Refrigerant Machine Operator Certification Practice Test

100 Questions | Total Attempts: 10865

SettingsSettingsSettings
Please wait...
Refrigerant Machine Operator Certification Practice Test

Industrial refrigerant machine operators seem to be simple people within the production chain but essentially are very important. Take up the quiz below and see how good you are as a refrigerant machine operator. This test consists of 100 most important questions that will help you clear the certification exam of the same. All the best.


Questions and Answers
  • 1. 
    YOU HAVE BEEN INFORMED THAT THE O.A.T. HAS DROPPED 10°C. THE TEMPERATURE IN °F IS
    • A. 

      32

    • B. 

      28

    • C. 

      40

    • D. 

      18

  • 2. 
    YOU ARE AN RMO ASSIGNED TO THE 3RD FLOOR IN AN ASSEMBLY ROOM. ATTENDANCE AND TEMP HAVE INCREASED DURING THE AFTERNOON, THEREFORE A COLDER WATER SUPPLY IS TO BE PRODUCED. IN ORDER TO ACCOMPLISH THIS YOU SHOULD:
    • A. 

      RE-ADJUST THE TEV SUPERHEAT SETTING

    • B. 

      DEACTIVATE THE FREEZE STAT

    • C. 

      RAISE THE COMPRESSOR DISCHARGE OPERATING PRESSURE

    • D. 

      LOWER THE COMPRESSOR SUCTION OPERATING PRESSURE

  • 3. 
    YOU ARE AN RMO ASSIGNED TO FACILITY WHERE A REFRIGERANT HAS BEEN RECENTLY CHANGED FROM A FLAMMABLE REFRIGERANT TO R-22, AT THE MOMENT YOU ARE PLANNING TO BRAZE METAL.  ON SUCH MAKING A REPAIR IN THE MACHINERY ROOM, UNDER THESE CIRCUMSTANCES YOU:
    • A. 

      MUST ENSURE THE FLAME IS ENCLOSED AND VENTED TO OPEN AIR

    • B. 

      MAY MAKE REPAIRS AT LEAST 25 FEET FROM THE REFRIGERANT UNIT

    • C. 

      MAY MAKE REPAIRS WITHOUT ANY RESTRICTIONS IF THE REFRIGERATING UNIT IS SHUT DOWN

    • D. 

      MAY NOT MAKE REPAIR UNDER ANY CIRCUMSTANCES

  • 4. 
    WITH RESPECT TO FIRE SAFETY, THE ANSI/ASHRAE REFRIGERANT SAFETY CLASSIFICATION THAT IS MOST DANGEROUS IS
    • A. 

      A1

    • B. 

      B2

    • C. 

      A3

    • D. 

      B1

  • 5. 
    WHY SHOULD YOU CHARGE WITH VAPOR?
    • A. 

      YOU COULD BREAK THE RUPTURE GUARD WITH LIQUID

    • B. 

      YOU CAN ENTRAIN THE OIL IN THE REFRIGERANT WITH LIQUID

    • C. 

      YOU CAN FREEZE WATER IN THE TUBES WITH LIQUID

    • D. 

      YOU CAN OVER CHARGE THE SYSTEM WITH LIQUID

  • 6. 
    WHY IS SPRING LOADED PRV BETTER TO USE THAN A FUSIBLE PLUG?
    • A. 

      LESS EXPENSIVE

    • B. 

      EASY AVAILABILITY

    • C. 

      FUSIBLE PLUG CANNOT RESET

    • D. 

      LARGER

  • 7. 
    WHILE MONITORING THE OPERATION OF A RECIPROCATING REFRIGERATING UNIT YOU OVERSEE THAT THE CYCLING TIMES ARE NORMAL, COMPRESSOR COMPRESSION AND TEMP ARE THE ONLY READING THAT ARE OUTSIDE THE NORMAL RATE. UNDER THESE CONDITIONS SERVICE REQUIREMENTS WOULD INDICATE INSPECTING FOR
    • A. 

      FAULTY MACHINE CONTROL

    • B. 

      PROPER REFRIGERATION CHARGE

    • C. 

      FAULTY COMPRESSOR VALVES

    • D. 

      POOR CONDENSER OPERATION / DIRTY TUBES

  • 8. 
    WHICH TYPE OF PUMP IS CONSIDERED A NON-POSITIVE DISPLACEMENT PUMP?
    • A. 

      RECIPROCATING

    • B. 

      ROTORY, SCREW

    • C. 

      SCROLL

    • D. 

      CENTRIFUGAL

  • 9. 
    WHICH OF THE FOLLOWING ASHRAE SAFETY GROUPS IS THE MOST DANGEROUS?
    • A. 

      A1

    • B. 

      A2

    • C. 

      B2

    • D. 

      B3

  • 10. 
    WHICH IS NOT USED AS A COOLING MEDIUM IN AN INDIRECT SYSTEM
    • A. 

      R-22

    • B. 

      CALCIUM CHLORIDE

    • C. 

      GLOCOL

    • D. 

      SODIUM CHLORIDE

  • 11. 
    WHEN PROPERLY PURGING YOU SHOULD
    • A. 

      PURGE AT RAPID RATE

    • B. 

      PURGE WITH COMPRESSOR ON

    • C. 

      STOP WHEN PRESSURE CEASES TO DROP

    • D. 

      RUN THE CONDENSER AS MUCH AS POSSIBLE

  • 12. 
    WHEN OPERATING A REFRIGERATION UNIT, THE OPERATOR NOTICES THAT THE MOTOR COMPRESSOR IS SHORT CYCLING, THE UNIT IS USING A LOW SIDE FLOAT VALVE.  THE FOLLOWING SERVICE REQUIREMENTS WOULD INDICATE
    • A. 

      INSPECTION SHOULD BE MADE FOR DIRTY TEV STRAINER

    • B. 

      PARTIALLY CLOGGED DISCHARGE LINE

    • C. 

      CHECK COMPRESSOR WIRING, FOR OVERLOADED EQUIPMENT

    • D. 

