HVAC Excellence Electricity Exam Complete Questions And Correct Answers

HVAC Excellence Electricity Exam Complete Questions And Correct Answers Q.Heat which causes a change in temperature of a substance is called - ANSWERS-sensible heat, Q.Heat added to a substance without a rise in temperature; (example: liquid refrigerant to gas) this process la called? - ANSWERS-latent heat Q.Heat added to the refrigerant in vapor state after the evaporation process is called, - ANSWERS-superheat Q.A scroll compressor moves refrigerant by means of; - ANSWERS-involute spirals Q.The movement of heat by way of fluid or is called; air - ANSWERS-convection Q.The movement of heat through a solid object is called; - ANSWERS-radiation Q.The standard unit for measuring the quantity of heat in a substance is - ANSWERS-British Thermal Unit Q.A refrigerant gives up heat when it; - ANSWERS-it condenses Q.Why must refrigerant in the suction line be slightly warmer than the saturation temperature? - ANSWERS-prevent liquid slugging of the compressor. Q.It is desirable for refrigerant in the suction line to be slightly superheated in order to; - ANSWERS-insure liquid refrigerant does not enter the compressor., Q.The state of the refrigerant in the suction line should be - ANSWERS-low pressure/ low temperature vapor Q.The state of the refrigerant entering the condenser is - ANSWERS-High Pressure/ Highly Superheated Vapor Q.The Evaporator - ANSWERS-Transfers heat from the refrigerated space to the refrigerant Q.The Evaporator - ANSWERS-Transfers heat from the refrigerated space to the refrigerant Q.Which of the following is not a Thermodynamic Property of refrigerant - ANSWERS-Flammability Q.The sequential order of steps in the vapor-compression process are: - ANSWERS-Compression, Condensation, Expansion, Vaporization Q.If a 30 lb container of $-410A refrigerant has been stored over night at 70 degrees F, the pressure in the cylinder should be approximately - ANSWERS-201 Degrees Faranheit Q.Fan Airflow pressures are usually measured in - ANSWERS-Inches of water column Q.Zero Psia (pounds per square inch absolute) is - ANSWERS-a pressure which cannot be further reduced Q.Zero Psig (pounds per square inch gauge) - ANSWERS-The same as atmospheric pressure Q.The Temperature at which moisture will start to condense from the air is called - ANSWERS-Dew Point Temperature Q.A Compound pressure gauge measures - ANSWERS-Pressure and Vacuum Q.A Mechanical shaft seal is necesssary on a - ANSWERS-Open drive compressor Q.Liquid slugging is - ANSWERS-Liquid refrigerant in the compressor clearance space Q.The Clearance space in a reciprocating compressor - ANSWERS-has an effect on compressor capacity Q.Which of the following types of air conditioning compressors is more efficient - ANSWERS-Centrifugal Q.Which of the following represnet the right order for the functionsof a condenser - ANSWERS-De-Superheats, Condenses, and Sub-cools Q.Refrigerant R-134a vapor enters the condenser at 124psig, 100 degrees faranheit, It leaves as a liquid from the condenser, sub-cooled 20 degrees faranheit, and the pressure will be approximately - ANSWERS-124 psig