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UNIT 9 > UNIT 9 > Flashcards

UNIT 9 Flashcards

1
Q

Synthetic oil used with HCFC type refrigerants.

A

Alkylbenzene

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2
Q

Use of a recovery machine to recover refrigerant

A

Active recovery

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3
Q

Non-ozone depleting refrigerant, that do not contain chlorine or fluorine

A

Hydrocarbon

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4
Q

CONSIST OF THREE OXYGEN MOLECULES AND IS IN THE STRATOSPHERE

A

OZONE

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5
Q

WARMING PROCESS CAUSED BY THE ATMOSPHERE’S ABSORPTION OF HEAT ENERGY RADIATED FROM THE EARTH’S SURFACE.

A

GREENHOUSE EFFECT

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6
Q

USED MAINLY IN AUTOMOTIVE REFRIGERATION SYSTEMS. GLYCOLS BASED LUBRICANT ATTRACTS AND HOLDS MOISTURE READILY.

A

PAG OIL

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7
Q

A BLEND OF REFRIGERANTS THAT HAS MANY TEMPERATURES AS IT EVAPORATES AND CONDENSES.

A

TEMPERATURE GLIDE

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8
Q

BLEND OF TWO OR MORE REFRIGERANTS THAT BEHAVE LIKE A PURE REFRIGERANT

A

AZEOTROPE

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9
Q

USE OF SYSTEM COMPRESSOR OR INTERNAL PRESSURE TO RECOVER REFRIGERANT

A

PASSIVE RECOVERY

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10
Q

USED TO PREVENT THE LOSS OF REFRIGERANT FROM HOSES WHEN DISCONNECTING FROM A SYSTEM, RECOVERY/REFRIGERANT CYLINDER OR RECOVERY MACHINE.

A

LOW LOSS FITTINGS

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11
Q

MEETING THAT SET THE REDUCTION RATES FOR OZONE DEPLETING SUBSTANCES.

A

MONTREAL PROTOCOL

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12
Q

ESTER BASED LUBRICANT THAT ABSORBS MOISTURE READILY AND HOLDS IT MORE TIGHTLY. BEST IF STORED IN A METAL CONTAINER INSTEAD OF PLASTIC.

A

POE OIL

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13
Q

MOST REFRIGERANTS ARE

A

HEAVIER THAN AIR

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14
Q

WHICH OF THE FOLLOWING REFRIGERANTS IS VERY HIGH PRESSURE?

A

R-744

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15
Q

TRUE OR FALSE
WHEN A SYSTEM IS KNOWN TO HAVE A LARGE LEAK, RECOVER REFRIGERANT FROM THE SYSTEM UNTIL 0 PSIG IS REACHED TO PREVENT PULLING AIR AND NON CONDENSIBLE’S INTO THE SYSTEM AND INTO THE RECOVERY CYLINDER.

A

TRUE

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16
Q

TRUE OR FALSE
PASSIVE RECOVERY INVOLVES USING NON PRESSURIZED CONTAINER’S TO COLLECT THE REFRIGERANT FROM THE SYSTEM.

A

TRUE

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17
Q

TRUE OR FALSE
LIQUID DENSITY OF REFRIGERANT AT 77 DEGREES FAHRENHEIT MAY BE USED TO CALCULATE RECOVERY CYLINDER CAPACITY.

A

TRUE

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18
Q

TRUE OR FALSE
TO PREPARE A NEW RECOVERY CYLINDER TO ACCEPT REFRIGERANT, THE CYLINDER MUST BE PURGED OF NITROGEN AND EVACUATED A MINIMUM OF 5000 MICRONS.

A

FALSE

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19
Q

TRUE OR FALSE
NEVER DISCONNECT OR UNPLUG ANYTHING OR BEGIN A SERVICE PROCEDURE BEFORE CHECKING FOR FLAMMABLE REFRIGERANT IN THE AREA WITH A COMBUSTIBLE GAS LEAK DETECTOR OR MONITOR.