      ADDITIONAL REFRIGERANT BE CHARGED

  • 13. 
    WHEN OPERATING A REFRIGERATION MACHINE CONDENSER USING R-22 REFRIGERANT, UNDER NORMAL CONDITIONS THE OPERATOR OBSERVES THAT THE COOLING WATER IS BEING SUPPLIED AT 85°F AND LEAVING AT 95°F.  GIVEN THIS INFORMATION, THE CORRESPONDING COMPRESSOR HEAD PRESSURE IN PSI SHOULD BE MOST NEARLY:
    • A. 

      113

    • B. 

      313

    • C. 

      213

    • D. 

      13

  • 14. 
    WHEN INSTALLING A SERVICE VALVE TO ISOLATE A DUAL PRESSURE DEVICE WHILE KEEPING SYSTEM IN SERVICE, YOU WOULD USE A 
    • A. 

      TWO WAY VALVE

    • B. 

      THREE WAY VALVE

    • C. 

      PLUG VALVE

    • D. 

      STOP VALVE

  • 15. 
    WHEN INSTALLING A PIPELINE AND YOU NEED TO MAKE A 90° ELBOW, WHICH IS THE BEST WAY?
    • A. 

      BEND PIPE

    • B. 

      USE FACTORY MADE 90° ELBOW AND BRAZE

    • C. 

      USE FLEXIBLE TUBING

    • D. 

      USE TWO 45° ELBOWS

  • 16. 
    WHEN CONDUCTING A ROUTINE TOUR OF PLANT OPERATION A RMO OBSERVES A SIGNIFICANT INCREASE IN SUPERHEAT TEMP.  FOR THE REFRIGERATING FLUID ENTERING A RECIPROCATING COMPRESSOR.  OF THE FOLLOWING THE MOST LIKELY CAUSE FOR THIS CONDITION IS
    • A. 

      SCALE PARTICLES LODGED IN THE TEV VALVE

    • B. 

      UNRAVELING OF THE INSULATION PROTECTING THE TEV VALVE THERMAL BULB

    • C. 

      BUILD-UP OF NONCONDENSABLES IN THE CONDENSER

    • D. 

      OVERCHARGE OF REFRIGERANT

  • 17. 
    WHEN CHARGING AN R-12 RECIPROCATING REFRIGERATION SYSTEM, AN OPERATOR WOULD WANT TO USE WARM WATER TO INCREASE THE RELEASE RATE OF REFRIGERANT FROM THE DRUM.  TO PERFORM THIS OPERATION THE WATER TEMP. SHOULD NOT EXCEED THE DEGREE °F OF
    • A. 

      80°F

    • B. 

      90°F

    • C. 

      110°F

    • D. 

      130°F

  • 18. 
    • A. 

      HIGH AND LOW VALVES BACKSEATED

    • B. 

      HIGH AND LOW VALVES FRONTSEATED

    • C. 

      HIGH SIDE BACKSEATED, LOW SIDE FRONTSEATED

    • D. 

      HIGH SIDE FRONTSEATED, LOW SIDE BACKSEATED

  • 19. 
    WHEN CHANGING WATER TO ICE, WHAT MUST BE REMOVED?
    • A. 

      SPECIFIC HEAT

    • B. 

      SUPER HEAT

    • C. 

      LATENT HEAT

    • D. 

      SENSIBLE HEAT

  • 20. 
    WHAT WOULD HAPPEN IF THE SPRING IN THE TEV WERE TO BREAK?
    • A. 

      FLOOD THE EVAPORATOR

    • B. 

      STARVE THE EVAPORATOR

    • C. 

      NO CHANGE

    • D. 

      DAMAGE FEELER BULB

  • 21. 
    WHAT SAFETY GROUP DOES AMMONIA BELONG?
    • A. 

      GROUP 2, B2

    • B. 

      GROUP 1, A1

    • C. 

      GROUP 3, B1

    • D. 

      BOTH A1 AND B1

  • 22. 
    WHAT REFRIGERANT SYSTEMS ARE MOST LIKELY TO LEAK REFRIGERANT IN BUILDING SPACES THAT ARE BEING COOLED?
    • A. 

      INDIRECT SYSTEMS

    • B. 

      DIRECT SYSTEMS

    • C. 

      INDIRECT CLOSED SYSTEMS

    • D. 

      INDRIECT OPEN SYSTEMS

  • 23. 
    WHAT IS THE TEV DIAPHRAM MADE OF
    • A. 

      RUBBER

    • B. 

      METAL

    • C. 

      PLASTIC

    • D. 

      GRAPHITE

  • 24. 
    WHAT IS THE PURPOSE OF THE EQUALIZER LINE?
    • A. 

      TO EQUALIZE PRESSURE IN THE TEV ALONG THE DIAPHRAM AND BELLOWS

    • B. 

      TO MAKE UP FOR THE PRESSURE DROP IN EVAPORATOR

    • C. 

      TO METER REFRIGERANT

    • D. 

      TO REMOVE PRESSURE DROP

  • 25. 
    WHAT IS THE DISADVANTAGE OF HAVING A LOW HEAD PRESSURE?
    • A. 

      EVAPORATOR WOULD FLOOD

    • B. 

      COMPRESSOR WOULD HUNT

    • C. 

      EXPANSION VALVE WOULD NOT FEED PROPERLY

    • D. 

      CONDENSER COULD NOT SUB-COOL

  • 26. 
    WHAT IS PURPOSE OF HAVING A SERVICE VALVE STEM CAP?
    • A. 

      TO PROTECT FROM BEING INADVERTENTLY TURNED FROM ITS POSITION AND FROM BEING DAMAGED

    • B. 

      TO LET YOU KNOW THE POSITION OF THE VALVE

    • C. 

      TO LET YOU NOTICE VALVE FROM A DISTANCE

    • D. 

      TO CAP OFF VALVE SO THAT UT CAN NEVER BE USED

  • 27. 
    UPON BEING ASSIGNED TO A FACILITY DURING INSPECTION OF THE FACILITY, YOU FIND THERE HAS BEEN FAILURE TO MAINTAIN WATER TREATMENT.  INSPECTING THE CONDENSER WATER, THE FIRST EVIDENCE WOULD MOST LIKELY BE:
    • A. 

