OF THE GAUGE MANIFOLD IS CONNECTED TO?

RECOVERY MACHINE

CHARGING CYLINDER

VACUUM PUMP

ALL OF THE ABOVE

A

ALL OF THE ABOVE

72
Q

HOW LONG DOES IT TAKE TO WARM UP A STEAM TURBINE?

15-20 MINUTES

30-40 MINUTES

NO LESS THAN 60 MINUTES

DOESN’T NEED WARM UP

A

15-20 MINUTES

73
Q

WHEN A THERMOSTATIC EXPANSION VALVE IS OPERATING PROPERLY, THE END OF THE COIL WILL CONTAIN

SATURATED VAPOR

SUPERHEATED VAPOR

LOW TEMPERATURE LIQUID

HOT VAPOR

A

SUPERHEATED VAPOR

74
Q

IF 10 BTUs IS TRANSFERRED TO 10 LBS. OF WATER, THE INCREASE IN TEMPERATURE IS CLOSEST TO:

10°F

10°C

1°F

1°C

A

1°F

75
Q

TO RAISE 10 LBS. OF WATER 1°F, HOW ANY BTUs DO YOU NEED?

1

5

20

10

A

10

To raise 10 lbs of water 1 degree F you need 10 BTUs

76
Q

LIQUID LEVEL GAUGES (EXCEPT BULL’S EYE TYPE) SHALL HAVE SHUT OFF VALVES:

MANUAL ONLY

AUTOMATIC ONLY

VALVES NOT NEEDED

MANUAL AND AUTOMATIC

A

MANUAL AND AUTOMATIC

77
Q

WHEN YOU ARE FINISHED LEAK TESTING WITH NITROGEN AND R-22, THEN THE NEXT STEP WOULD BE:

VENT REFRIGERANT AND NITROGEN TO OPEN AIR

REMOVE REFRIGERANT AND NITROGEN AT RECOVERY MACHINE

ADD REFRIGERANT

ADD REFRIGERANT IF NEEDED AND PUT SYSTEM BACK ONLINE

A

VENT REFRIGERANT AND NITROGEN TO OPEN AIR

78
Q

WHAT WOULD BEST DESCRIBE THE REFRIGERANT IN THE LAST EVAPORATOR COIL?

VAPOR

SATURATED VAPOR

SUPERHEATED VAPOR

DRY VAPOR

A

SUPERHEATED VAPOR

78
Q

WHAT IS A SUPERHEATED VAPOR?

VERY HIGH TEMPERATURE GAS MIXED WITH LIQUID

DRY VAPOR

DRY VAPOR AT ITS BOILING POINT

DRY VAPOR ABOVE ITS BOILING POINT

A

DRY VAPOR ABOVE ITS BOILING POINT

79
Q

A RECIPROCATING COMPRESSOR SHAFT SEAL IS MADE UP OF:

PLASTIC

RUBBER

GRAPHITE FIBER HEMP

METAL

A

METAL

80
Q

WHAT IS THE MAIN DISADVANTAGE OF THE SUCTION LINE FILTER DRIER COMPARED TO THE LIQUID LINE FILTER DRIER?

SUCTION LINE FILTER DRIER IS HARDER TO CHANGE THAN THE LIQUID LINE FILTER DRIER

IS LESS EFFICIENT THAN THE LIQUID LINE FILTER DRIER DUE TO DENSITY OF REFRIGERANT

SUCTION LINE FILTER DRIER IS TOO BIG AND BULKY

IF IT GETS CLOGGED THE SUCTION LINE FILTER DRIER REDUCES MORE OF THE CAPACITY OF THE COMPRESSOR THAN THE LIQUID LINE FILTER DRIER

A

IF IT GETS CLOGGED THE SUCTION LINE FILTER DRIER REDUCES MORE OF THE CAPACITY OF THE COMPRESSOR THAN THE LIQUID LINE FILTER DRIER

80
Q

ON A CENTRIFUGAL WATER PUMP THE CONDITIONS ARE CORRECTLY PRIMED WHEN:

IT IS FULL OF WATER AND ALL AIR HAS BEEN PURGED OUT

WATER IS LEAKING FROM THE PACKING

THE PACKING WILL MAINTAIN THE WATER IN THE PUMP

NO REFRIGERANT IS LEAKING

A

IT IS FULL OF WATER AND ALL AIR HAS BEEN PURGED OUT

81
Q

WHY CAN’T YOU USE A FLARE FITTING 3/4” OR LARGER?

CAN’T FLARE THAT LARGE

CAN’T TIGHTEN TO GET A GOOD SEAL

AGAINST THE LAW

EASIER TO SWEAT

A

CAN’T TIGHTEN TO GET A GOOD SEAL

82
Q

AN OPEN TYPE COMPRESSOR IS KEEPING THE REFRIGERANT FROM ESCAPING BY TIGHTENING A SEAL MADE OF:

RUBBER

GRAPHITE LOADED FIBER

CARBON AND METAL

FORTIFIED PLASTIC

A

CARBON AND METAL

83
Q

AFTER LEAK DETECTING WITH MOISTURE OF NITROGEN AND A TRACE OF R-22, THE RMO:

HAS TO RECOVER ONLY THE R-22

CAN VENT THE MIXTURE TO THE ATMOSPHERE

RECOVER BOTH INTO THE SAME CONTAINER

RECOVER BOTH, BUT IN SEPARATE CYLINDERS

A

CAN VENT THE MIXTURE TO THE ATMOSPHERE

84
Q

IF YOU HAVE A 3 LINE CABLE SUPPLYING ENERGY TO YOUR EQUIPMENT, AND ONLY TWO LINES HAVE FUSES, THE UNFUSED LINE WOULD BE?