A

TRUE

20
Q

TRUE OR FALSE
THE LETTER “A” AT THE END OF “R-410A” SIGNIFIES THAT IT IS AN ISOMER OF R-410.

A

FALSE

21
Q

TRUE OR FALSE
THE LOWER EXPOSURE LIMIT (LEL) OF A GAS IS THE LOWEST CONCENTRATION OF THE GAS IN AIR CAPABLE OF PRODUCING A FLASH OR FIRE IN THE PRESENCE OF AN IGNITION SOURCE.

A

TRUE

22
Q

RETROFITTING OF A SYSTEM WITH AN HC OR OTHER FLAMMABLE REFRIGERANT IS ALLOWED IN THE UNITED STATES AS LONG AS PROPER SAFETY PRECAUTIONS ARE FOLLOWED.

A

FALSE

23
Q

TRUE OR FALSE
NEVER USE FUEL GRADE PROPANE IN A REFRIGERATION SYSTEM.

A

TRUE

24
Q

TRUE OR FALSE
CARBON DIOXIDE IS THE NUMBER ONE CONTRIBUTOR TO GLOBAL WARMING.

A

TRUE

25
Q

TRUE OR FALSE
TROPOSPHERIC OZONE IS CONSIDERED GOOD OZONE.

A

FALSE

26
Q

TRUE OR FALSE
THE HIGHER THE TEMPERATURE GLIDE, THE HIGHER THE FRACTIONATION POTENTIAL

A

TRUE

27
Q

MOST REFRIGERANTS ARE MADE OF ____________ AND _____________ MOLECULES.

A

METHANE AND ETHANE

28
Q

OZONE DEPLETION HAPPENS IN THE ______________. GLOBAL WARMING HAPPENS IN THE __________________.

A

STRATOSPHERE, TROPOSPHERE

29
Q

IT IS ILLEGAL TO VENT CFC AND HCFC REFRIGERANTS AS OF?

A

JULY 1, 1992

30
Q

WHAT TYPE OF REFRIGERANT IS CLASSIFIED AS “NATURAL REFRIGERANTS”?

A

HC

31
Q

WHAT IS THE VISUAL INDICATOR THAT A SYSTEM USES A FLAMMABLE REFRIGERANT?

A

LOOK AT THE DATA PLATE

32
Q

A RECOVERY CYLINDER LABELED FOR R-134a IS WEIGHED IN PREPARATION TO RECOVER R-134a FROM A SYSTEM. THE CYLINDER WEIGHS 31 POUNDS AND 13 OUNCES.
WHAT IS THE CYLINDER CAPACITY AND HOW MUCH MORE REFRIGERANT CAN BE ADDED TO THE CYLINDER?

A

0.764423077 X .8
= 0.611538462 X 67.46
= 41.25438465+26.9
= 68.154 38465 LBS = CYLINDER CAPACITY

ABOUT 37 MORE POUNDS CAN BE ADDED

33
Q

119 OZ - 2LBS 8 OZ=?

A

119 OZ - 40 OZ = 79 OZ = 4LBS 15 OZ

34
Q

12 LBS 5 OZ. - 2 LBS 8OZ.

A

197 OZ. - 40 OZ.= 157 OZ.= 9LBS 13 OZ.

35
Q

A RECOVERY CYLINDER OF R-410A WEIGHS 32 LBS. 3 OZ. TARE WEIGHT OF THE CYLINDER IS 26.9 LBS. HOW MANY POUNDS AND OUNCES OF REFRIGERANT IS IN THE CYLINDER?

A

5 LBS 4.6 oz

36
Q

DRAW A DIAGRAM OF A RECOVERY MACHINE HOOKED UP TO A SYSTEM USING A THREE-HOSE, TWO-VALVE MANIFOLD.
SHOW THE PLACE OF THE FILTER DRIER, RECOVERY CYLINDER AND SCALE USING THE APPION METHOD OF RECOVERY.