      DECREASE IN SUPER HEAT TEMP ENTERING COMPRESSOR

    • B. 

      AN INCREASE IN COMPRESSOR HEAD PRESSURE

    • C. 

      AN INCREASE IN THE FLOW RATE OF NONCONDENSABLES

    • D. 

      CONDENSER TO METERING DEVICE FROZEN

  • 28. 
    UNLOADERS ARE USED TO:
    • A. 

      INCREASE CAPACITY

    • B. 

      STOP FLOW OF REFRIGERANT WITHOUT STOPPING

    • C. 

      REDUCE CAPACITY

    • D. 

      START FLOW OF REFRIGERANT THROUGH SYSTEM

  • 29. 
    TXV POWER HEADS ARE COLOR CODED TO MATCH REFRIGERANT CHARGE IN THE SYSTEM.  WHAT COLOR WOULD THE POWER HEAD HAVE IF IT WAS CHARGE WITH R-22?
    • A. 

      ORANGE

    • B. 

      GREEN

    • C. 

      YELLOW

    • D. 

      WHITE

  • 30. 
    THE SOLENOID UNLOADERS ON RECIPROCATING COMPRESSORS ARE DESIGNED TO UNLOAD:
    • A. 

      ALL THE CYLINDERS

    • B. 

      THE CLEARANCE SPACES IN THE CYLINDERS

    • C. 

      CONTROL CAPACITY BY SHUTTING DOWN THE COMPRESSOR

    • D. 

      CYLINDERS THAT CAN BE UNLOADED

  • 31. 
    THE BULB TO A TXV HAS FALLEN OFF AND THE ROOM IS AT 85°F.  THE EVAPORATOR WOULD?
    • A. 

      STARVE

    • B. 

      FLOOD

    • C. 

      INCREASE SUPERHEAT

    • D. 

      RESPOND NORMALLY

  • 32. 
    THE AMOUNT OF REFRIGERANT THAT FLOWS THROUGH THE ORIFICE PLATE IS DETERMINED BY:
    • A. 

      THE NUMBER OF ECONOMIZER STAGES

    • B. 

      THE NUMBER OF COMPRESSION STAGES

    • C. 

      TEMPERATURE OF REFRIGERANT IN THE HIGH SIDE

    • D. 

      DIFFERENCE IN PRESSURE BETWEEN HIGH AND LOW SIDES

  • 33. 
    SUPERHEATED VAPOR PROTECTS THE COMPRESSOR AGAINST LIQUID INTAKE.  WHAT WOULD THE RMO NOTICE IF COMPRESSOR WAS RECEIVING LIQUID?
    • A. 

      HEAD PSI DROPPING TO LOW

    • B. 

      DECREASE THE CAPACITY OF THE COMPRESSOR AND REFRIGERATION SYSTEM

    • C. 

      NON-CONDENSABLES ARE MORE PRONE TO COLLECT IN THE SYSTEM

    • D. 

      FROST MAY DEVELOP IN THE SUCTION LINE

  • 34. 
    SEMI-HERMETIC COMPRESSORS MAY BE BETTER TO USE THAN HERMETIC COMPRESSORS BECAUSE HERMETIC COMPRESSORS:
    • A. 

      ARE FULLY ENCLOSED AND CANNOT BE SERVICED ON SITE

    • B. 

      ARE EASIER TO GET TO

    • C. 

      ARE MORE DIFFICULT TO GET TO

    • D. 

      ARE MORE EXPENSIVE

  • 35. 
    REFRIGERANTS ARE CHARACTERIZED BY THE PHYSICAL AND CHEMICAL PROPERTIES INCLUDING LATENT HEAT, BOILING POINT, REFRIGERATION EFFECT AND OTHERS.  OF THE REFRIGERANTS IN COMMERCIAL INDUSTRIES USED TODAY, THE ONE WITH THE HIGHEST LATENT HEAT AND REFRIGERATION EFFECT:
    • A. 

      R-12

    • B. 

      CARBON DIOXIDE

    • C. 

      AMMONIA

    • D. 

      R-22

  • 36. 
    R-22 IS:
    • A. 

      ODORLESS

    • B. 

      ETHER LIKE ODER WHEN MIXED WITH AIR

    • C. 

      EXPLOSIVE

    • D. 

      BOILS AT A HIGHER TEMPERATURE THAN R-12

  • 37. 
    R-11 AND R-123 REFRIGERANTS ARE
    • A. 

      OXYGEN DEPLETING

    • B. 

      HEAVIER THAN AIR

    • C. 

      ARE CLASS-1 AND CLASS-2 SUBSTANCES DEFINED BY EPA

    • D. 

      ALL OF THE ABOVE

  • 38. 
    ORIFICE PLATES MAY BE USED AS A METERING DEVICE COMPONENT IN A CENTRIFUGAL SYSTEM.  THE VESSEL WHICH THEY ARE CONTAINED IN CAN ALSO SERVE AS
    • A. 

      VAPOR RECYCLING UNIT

    • B. 

      AN ECONOMIZER

    • C. 

      REFRIGERANT CLEANER

    • D. 

      EVAPORATOR

  • 39. 
    ONE DISADVANTAGE IN USING BRINES AS A COOLING MEDIUM IS CORROSION.  IN COMMERCIAL PRACTICE CORROSION AND THE AMOUNT OF RUST FORMED IS REDUCED BY THE ADDITION TO THE BRINE SOLUTION OF:
    • A. 

      WEAK ACID SOLUTION

    • B. 

      ZINC COMPOUNDS

    • C. 

      GLYCOLS

    • D. 

      DI-CHROMATES

  • 40. 
    ON THE LIQUID LINE, WHICH IS THE CORRECT ORDER OF THE PLACEMENT OF ACCESSORIES?
    • A. 

      SOLENOID VALVE, SIGHT-GLASS, AND DRIER

    • B. 