CONNECT THE EXTRA LINE TO MAKE 3 PHASE

2 UNFUSED WIRES DO NOT NEED TO BE INSULATED

THE NEUTRAL LINE OF A 120/240 CIRCUIT

THIS WOULD PRESENT AN UNSAFE CONDITION

A

THE NEUTRAL LINE OF A 120/240 CIRCUIT

85
Q

WHAT IS THE TOTAL MAXIMUM AMOUNT OF REFRIGERANT YOU CAN STORE IN THE MACHINERY ROOM APART FROM YOUR REFRIGERANT IN YOUR MACHINE?

100 LBS

150 LBS

300 LBS

5 DRUMS

A

300 LBS

85
Q

WHAT INFORMATION MUST BE STAMPED ON A FUSIBLE PLUG?

TYPE OF REFRIGERANT IT CAN BE USED WITH

MELTING POINT OF ALLOY

RELEASE PRESSURE

RESET PRESSURE

A

MELTING POINT OF ALLOY

86
Q

WHEN WATER TURNS TO ICE, WHAT TAKES PLACE?

SUPERHEAT

HEAT OF FUSION

HEAT OF EVAPORATION

SUBCOOLING

A

HEAT OF FUSION

87
Q

WHICH OF THE FOLLOWING ELECTRICAL COMPONENTS HAVE THE ABILITY TO STORE ELECTRICITY AND ARE SOMETIMES USED TO START MOTORS?

RESISTOR

RECTIFIER

GENERATOR

CAPACITOR

A

CAPACITOR

88
Q

WHY IS GLYCOL A BETTER BRINE THAN SODIUM CHLORIDE?

MORE CONDUCTIVE

COST LESS

NO CORROSION

HIGHER FREEZING POINT

A

NO CORROSION

89
Q

YOU ARE AN RMO AND YOU START THE MACHINE AND THE MACHINE DOESN’T START. YOUR FUSES, CIRCUIT BREAKERS AND ELECTRICAL COMPONENTS ARE ALL GOOD. WHAT WOULD YOU CHECK NEXT?

SIGHTGLASS

THERMOSTAT

LOW PRESSURE CUT OUT, PRESSURE SWITCH

REFRIGERANT CHARGE

A

LOW PRESSURE CUT OUT, PRESSURE SWITCH

90
Q

WHAT IS USED TO TRACK SPEED IN A STEAM TURBINE?

TACHOMETER

SPEEDOMETER

PEDOMETER

TRACKOMETER

A

TACHOMETER

91
Q

YOU ARE USING COPPER TUBING TO REPLACE A PART OF A REFRIGERATION SYSTEM. WHAT IS USED TO BEND THE TUBING?

PIPE HICKEY

SPRING TYPE TUBE BENDER

VISE

PINCH BAR

A

SPRING TYPE TUBE BENDER

92
Q

YOU ARE A RMO AND YOU WANT TO WORK ON THE MACHINES PRESSURE RELIEF VALVE ON A DUAL PRESSURE RELIEF VALVE SYSTEM. WHAT VALVE WOULD YOU INSTALL TO WORK ON ONE PRESSURE RELIEF VALVE WHILE ALLOWING THE OTHER ONE TO OPERATE IN THE SYSTEM?

GATE VALVE

BUTTERFLY VALVE OR PLUG VALVE

TWO WAY VALVE

THREE WAY VALVE

A

THREE WAY VALVE

93
Q

THE TRUE POWER CONSUMED BY AN INDUCTION MOTOR CAN BEST BE DESCRIBED BY THE FOLLOWING FORMULA:

CURRENT x VOLTAGE x POWER FACTOR

CURRENT x VOLTAGE

VOLTAGE x RESISTANCE

CURRENT x RESISTANCE

A

CURRENT x VOLTAGE x POWER FACTOR

94
Q

WHAT DOES A FILTER DRIER DO?

REMOVES PARTICLES

REMOVES MOISTURE

REMOVES ACID

ALL OF THE ABOVE

A

ALL OF THE ABOVE

95
Q

A COMPRESSOR THAT USES A SHAFT WITH A MECHANICAL SEAL, WHAT IS THE VALVE PLATE MADE OF?

METAL/CARBON

PLASTIC

RUBBER

SILICON

A

METAL/CARBON

96
Q

REGARDLESS OF THE SAFETY CLASSIFICATION OF THE REFRIGERANT IN USE, IN THE EVENT OF REFRIGERANT ESCAPE, THE RMO SHOULD BE AWARE OF:

A REFRIGERANT FIRE

REFRIGERANT POISONING

OXYGEN DEPRIVATION

ATMOSPHERIC SUPERHEATING

A

OXYGEN DEPRIVATION

97
Q

Pass

A

Refrigerant Machine Operator Practical (5 decks)

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