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10 Cards in this Set
- Front
- Back
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When using lighted sulphur candles to test for ammonia leaks in a refrigeration system, the presence of ammonia will be indicated by a) a cloud of yellow smoke b) light brown smoke c) heavy white smoke d) heavy black smoke e) light red smoke |
c) heavy white smoke |
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Charging a refrigeration syste a) is done with the expansion valve closed b) is done by adding refrigerant between the liquid shutoff valve and the expansion valve c) is done with the compressor shut down d) is done between the condenser and the receiver e) is done between the suction valve and teh compressor |
b) is done by adding refrigerant between the liquid shutoff valve and the expansion valve |
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Which of the following is not a recommended step for the procedure in which dry nitrogen is used for a system leak test? a) remove controls and reief valves which may be damaged by the test pressure b) connect the nitrogen cylinder to the system charging valve c) open the liquid shut off valve d) open the compressor suction valve e) set the pressure reducing valve for the minimum design pressure of the high side |
d) open the compressor suction valve |
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The initial refrigerant charge is given where on the system? a) the high side of the system b) the low side of the system c) the evaporator d) the expansion valve e) the heat exchanger |
a) the high side of the system |
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What statement is false? a) to add refrigerant to a refrigeration system, we may use scale for its weight measurement b) overcharging a system may cause problems c) non-condensable gases may cause high head pressures d) high side pressure is always higher than the low side pressure e) non-condensable gasses need to be purged from the top of the evaporator and the bottom of the condenser |
e) non-condensable gasses need to be purged from the top of the evaporator and the bottom of the condenser |
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The liquid line shut off valve is a) used when purging the system b) a regulating valve c) used to relieve pressure d) required to be closed when charging the system e) on top of the receiver |
d) required to be closed when charging the system |
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When initially charging a refrigeration system a) it must be done with liquid line shutoff valve open b) it is done with a liquid refrigerant c) must be done after the unit is shut down d) must be done at the compressor suction e) water should be added to dilute the refrigerant |
b) it is done with a liquid refrigerant |
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Frost formation on the suction line of a refrigeration system indicates what? a) moisture in the system b) copper-plating on the bearings and compressor exhaust valve c) overcharging the system d) thermostat controlled solenoid deterioration e) inadequate levels of refrigerant in the system |
c) overcharging the system |
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High head pressure in a refrigeration system usually indicates a) broken plates in the compressor discharge valves b) air or non-condensable gases in the system c) broken plates in the compressor suction valves d) lack of refrigerant in the syste e) the cooling water temperature is too low |
b) air or non-condensable gases in the system |
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When draining excess oil from the compressors crankcase, by opening the oil drain valve or removing the drain plug, caution should be exercised for which of the following reason? a) the oil is very hot b) the oil is very cold c) residual pressure in the crankcase may blow refrigerant vapour and oil out d) old oil is contaminated with refrigerant and may be very acidic e) oil can never be drained below the critical minimum level |
c) residual pressure in the crankcase may blow refrigerant vapour and oil out |