      DRIER, SIGHT-GLASS, AND SOLENOID VALVE

    • C. 

      DRIER, SOLENOID VALVE, AND SIGHT-GLASS

    • D. 

      NONE OF THE ABOVE

  • 41. 
    OF THE FOLLOWING, WHICH REFRIGERANT REQUIRES THE APPROVAL FOR USE BY THE NYC FIRE DEPT?
    • A. 

      R-22

    • B. 

      R-12

    • C. 

      CARBON DIOXIDE

    • D. 

      BUTANE

  • 42. 
    OF THE FOLLOWING, UNDER WHAT CONDITIONS OF THE HEAT IN BTU/PER MIN ABSORBED BY THE CONDENSER WATER IN A REFRIGERATING PLANT IS GREATER?
    • A. 

      AT HIGHER EVAPORATIVE TEMPERATURE AND LOW CONDENSER TEMPERATURE

    • B. 

      LOW EVAPORATIVE TEMPERATURE AND HIGH CONDENSER TEMPERATURE

    • C. 

      HIGHER EVAPORATIVE TEMPERATURE AND HIGH CONDENSER TEMPERATURE

    • D. 

      LOW EVAPORATIVE TEMPERATURE AND LOW CONDENSER TEMPERATURE

  • 43. 
    OF THE FOLLOWING THE MOST UNDESIRABLE PROPERTY IN REFRIGERANT IS
    • A. 

      LOW CORRESPONDING COMPRESSOR DISCHARGE TEMP

    • B. 

      LOW VISCOSITY

    • C. 

      LOW LATENT HEAT

    • D. 

      LOW CORRESPONDING OPERATING PRESSURE

  • 44. 
    OF THE FOLLOWING THE MOST CORRECT WAY TO DESCRIBE A BRAZED JOINT IS
    • A. 

      PRESSURE FITTING

    • B. 

      GAS TIGHT FITTING

    • C. 

      START TO MELT AT 400°F

    • D. 

      START TO MELT AT 500°F

  • 45. 
    OF THE FOLLOWING THE MOST COMMON METERING DEVICE USED TODAY IN A RECIPROCATING COMMERCIAL REFRIGERATION SYSTEM OVER 3 TONS IS
    • A. 

      AUTOMATIC EXPANSION VALVE

    • B. 

      THERMOSTATIC EXPANSION VALVE

    • C. 

      LOW SIDE FLOAT

    • D. 

      HIGH SIDE FLOAT

  • 46. 
    • A. 

      TIP SPEED IS MORE WITH EACH STAGE

    • B. 

      EVERY STAGE IS IDENTICAL

    • C. 

      HANDLES MORE REFRIGERANT

    • D. 

      HAS SMALLER VOLUME

  • 47. 
    MACHINE ROOM SAFETY STANDARDS HAVE BEEN ESTABLISHED BY
    • A. 

      ARI-700

    • B. 

      ARI-740

    • C. 

      ASHRAE 34

    • D. 

      ASHRAE 15

  • 48. 
    LOW CONDENSING PRESSURE IS NOT GOOD BECAUSE
    • A. 

      LIQUID LEVEL IN CONDENSER WILL FALL TOO LOW

    • B. 

      COMPRESSOR WILL WORK HARDER

    • C. 

      EXPANSION VALVES WILL NOT FEED PROPERLY

    • D. 

      HEAD PRESSURE WILL INCREASE

  • 49. 
    IN AN OPERATING PLANT USING RECIPROCATING COMPRESSORS, THE EFFICIENCY OF ONE OF THE COMPRESSORS HAS DECREASED.  ONE OF THE FOLLOWING MAY BE THE CAUSE OF THIS
    • A. 

      LIGHT SUCTION VALVE SPRINGS

    • B. 

      HIGH SUCTION PRESSURE

    • C. 

      LEAK IN THE SUCTION VALVE

    • D. 

      LOW SUCTION PRESSURE

  • 50. 
    IN AN EMERGENCY IF YOU MUST DUMP REFRIGERANT INTO SEWER, YOU WILL DUMP ONLY WHEN
    • A. 

      SEWER IS NOT CONNECTED TO A STORM DRAIN

    • B. 

      FIRST CONFIRM THAT REFRIGERANT IS NOT FLAMMABLE

    • C. 

      FACILITY MANAGER APPROVES IT

    • D. 

      YOU DISCHARGE UNDER THE SUPERVISION OF THE FIRE DEPT.

  • 51. 
    IN A REFRIGERATION PLANT, A SMALL INDUCTION REFRIGERATION MOTOR IS RUNNING ON AC CURRENT.  IN ORDER FOR THE OPERATOR TO DETERMINE THE TRUE POWER CONSUMPTION, ASSUMING THAT IF EVERY ELIGIBLE CHARACTERISTICS HAVE BEEN MEANT, OF THE FOLLOWING THE POWER CONSUMPTION IS DETERMINED BY THE APPLICATION OF THE FORMULA:
    • A. 

      WATTS = VOLTS X AMPS X OHMS

    • B. 

      WATTS = VOLTS X AMPS X HERTZ

    • C. 

      WATTS = VOLTS X AMPS

    • D. 

      WATTS = VOLTS X AMPS X POWER FACTOR

  • 52. 
    IN A COMPRESSOR'S ELECTRICAL BOX ONE OF THE HOT WIRES IS TOUCHING THE METAL BOX, WHAT WOULD MOST LIKELY HAPPEN?
    • A. 

      COMPRESSOR WOULD OVERHEAT

    • B. 

      COMPRESSOR WOULD OVERLOAD AND SHUT OFF

    • C. 

      RMO WORKERS CAN RECEIVE ELECTRIC SHOCK IF THEY TOUCH IT

    • D. 

      NOTHING

  • 53. 
    IF YOU WERE RUNNING THREE COMPRESSORS, WHICH BEST DESCRIBES THE STATE OF REFRIGERANT LEAVING THE THIRD COMPRESSOR?
    • A. 

      MOSTLY LIQUID, SOME VAPOR

    • B. 

