Refrigerant Machine Operator Practice Test #3 Flashcards by Christine Banker

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

ON THE INLET LINE OF THE CONDENSER RECEIVER

How well did you know this?

Not at all

Perfectly

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

INCREASE SPEED OF MOTOR

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

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

TO CREATE PROPER EXHAUST VACUUM

How well did you know this?

Not at all

Perfectly

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

CLOSE WHEN THE LOAD INCREASES

How well did you know this?

Not at all

Perfectly

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

EVAPORATOR TEMPERATURE WILL GO DOWN

How well did you know this?

Not at all

Perfectly

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

180

2.31 feet of head to psi

How well did you know this?

Not at all

Perfectly

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

OHMS

VOLTAGE

AMPS

WATTS

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

How well did you know this?

Not at all

Perfectly

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

IN FRONT AND AFTER THE BULL’S EYE SIGHT GLASS

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

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

AMMETER ONLY READS AMPS

How well did you know this?

Not at all

Perfectly

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

GENERATOR AND RECTIFIER

ABSORBER AND EVAPORATOR

RECTIFIER AND CONDENSER

CONDENSER AND RECEIVER

GENERATOR AND RECTIFIER

How well did you know this?

Not at all

Perfectly

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?

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.

How well did you know this?

Not at all

Perfectly

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

VALVE PLATE BEING HELD DOWN BY A SPRING

How well did you know this?

Not at all

Perfectly

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

NON FLAMMABLE / NON TOXIC

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

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

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.

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

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

USE A LARGE RADIUS

How well did you know this?

Not at all

Perfectly

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

AT INLET OF EACH COMPRESSOR

How well did you know this?

Not at all

Perfectly

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

FAULTY (SUCTION) COMPRESSOR VALVE

How well did you know this?

Not at all

Perfectly

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

LESS THAN 5’

MORE THAN 5’

25’

50’

LESS THAN 5’

How well did you know this?

Not at all

Perfectly

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

THE PATH OF ELECTRICITY IN THE CIRCUIT

How well did you know this?

Not at all

Perfectly

HOW IS A WATTMETER USED? BY USING 4 LEADS, AND TAKING 1 READING BY TAKING 3 READINGS BY USING OHMMETER ALL OF THE ABOVE

BY USING 4 LEADS, AND TAKING 1 READING

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

SPRING PRESSURE

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

ADJUSTING THE SIZE OF THE VANE PASSAGES

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

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

IN GENERAL RETURNS THE OIL TO THE CRANKCASE

WHAT CONTROLS A SOLENOID VALVE ON MOTOR? WATTS VOLTS HORSE POWER AMPS

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.

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

AMOUNT OF REFRIGERANT IN THE MACHINE

HOW DOES A RECIPROCATING COMPRESSOR VARY CAPACITY? CYLINDER UNLOADERS HOT GAS BYPASS MOTOR SPEED VARIATIONS ALL OF THE ABOVE

ALL OF THE ABOVE

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

VARY THE PASSAGES OF THE VANES

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

To store the refrigerant after condensation

CONVERT 20 PSIG TO Hg ABSOLUTE 30 70 80 90

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

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

ACTUALLY LIFTS WATER TO THE PUMP SUCTION

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

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

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

50°F 500 BTU's of heat is equal to 10F. 500 btus removed is equal to 10 degrees removed

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

AMPERE

WHAT ARE THE RECOVERY REQUIREMENTS FOR LOW PRESSURE APPLIANCES 25" Hg 0 PSI 10" Hg 5" Hg

25" Hg

WHERE DO NON-CONDENSABLE VAPORS AND MOISTURE COLLECT? LIQUID LINE CONDENSER EVAPORATOR FILTER DRIER

CONDENSER

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

ALL OF THE ABOVE

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

OIL SUMP AND DRAIN FROM OIL VALVE

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

HOW MANY BTUs ARE ABSORBED IN 5 TONS OF ICE? 188,000 2,200,000 1,440,000 NONE

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

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

LOW VISCOSITY

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

SELF CONTAINED

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

OPEN A PLUNGER AND ALLOW REFRIGERANT IN

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

AMOUNT OF REFRIGERANT IN LARGEST MACHINE

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

TO OBTAIN LOW EVAPORATOR TEMPERATURES

WHICH IS BEST TO USE WHEN SOLDERING COPPER, IRON OR STEEL? BRAZING ALLOYS ANY LOW TEMPERATURE SOLDER 50-50 TIN LEAD SILVER SOLDER

SILVER SOLDER

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

EACH ONE FEEDS ITS OWN EVAPORATOR

WHAT IS THE PRESSURE OF R-22 AT 41°F? 38 PSIG 70 PSIG 18.5" Hg 81

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.