A

FIGURE 1.1 (YOUR DRAWING)

37
Q

YOU ARE RECOVERING REFRIGERANT BY LIQUID FIRST IN #36 ABOVE. YOUR MANIFOLD USES BALL VALVES ON THE END OF EACH HOSE. WHAT POSITION SHOULD THE COMPRESSOR SERVICE VALVES, MANIFOLD VALVES, BALL VALVES, RECOVERY MACHINE VALVES AND RECOVERY CYLINDER VALVES BE IN BEFORE STARTING THE RECOVERY MACHINE?

A
  1. MANIFOLD LOW SIDE GAUGE VALVE: BACKSEAT
  2. MANIFOLD HIGH SIDE GAUGE VALVE: BACKSEAT
  3. MANIFOLD SUCTION LINE (BLUE HOSE) BALLL VALVE: CLOSED
  4. COMPRESSOR SUCTION SERVICE PORT: MIDSEAT
  5. MANIFOLD DISCHARGE LINE (RED HOSE) BALL VALVE: OPEN
  6. COMPRESSOR DISCHARGE SERVICE PORT: MIDSEAT
  7. MANIFOLD RECOVERY HOSE (YELLOW HOSE) BALL VALVE: OPEN
  8. RECOVERY MACHINE INLET VALVE: OPEN
  9. RECOVERY MACHINE OUTLET VALVE: OPEN
  10. RECOVERY CYLINDER LOW SIDE (BLUE) VALVE: CLOSED
  11. RECOVERY CYLINDER HIGH SIDE (RED) VALVE: CLOSED
38
Q

YOU NEED TO RECOVER THE FULL CHARGE OF R-410A FROM A 3 TON CENTRAL AIR CONDITIONING SYSTEM.
THE FULL CHARGE ON THE DATA PLATE SHOWS THE UNIT IS CHARGED WITH 119 OZ.
YOU ARE GOING TO USE A NEW RECOVERY CYLINDER.
YOU PURGE THE NITROGEN OUT AND PULL A VACUMM DOWN TO 500 MICRONS.
WHAT IS THE MAXIMUM AMOUNT OF REFRIGERANT YOU CAN PUT IN THE RECOVERY CYLINDER?

A

INCORRECT DOT MARKING FOR USE

39
Q

WHAT IS THE PRESSURE ON THE LOW SIDE PRESSURE GAUGE IF THE EVAPORATOR TEMPERATURE IS -10 DEGREES FAHRENHEIT FOR A SYSTEM THAT USES R-410A?

A

36.4 PSIG

40
Q

HIGH SIDE PRESSURE GAUGE READS 114 PSIG. AT WHAT TEMPERATURE IS THE R-134a REFRIGERANT CHANGING BACK TO LIQUID INSIDE THE CONDENSER?

A

95 DEGREES FAHRENHEIT

41
Q

THE AMBIENT TEMPERATURE NEAR A STANDARD FIN AND TUBE CONDENSER IS 95 DEGREES FAHRENHEIT.
WHAT IS THE CONDENSING TEMPERATURE INSIDE THE CONDENSER?

A

95 + 30= 125 DEGREES FAHRENHEIT

42
Q

NEVER EXCEED THE DESIGN ________ SIDE FACTORY TEST PRESSURE ON THE NAME PLATE WHEN PRESSURIZING A SYSTEM WITH NITROGEN.

A

LOW

43
Q

WHEN CHANGING AN OUTDOOR CONDENSING UNIT FROM R-22 TO R-410A,
WHAT IS ONE PROBLEM THAT MAY OCCUR
IF THE EVAPORATOR ISNT CHANGED AT THE SAME TIME?

A

REFRIGERANT MAY NOT VAPORIZE FAST ENOUGH WHICH MAY LEAD TO LIQUID IN THE COMPRESSOR RESULTING IN POTENTIAL COMPRESSOR DAMAGE.

44
Q

WHAT TYPE OF REFRIGERANT BLEND IS A LONG-TERM REPLACEMENT FOR HCFC BLENDS?

A

HFC

45
Q

PRESSURE RELIEF VALVES SHOULD ALWAYS BE INSTALLED IN ___________ WITH ONE ANOTHER, NEVER IN SERIES.

A

PARALLEL

UNIT 9 (1 decks)

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