A cargo of refrigerated fruit is packed in crates with transverse members dividing the crate in two equal parts. Which statement is TRUE?（）

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• If the head pressure of a reciprocating refrigeration compressor is excessive, （）.

  A . the relief valve should open before the high pressure cutout B . the relief valve should open and allow the excess refrigerant to flow to the receiver C . the high pressure cutout switch should operate before the relief valve opens D . you should close in on the suction valve

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• The sudden reduction of pressure occurring within the crankcase of a refrigeration compressor during starting causes the （）.

  A . sudden evaporation of wax crystals in the lubricant B . sudden evaporation of entrapped air in the lubricant C . release of refrigerant from the oil/refrigerant mixture D . release of dissolved lubricant from the refrigerant

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• Foaming of the oil in a refrigeration compressor crankcase is caused by （）.

  A . refrigerant boiling out of solution from the lube oil B . liquid refrigerant flooding the compressor and system C . lube oil viscosity being reduced by refrigerant dilution D . compressor suction pressure suddenly increasing

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• When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should （）.

  A . increase the amount of cooling water to the condenser B . decrease the amount of cooling water to the condenser C . add more refrigerant to the system D . remove some refrigerant from the system

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• When fruit is carried as refrigerated cargo，the most frequent cause of its being infected at the discharge port is（）.

  A . leaks in the ship's refrigeration system B . improper cleaning of the cargo spaces C . carriage at the wrong temperature D . improper precooling of the cargo space

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• In the refrigeration system, a shortage of refrigerant is indicated by （）.

  A . the compressor short cycling on high pressure cut out switch B . high suction pressure C . high head pressure D . bubbles in the sight gla

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• What entry on a dangerous cargo manifest concerning the classification of a cargo is correct? （）

  A . Class 8 B . Class 3 - flammable liquid C . Division 2.2 - nonflammable gas D . All of the above are correct

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• One cause of high head pressure occurring in a refrigeration system can be （）.

  A . insufficient cooling water flow to the condenser B . a low refrigerant charge in the system C . the liquid valve is open too much D . high evaporator superheat

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• In a refrigeration system, the refrigerant absorbs the latent heat of vaporization in the（）.

  A . compressor B . condenser C . receiver D . evaporator

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• Should a person be overcome due to lack of oxygen and high concentration of refrigerant, treat with（）.

  A . fresh water B . fresh air C . salt water D . artificial respiratio

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• In a refrigeration system, foaming of the crankcase oil may cause the （）.

  A . expansion valve to overfeed B . compressor to knock C . water regulating valve to fail D . crankcase drains to plug

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• The effect of high vapor superheat in a refrigeration system, is a/an （）.

  A . increased capacity of the compressor B . more efficient operation of the thermal expansion valve C . decreased capacity of the compressor D . loss of receiver capacity

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• In preparing a cargo space for receipt of a shipment of bagged cargo，which instruction for laying dunnage should be followed? （）

  A . Use either 1 or 2 tiers of dunnage，spacing the pieces in each tier a foot apart，and lay pieces in the bottom tier diagonally to the ship's side B . Use 1 tier of dunnage，laying the pieces tightly together to form a solid floor over the steel deck C . Use 2 tiers of dunnage，spacing the pieces in the bottom tier about a foot apart and the pieces in the top tier 6 inches apart D . Use 2 tiers of dunnage，spacing the pieces in the bottom tier about a foot apart and the pieces in the top tier together

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• Refrigerant entering the compressor of a refrigeration system should be in which of the following conditions?（）

  A . Sub-cooled liquid B . Sub-cooled vapor C . Superheated vapor D . Liquid

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• The temperature of a refrigerant gas is the highest （）.

  A . at the compressor discharge B . at the compressor suction C . in the expansion valve D . in the receiver

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• For a given weight of cargo，the stress on the heel block of a cargo boom（）.

  A . increases as the cargo closes the head while hoisting B . increases if the cargo runner is doubled up C . decreases as the boom is topped to a greater angle D . is determined by the thrust stresses on the boom

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• The presence of bubbles in a refrigeration system liquid line may （）.

  A . promote refrigerant dehydration B . be absorbed in the receiver C . cause low condensing pressure D . carry moisture and lead to corrosio

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• The component of a refrigerating system in which the refrigerant vaporizes and absorbs heat is known as the （）.

  A . condenser B . vapor generator C . accumulator D . evaporator

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• In a compression refrigeration cycle, the temperature of the liquid refrigerant experiences its greatest decrease in the（）.

  A . evaporator B . compressor C . expansion valve D . condenser

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• Sub-cooling is a method of reducing the temperature of the liquid refrigerant below its （）.

  A . freezing point B . floc point C . condensing temperature D . compression temperature

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• In a chilled water air conditioning unit using a reciprocating compressor, the refrigerating effect of the primary refrigerant can be increased by （）.

  A . increasing refrigerant pressure in the coil B . increasing chilled water flow through the cooler C . sub-cooling the refrigerant in the condenser D . superheating the refrigerant in the compressor

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• The function of （） in a refrigeration plant using Freon is to move moisture from all refrigeration system.

  A . filter B . filter drier C . heat exchanger D . air cooler

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• A pressure drop in the liquid line of a refrigeration system may cause（）

  A . the solenoid valve to seize B . the compressor to hunt C . flash gas to form in the liquid line D . the expansion valve to freeze ope

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• Excessive circulation of the lubricating oil with the refrigerant in a refrigeration system will cause______.

  A.carbon deposits on the compressor suction valves B.the evaporator temperature to increase C.rapid corrosion of the thermal expansion valve D.no operating problems

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