      MOSTLY VAPOR, SOME LIQUID

    • C. 

      SLIGHTLY SUPERHEATED VAPOR

    • D. 

      HIGHLY SUPERHEATED VAPOR

  • 54. 
    IF YOU JUST PURCHASED A THERMOMETER AND NEED TO CHECK TO SEE IF ITS WORKING PROPERLY, HOW WOULD YOU DO IT?
    • A. 

      TOUCH IT IN A POT OF BOILING WATER

    • B. 

      TOUCH IT TO BUCKET OF ICE / ICE WATER

    • C. 

      COMPARE TO 2 OTHER THERMOMETERS

    • D. 

      COMPARE TO ANOTHER RMO THERMOMETER

  • 55. 
    IF YOU ARE USING A PORTABLE COMPRESSOR RECOVERY UNIT TO REMOVE VAPOR.  WHAT WOULD HAPPEN WHEN YOU ARE RECOVERING?
    • A. 

      COMPRESSOR SPEED IS DECREASED

    • B. 

      VAPOR DENSITY IS DECREASED

    • C. 

      REFRIGERANT TEMPERATURE WILL DROP

    • D. 

      COMPRESSOR EFFICIENCY WILL DECREASE

  • 56. 
    IF THE SUCTION PRESSURE IS 60 PSIG AND THE DISCHARGE 180 PSIG, WHAT WOULD THE COMPRESSION RATIO BE?
    • A. 

      5:1

    • B. 

      3:1

    • C. 

      2:6:1

    • D. 

      .3:1

  • 57. 
    IF THE ELIMINATOR PLATES LOCATED BELOW THE FAN IN AN INDUCED DRAFT-COOLING TOWER HAVE BECOME CLOGGED, OF THE FOLLOWING THIS WOULD MOST LIKELY RESULT IN: 
    • A. 

      DAMAGE TO FAN BLADES

    • B. 

      INCREASE IN COOLING TOWER WATER TEMP BEING RETURNED

    • C. 

      DECREASE IN MAKEUP WATER REQUIREMENTS

    • D. 

      A DROP IN WET BULB TEMP

  • 58. 
    IF AN ELECTRIC MOTOR IS REWOUND TO CUT RESISTANCE BY 1/2, ALL OTHER FACTORS BEING EQUAL, THE MOTOR POWER WOULD:
    • A. 

      REDUCE BY 1/2

    • B. 

      INCREASE BY A FACTOR OF 2

    • C. 

      STAY THE SAME

    • D. 

      INCREASE BY A FACTOR OF 4

  • 59. 
    IF A CENTRIFUGAL COMPRESSOR IS BEING USED IN A REFRIGERATION SYSTEM, AND IS AFFECTED BY THE CONDENSER, THE CONDENSER MAY BE IMPROVED BY:
    • A. 

      INCREASING THE AMOUNT OF SUPERHEAT

    • B. 

      INCREASING THE AMOUNT OF SUB-COOLING

    • C. 

      DECREASE THE AMOUNT OF SUPERHEAT

    • D. 

      DECREASE THE AMOUNT OF SUB-COOLING

  • 60. 
    HEAT TRANSFER RATE IN THE CONDENSER WILL
    • A. 

      INCREASE WITH THE VELOCITY OF THE WATER IN THE TUBES

    • B. 

      SHOW ONLY A SMALL INCREASE IF TUBES ARE DESCALED

    • C. 

      INCREASE WITH A LOWER LEAVING WATER TEMPERATURE DIFFERENCE

    • D. 

      SHOW THE LEAST BENEFIT FOR DESCALING THE TUBES AT HIGH WATER VELOCITIES

  • 61. 
    GIVEN A REFRIGERATION SYSTEM WHICH INCLUDES A FORCED DRAFT COOLING TOWER, AN ECONOMIZER AND CHILLED WATER AS THE COOLING MEDIUM, THE HEAT THAT IS REMOVED FROM THE BUILDING IS FINALLY REJECTED:
    • A. 

      AS HEAT OF EVAPORATION OF THE COOLING TOWER

    • B. 

      IN THE ECONOMIZER

    • C. 

      IN THE EVAPORATOR

    • D. 

      CONDENSER WATER OUTLET

  • 62. 
    FROST APPEARING ON THE SUCTION LINE AND PART OF THE COMPRESSOR IS CAUSED BY?
    • A. 

      SLUGGING COMPRESSOR

    • B. 

      FLOODED EVAPORATOR

    • C. 

      STARVED EVAPORATOR

    • D. 

      UNINSULATED SUCTION LINE

  • 63. 
    EFFICIENCY OF THE REFRIGERATION CYCLE IS AFFECTED BY THE OPERATION OF THE CONDENSER.  OF THE FOLLOWING A MORE EFFICIENT OPERATION OF A CENTRIFUGAL COMPRESSOR RESULTS FROM:
    • A. 

      RAISE THE CONDENSER LIQUID LEVEL TO THE MAXIMUM

    • B. 

      PRODUCE A LARGE AMOUNT OF LIQUID SUB-COOLING

    • C. 

      RAISE THE CONDENSER HEAD PRESSURE

    • D. 

      LOWER THE CONDENSER PRESSURE

  • 64. 
    DURING A WALK THROUGH OF THE ENGINE ROOM THE RMO NOTICES EXCESSIVE SUPERHEAT AT THE EVAPORATOR OUTLET, THIS WOULD MOST LIKELY BE CAUSED BY:
    • A. 

      STARVED EVAPORATOR

    • B. 

      LEAK IN SYSTEM

    • C. 

      LOW REFRIGERANT CHARGE

    • D. 

      ANY OF THE ABOVE

  • 65. 
    DURING A PARTICULAR ROUND AN OPERATOR NOTICES THAT THE SUCTION LINE AND PART OF THE COMPRESSOR ARE FROSTED, THE MOST LIKELY CAUSE OF THE CONDITION IS
    • A. 

      NOT ENOUGH REFRIGERANT IN SYSTEM

    • B. 