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

NEVER

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

FLOWS EASILY, SMOOTHLY

CENTRIFUGAL COMPRESSORS USE WHAT KIND OF REFRIGERANT? CFCs HIGH PRESSURE REFRIGERANT LOW PRESSURE REFRIGERANT ALL THE ABOVE

ALL THE ABOVE

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

FORM ACIDS AND SLUDGE

QUICK CONNECT FITTINGS ARE CONSIDERED AS: LOW LOSS FITTINGS SOLDERED FITTINGS FLARE FITTINGS AUTOMATIC LOSS FITTINGS

LOW LOSS FITTINGS

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

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

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.

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

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

BOTH A AND B ARE CORRECT

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

TRAVELS BACK TO THE OIL SUMP

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

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

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

STARTING UP

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

OPEN SUCTION SIDE VALVE AND PUT DISCHARGE IN THE THROTTLE POSITION

WHAT TYPE OF BEARING IS USED FOR TURBINE ROTOR SHAFT? NEEDLE BEARING SLEEVE BEARING BALL BEARING KINGSBURY BEARING

KINGSBURY BEARING

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

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

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

PREVENTS AIR FROM ENTERING WHEN IT IS UNDER NEGATIVE PRESSURE

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

SUCTION ON BOTTOM, DISCHARGE ON TOP

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

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

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

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

THE CENTER PORT OF THE GAUGE MANIFOLD IS CONNECTED TO? RECOVERY MACHINE CHARGING CYLINDER VACUUM PUMP ALL OF THE ABOVE

ALL OF THE ABOVE

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

15-20 MINUTES

WHEN A THERMOSTATIC EXPANSION VALVE IS OPERATING PROPERLY, THE END OF THE COIL WILL CONTAIN SATURATED VAPOR SUPERHEATED VAPOR LOW TEMPERATURE LIQUID HOT VAPOR

SUPERHEATED VAPOR

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

1°F

TO RAISE 10 LBS. OF WATER 1°F, HOW ANY BTUs DO YOU NEED? 1 5 20 10

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

LIQUID LEVEL GAUGES (EXCEPT BULL'S EYE TYPE) SHALL HAVE SHUT OFF VALVES: MANUAL ONLY AUTOMATIC ONLY VALVES NOT NEEDED MANUAL AND AUTOMATIC

MANUAL AND AUTOMATIC

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

VENT REFRIGERANT AND NITROGEN TO OPEN AIR

WHAT WOULD BEST DESCRIBE THE REFRIGERANT IN THE LAST EVAPORATOR COIL? VAPOR SATURATED VAPOR SUPERHEATED VAPOR DRY VAPOR

SUPERHEATED VAPOR

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

DRY VAPOR ABOVE ITS BOILING POINT

A RECIPROCATING COMPRESSOR SHAFT SEAL IS MADE UP OF: PLASTIC RUBBER GRAPHITE FIBER HEMP METAL

METAL

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

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

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

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

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

CAN'T TIGHTEN TO GET A GOOD SEAL

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

CARBON AND METAL

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

CAN VENT THE MIXTURE TO THE ATMOSPHERE

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

THE NEUTRAL LINE OF A 120/240 CIRCUIT

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

300 LBS

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

MELTING POINT OF ALLOY

WHEN WATER TURNS TO ICE, WHAT TAKES PLACE? SUPERHEAT HEAT OF FUSION HEAT OF EVAPORATION SUBCOOLING

HEAT OF FUSION

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

CAPACITOR

WHY IS GLYCOL A BETTER BRINE THAN SODIUM CHLORIDE? MORE CONDUCTIVE COST LESS NO CORROSION HIGHER FREEZING POINT

NO CORROSION

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

LOW PRESSURE CUT OUT, PRESSURE SWITCH

WHAT IS USED TO TRACK SPEED IN A STEAM TURBINE? TACHOMETER SPEEDOMETER PEDOMETER TRACKOMETER

TACHOMETER

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

SPRING TYPE TUBE BENDER

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

THREE WAY VALVE

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

CURRENT x VOLTAGE x POWER FACTOR

WHAT DOES A FILTER DRIER DO? REMOVES PARTICLES REMOVES MOISTURE REMOVES ACID ALL OF THE ABOVE

ALL OF THE ABOVE

A COMPRESSOR THAT USES A SHAFT WITH A MECHANICAL SEAL, WHAT IS THE VALVE PLATE MADE OF? METAL/CARBON PLASTIC RUBBER SILICON

METAL/CARBON

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

OXYGEN DEPRIVATION

Pass

Refrigerant Machine Operator Practice Test #3 Flashcards

(101 cards)