      EXPANSION VALVE OPEN TOO WIDE

    • C. 

      THE COMPRESSOR IS RUNNING CONTINUALLY

    • D. 

      COMPRESSOR VALVES ARE LEAKING

  • 66. 
    DUE TO A COLD FRONT, THERE WAS A SHARP DROP IN O.A.T., THE MOST LIKELY EFFECT OF THIS CONDITION ON THE OPERATION OF THE RECIPROCATING MACHINE WOULD BE THAT THE THERMOSTAT CAUSES SOLENOID VALVE TO:
    • A. 

      CLOSE, THE COMPRESSOR PUMPS DOWN AND SHUTS DOWN ON LOW PRESSURE

    • B. 

      CLOSE AND THE COMPRESSOR WILL START ON HIGH PRESSURE

    • C. 

      OPEN AND COMPRESSOR WILL PUMP DOWN AND GO OFF ON HIGH PRESSURE

    • D. 

      OPEN AND COMPRESSOR WILL CONTINUE TO RUN AT REDUCED SPEED

  • 67. 
    CONVERT 18" VACUUM TO PSIA
    • A. 

      7.7

    • B. 

      0.6

    • C. 

      5.9

    • D. 

      23.5

  • 68. 
    AT THE PLANT WHERE YOU ARE EMPLOYED A REFRIGERATING UNIT IS BEING TAKEN OUT OF SERVICE FOR MAJOR REPAIRS AND THAT YOU HAVE BEEN ASSIGNED TO WITHDRAW REFRIGERANT FOR STORAGE IN A 40 GALLON CONTAINER.  ACCORDING TO THE NYC FIRE HANDBOOK, THE MAXIMUM QUANTITY OF REFRIGERANT IN GALLONS THAT YOU MAY LEGALLY FILL EACH CONTAINER WITH UNDER ANY CIRCUMSTANCES IS:
    • A. 

      36

    • B. 

      30

    • C. 

      24

    • D. 

      32

  • 69. 
    AT THE CONDENSER, REFRIGERANT ENTERS AS
    • A. 

      HIGH PRESSURE GAS AND LEAVES AS LOW PRESSURE LIQUID

    • B. 

      HIGH PRESSURE GAS AND LEAVES AS HIGH PRESSURE LIQUID

    • C. 

      SUPERHEATED GAS AND LEAVES AS HIGH TEMPERATURE LIQUID

    • D. 

      HIGH TEMPERATURE GAS AND LEAVES AS SUPERHEATED GAS

  • 70. 
    ASSUMING ALL CONIDITIONS ARE REMAIN CONSTANT, THE HP PER TON OF REFRIGERATING EFFECT WOULD MOST LIKELY BE
    • A. 

      DECREASE AS THE SUCTION PRESSURE INCREASES

    • B. 

      INCREASE AS AS THE SUCTION PRESSURE INCREASES

    • C. 

      DECREASE AS THE DISCHARGE PRESSURE DECREASES

    • D. 

      INCREASE AS THE DISCHARGE PRESSURE INCREASES

  • 71. 
    ASSUME THAT THE OPERATOR HAS A CHOICE OF 4 VALVES TO SELECT FROM AND WANTS TO MINIMIZE PRESSURE DROP.  OF THE FOLLOWING THE OPERATOR SHOULD AVOID THE USE OF:
    • A. 

      BALL

    • B. 

      PLUG

    • C. 

      GLOBE

    • D. 

      GATE

  • 72. 
    ASSUME AN OPERATOR IS ABLE TO OBSERVE R-11, WATER AND LUBRICATING OIL TOGETHER AT 70°F.  UNDER THESE CONDITIONS, THE WATER, MOISTURE, AND FLUIDS WOULD SETTLE IN THE CONTAINER FROM TOP TO BOTTOM IN WHAT ORDER?
    • A. 

      WATER, OIL, REFRIGERANT

    • B. 

      OIL, REFRIGERANT, WATER

    • C. 

      REFRIGERANT, OIL, WATER

    • D. 

      OIL, WATER, REFRIGERANT

  • 73. 
    • A. 

      1000 POUNDS

    • B. 

      100 POUNDS

    • C. 

      200 POUNDS

    • D. 

      300 POUNDS

  • 74. 
    AS AN RMO IN CHARGE, YOU ARE REQUESTED TO REPLACE THE GAUGE ON THE HIGH SIDE OF THE REFRIGERATION SYSTEM.  THE PRESSURE GRADUATION RATE SHOULD BE
    • A. 

      1.2 OF DESIGN PRESSURE (AT LEAST)

    • B. 

      THE RUPTURE GUARD HAS TO BE REPLACED ALSO

    • C. 

      THE GAUGE HAS TO BE A COMPOUND GAUGE

    • D. 

      THE GAUGE SHOULD BE GRADUATED TO PRESSURE

  • 75. 
    AN RMO OBSERVES A GAUGE THAT READS THE SATURATION PRESSURE OF A REFRIGERANT.  IF CHILLED WATER IS BEING CIRCULATED AS THE COOLING MEDIUM, THIS READING CAN BEST BE USED TO ESTIMATE THE:
    • A. 

      CHILLED WATER TEMPERATURE RETURNING FROM THE BUILDING SPACES BEING COOLED

    • B. 

      TEMPERATURE OF THE CHILLED WATER BEING PUMPED TO THE BUILDING SPACES THAT ARE BEING COOLED

    • C. 

      PRESSURE OF CHILLED WATER BEING PUMPED TO THE BUILDING SPACES THAT ARE BEING COOLED

    • D. 

      COOLING TOWER EFFICIENCY

  • 76. 
    AN RMO NOTICES A KNOCKING RECIPROCATING COMPRESSOR.  THE RMO IS ASSURED THE COMPRESSOR HAS NO WORN PARTS.  THE MOST PROBABLE CAUSE OF THE KNOCKING IS:
    • A. 

      INADEQUATE LUBRICATION

    • B. 

      LIQUID SLUGGING

    • C. 

      CRANKCASE PRESSURE TO LOW

    • D. 

      SUCTION AND DISCHARGE NOT OPENING AND CLOSING

  • 77. 
    AN OPERATOR IS USING A SLING PSYCHROMETER TO MEASURE DRY AND WET BULB TEMP ON A ROOF OF A BUILDING WHERE THE COOLING TOWER IS LOCATED.  IF DURING THE DAY THE TEMP REMAINS CONSTANT, AND WET BULB DROPS BY 5°F, AND ALL OTHER CONDITIONS REMAIN UNCHANGED, THE OPERATOR SHOULD SEE:
    • A. 

      HIGH COOLING WATER BEING RETURNED

    • B. 

      RISE IN CONDENSER HEAD PRESSURE

    • C. 

      LOWER COOLING WATER TEMPERATURE RETURN

    • D. 

      NO NOTICEABLE EFFECT OF THE COOLING TOWER TEMP BEING RETURNED

  • 78. 
    AN OPERATOR IS USING A PORTABLE RECOVERY VESSEL AND COMPRESSOR TO RECOVER VAPOR REFRIGERANT FROM A MACHINE.  THE RECOVERY PROCESS WILL SLOW DOWN BECAUSE:
    • A. 

      COMPRESSOR CAPACITY WILL DECREASE

    • B. 

      VAPOR DENSITY WILL INCREASE

    • C. 

      THE REFRIGERANT TEMPERATURE WILL INCREASE

    • D. 

      THE REFRIGERANT PRESSURE WILL DECREASE

  • 79. 
    AN OPERATOR IS RUNNING TWO CENTRIFUGAL CONDENSER PUMPS IN PARALLEL, ONE OF THE PUMPS IS AT MAXIMUM PUMPING RATE, IF THE OPERATOR THROTTLES BACK ON THE DISCHARGE VALVE OF THE OTHER PUMP, THE MOST LIKELY EFFECT WOULD BE
    • A. 

      A REDUCTION ON BOTH THE WATER FLOW RATE AND PRESSURE INTO THE CONDENSER

    • B. 

      A REDUCTION IN TOTAL FLOW RATE TO CONDENSER

    • C. 

      A REDUCTION IN WATER PRESSURE AT THE CONDENSER INLET

    • D. 

      FOR THE PUMPS TO COMPENSATE TO MAINTAIN BOTH THE FLOW RATE AND DISCHARGE PRESSURE

  • 80. 
    AN OPERATOR HAS BEEN ASSIGNED TO RUN  A RECIPROCATING COMPRESSOR.  THE FOLLOWING ACTION CAPACITY CONTROL WOULD MOST LIKELY BE ACHIEVED THROUGH:
    • A. 

      OPENING THE SUCTION VALVES WITH SOME FORM OF CONTROL

    • B. 

      CONTROLLING THE DISCHARGE PRESSURE

    • C. 

      CHANGING THE STROKE AND ADDING RE-EXPANSION VOLUME

    • D. 

      RETURNING THE DISCHARGE GAS TO SUCTION

  • 81. 
    AN OPERATOR HAS BEEN ASSIGNED TO RUN A CENTRIFUGAL COMPRESSOR.  OF THE FOLLOWING ACTIONS A CAPACITY CONTROL IS MOST LIKELY TO ACHIEVE IS THROUGH
    • A. 

      BYPASS DISCHARGE GAS

    • B. 

      ADJUSTMENT OF THE IMPELLER INLET GUIDE PRE-ROTATION VANES

    • C. 

      CONDENSER PRESSURE VARIATION

    • D. 

      ADDING RE-EXPANSION VOLUME

  • 82. 
    AN OPERATOR HAS BEEN ASSIGNED TO A LARGE RECIPROCATING MACHINE WITHOUT UNLOADERS OF THE FOLLOWING SAFETY PROPER PROCEDURE FOR STARTING MACHINE IS. 
    • A. 

      FILTER SUCTION AND DISCHARGE VALVES

    • B. 

      SUCTION VALVE AND DISCHARGE BYPASS BOTH OPEN

    • C. 

      SUCTION BYPASS AND DISCHARGE VALVE BOTH OPEN

    • D. 

      DISCHARGE BYPASS AND SUCTION VALVE BOTH CLOSED

  • 83. 
    AN INLINE REFRIGERANT CLEANING SYSTEM IS ADVISABLE BECAUSE:
    • A. 

      NON-CONDENSEABLES CANNOT BE PROPERLY PURGED

    • B. 

      REFRIGERANT REACTS WITH THE LUBRICATION OIL

    • C. 

      REFRIGERANT SYSTEM IS HIGH PRESSURE

    • D. 

      REFRIGERANT IS A TOXIC CLASS

  • 84. 
    AN AUTOMATIC PURGE UNIT IS REQUIRED FOR THOSE REFRIGERATING SYSTEMS THAT HAVE
    • A. 

      DOUBLE INDIRECT OPEN SPACE SYSTEMS

    • B. 

      SYSTEMS OPERATING BELOW ATMOSPHERIC PRESSURE

    • C. 

      ABSORPTION COMPRESSORS

    • D. 

      OUTSIDE AIR DAMPERS

  • 85. 
    ACCORDING TO THE SAFETY HAND BOOK, HOW MUCH REFRIGERANT CAN BE RECOVERED INTO A 60 LB CONTAINER?
    • A. 

      60 LBS

    • B. 

      45 LBS

    • C. 

      30 LBS

    • D. 

      15 LBS

  • 86. 
    ACCORDING TO NYC FIRE CODE CLASSIFICATION OF REFRIGERANT, AMMONIA WOULD FALL UNDER WHICH GROUP?
    • A. 

      GROUP 1

    • B. 

      GROUP 2

    • C. 

      GROUP 3

    • D. 

      GROUP 4

  • 87. 
    A VERTICAL 12" WATER PIPE FROM THE ROOF HAS A PRESSURE GAUGE READING OF 120 PSI.  HOW TALL IS THE PIPE?
    • A. 

      277 FEET

    • B. 

      1,440 INCHES

    • C. 

      1,440 FEET

    • D. 

      277 INCHES

  • 88. 
    A RUPTURE DISC IN A CENTRIFUGAL REFRIGERATING MACHINE IS NORMALLY LOCATED ON THE
    • A. 

      CONDENSER

    • B. 

      ECONOMIZER

    • C. 

      COMPRESSOR DISCHARGE

    • D. 

      EVAPORATOR

  • 89. 
    A ROOM THERMOSTAT CONTROLS THE LIQUID LINE SOLENOID VALVE IN THIS COMMERCIAL REFRIGERATION SYSTEM.  THE COMPRESSOR IS ACTIVATED BY:
    • A. 

      THE HIGH PRESSURE CUT IN

    • B. 

      THE LOW SIDE PRESSURE STAT

    • C. 

      THE THERMOSTATIC EXPANSION VALVE

    • D. 

      THE THERMOSTAT THAT ACTIVATES THE SOLENOID VALVE

  • 90. 
    A RMO WOULD EXPECT A RELIEF VALVE TO START FUNCTIONING (FOR THE SECTION OF REFRIGERATING SYSTEM BEING PROTECTED) AT A PRESSURE MOST CLOSEST TO:
    • A. 

      5% OVER DESIGN PRESSURE

    • B. 

      THE DESIGN PRESSURE

    • C. 

      RECOMMENDED OPERATING PRESSURE FOR NORMAL COOLING CONDITIONS

    • D. 

      20% BELOW DESIGN PRESSURE

  • 91. 
    A RMO WAS INSTRUCTED TO CHARGE A 60 TON PLANT WITH R-134A REFRIGERANT.  THE OPERATOR WOULD MOST LIKELY FIND THE CHARGING VALVE ON THE:
    • A. 

      HIGH PRESSURE SIDE OF THE EQUIPMENT

    • B. 

      LOW PRESSURE SIDE OF THE EQUIPMENT

    • C. 

      DISCHARGE SIDE OF THE EQUIPMENT

    • D. 

      RECIEVER

  • 92. 
    A RMO NEEDED TO VARY THE FLOW OF REFRIGERANT IN A SYSTEM.  A CONTINUOUS VARIATION IN THE FLOW OF THE SYSTEM DOES NOT INCLUDE THE:
    • A. 

      SOLENOID VALVE

    • B. 

      HIGH SIDE FLOAT

    • C. 

      THERMAL EXPANSION VALVE

    • D. 

      CAPILLARY TUBE

  • 93. 
    A RECIPROCATING REFRIGERATION COMPRESSOR CYLINDER HAS A 12" BORE AND 16" STROKE, THE VOLUME OF REFRIGERANT IN CUBIC INCHES WOULD BE CLOSER TO
    • A. 

      1204

    • B. 

      1002

    • C. 

      1808

    • D. 

      1406

  • 94. 
    A PUMP AFFECTS THE PRESSURE OF A FLUID OR GAS BY: 
    • A. 

      REDUCING PRESSURE

    • B. 

      RAISING PRESSURE

    • C. 

      REGULATING PRESSURE

    • D. 

      STABILIZING PRESSURE

  • 95. 
    A PRESSURE RELIEF VALVE THAT IS INSTALLED ON A RECIPROCATING COMPRESSOR USING R-12 IS NORMALLY SET:
    • A. 

      ACCORDING TO DESIGN PRESSURE

    • B. 

      ACCORDING TO OPERATING PRESSURE

    • C. 

      LOWER THAN THE HIGH PRESSURE CUT OUT

    • D. 

      AT LOW PRESSURE CUT OUT PLUS 50%

  • 96. 
    A MOTOR HAS 4 BELTS, THE CENTER BELT IS WORN, YOU WOULD
    • A. 

      CHANGE THE CENTER BELT

    • B. 

      CHANGE CENTER BELT AND ALL OTHER BELTS

    • C. 

      CHANGE THE OTHER BELTS

    • D. 

      CHANGE TO DIRECT DRIVE SYSTEM

  • 97. 
    A JET EJECTOR IS USED TO RAISE OIL MIXED WITH REFRIGERANT WHICH HAS COLLECTED AT THE BOTTOM OF THE EVAPORATOR.  IF RESTRICTED
    • A. 

      THE FLOW OF OIL WILL NOT BE EFFECTED

    • B. 

      YOU WILL HAVE INSUFFICIENT HEAD TO LIFT THE OIL

    • C. 

      THE TEMPERATURE OF THE REFRIGERANT EXITING THE JETS WILL DECREASE

    • D. 

      THE OIL IN THE BOTTOM OF THE CHILLER WILL NOT LIFT IF IT BECOMES MIXED WITH LESS REFRIGERANT

  • 98. 
    A CONSTANT PRESSURE EXPANSION VALVE IS BEING USED INSTEAD OF A THERMOSTATIC EXPANSION VALVE UNDER VARIOUS LOADS WILL:
    • A. 

      STARVE THE EVAPORATOR

    • B. 

      FLOOD THE EVAPORATOR

    • C. 

      OPERATE BETTER THAN TEV

    • D. 

      BOTH A AND B ARE CORRECT

  • 99. 
    A BIMETAL DISK OR KLIXON IS USED TO
    • A. 

      STOP THE REFRIGERATION EQUIPMENT BEFORE EXCESSIVE PRESSURE OCCUR

    • B. 

      STOP THE REFRIGERATION EQUIPMENT AT A PREDETERMINED MINIMUM OPERATING PRESSURE

    • C. 

      PROTECT THE WIRING AND COMPONENTS AGAINST EXCESSIVE CURRENT DRAW

    • D. 

      PROTECT THE COMPRESSOR AGAINST THE LOSS OF OIL PRESSURE

  • 100. 
    1000 BTU'S ARE REMOVED FROM 100 POUNDS OF WATER AT A TEMPERATURE OF 55°F.  WHAT IS THE FINAL WATER TEMPERATURE?
    • A. 

      55°F

    • B. 

      50°F

    • C. 

      45°F

    • D. 

      40°F