- Study guides, Class notes & Summaries

What concentration is R-717 refrigerant toxic at? - Answer-0.03% by volume in air. What is the toxic level of refrigerant R0123? - Answer-In concentrations over 0.1% by volume in air. What is R-290 (Propane) explosive range - Answer-Between 2.1% and 9.5% What is the explosive range for R-717? - Answer-Between 15-28%. Propane is more flammable and explosive than ammonia. Why is it best to measure ammonia at different heights? - Answer-Because it is lighter than air. When is a refri...

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5 pages

Written in 2024/2025

Grade A+

lectknancy

Section _____ , National Recycling and Emissions Reduction Program, of the Clean Air Act of 1990 requires management of refrigerants and refrigeration systems to maximize recovery and recycling of ozone-depleting substances during the servicing and disposal of air conditioning and refrigeration equip-ment. - Answer-608 What does EPA stand for? - Answer-Environmental Protection Agency The EPA is responsible for establishing and enforcing Section 608, which was created for the protection of ...

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7 pages

Written in 2024/2025

Grade A+

lectknancy

efficiency of the refrigerant cycle is affected by the operations of the condenser. Of the following, a more efficient centrifugal compressor operation results from: - Answer-Lowering the condensing pressure The heat removed from the refrigerant in a condenser is: - Answer-sensible and latent heat The refrigerant unit that you have been assigned to is being taken out of service for a major repair. You have been assigned to withdraw refrigerant for storage in suitable containers. According ...

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16 pages

Written in 2024/2025

Grade A+

lectknancy

What is refrigeration - Answer-Refrigeration is the removing of heat from an object or mass and then dissipating that same heat in a place where it's presence will not be objectionable. "Refrigeration systems move heat" The refrigeration process is made possible by - Answer-Boiling a refrigerant BTU "British Thermal Unit" - Answer-A BTU is the quantity of heat needed to raise one pound of water one degree Fahrenheit. Specific Heat - Answer-The specific heat of a substance is the nu...

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36 pages

Written in 2024/2025

Grade A+

lectknancy

What may be the cause of compressor knocking? - Answer-Liquid refrigerant slugging in the compressor. What will happen if the Spring on the TEV was to break ? - Answer-Flood the evaporator and raise suction pressure. What happens in the TEV equalizer line when pressure drops in the evaporator ? - Answer-The TEV equalizer compensates for the loss in pressure. What is the function of the Service Valve Stem Cap ? - Answer-To protect the valve from leaking the refrigerant. What is the pr...

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3 pages

Written in 2024/2025

Grade A+

lectknancy

Which is not a basic component of the compression refrigeration cycle? - Answer-D) Suction Filter pg 509 Describe modulating fluid flow - Answer-Modulating fluid flow is throttling the amount of fluid through a gas line. Controlling the flow between maximum or no flow. pg 510 The purpose of the crankcase pressure-regulating valve is to - Answer-D) prevent a compressor overload condition pg 513 Describe the function of the electric evaporator pressure-regulating valve (EEPR) - Answer-The...

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3 pages

Written in 2024/2025

Grade A+

lectknancy

true - Answer-one-trip refrigerant cylinders cannot be refilled under any circumstances true - Answer-if a recovery tank is empty and at atmospheric pressure, it is recommended that the tank be turned upside down with the vapor valve open false - Answer-cylinders of compressed gasses shall be transported in a horizontal position, unless packed in boxes or crates of such size as to prevent their overturning, or unless loaded into suitably secured racks, or otherwise secured in an upright po...

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4 pages

Written in 2024/2025

Grade A+

lectknancy

Name the 4 steps of a mechanical refrigeration system - Answer-evaporation, expansion, compression, & condensation Name the 4 parts of a refrigeration system - Answer-compressor, condenser, receiver, & evaporator Name the 3 methods of heat transfer - Answer-conduction, convection, & radiation What type of heat increases temp, but the state remains the same? - Answer-sensible heat 600,000 BTU/HR = ____ tons of refrigeration? - Answer-50 How many tons of refrigerant is req'd to pre...

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4 pages

Written in 2024/2025

Grade A+

lectknancy

58-Cooling tower water requires the addition of chemical additives in order to. - Answer-Reduce the formation of scale and algae 59-In the picture below describe equipment function - Answer-Remove non condensables from condenser 60-The Viscosity of lubrication oil is described by a number. A low viscosity number describes an oil that - Answer-Flows easily 61- The most likely reason for a refrigeration engineer to use a psychomotor is to measure - Answer-Relative humidity level of the at...

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4 pages

Written in 2024/2025

Grade A+

lectknancy

132-picture of pump - Answer-90* reducing elbow, pump suction, pump casing, pump discharge, check valve. 133-picture of a compressor - Answer-Oil charging port allows for the addition and removal of oil from the compressor 134- A facility has failed to maintain water treatment to a refrigeration system. - Answer-Increase the condenser pressure 135-Which of these compressors is a non positive displacement type of compressor - Answer-Centrifugal 136-Where is emergency power not require...

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3 pages

Written in 2024/2025

Grade A+

lectknancy

When the pressure difference across a capillary tube is increased: a. The flow of refrigerant increases. b. The flow of refrigerant decreases. c. The pressure of the refrigerant increases. d. The pressure of the refrigerant decreases. e. There is no change in the flow rate. - Answer-a The king valve on an ammonia vapor compression system serves as a: a. Refrigerant control valve. b. Valve to connect the ammonia drum when charging the system. c. Brine control valve. d. Master isolati...

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12 pages

Written in 2024/2025

Grade A+

lectknancy

Of The Following Characteristics Of Refrigerant&Comma; The One That Best Describes Refrigerant 22 Is∷ - Answer-Odorless When Mixed With Air &Newline; &Newline;Because Of The Latent Heat Load&Comma; Refrigeration Machine Operator Was Instructed To Start The Reciprocating Plant For Air Conditioning&Period; Of The Following According To Recommended Practice&Comma; The First Thing To Do Is - Answer-Turn On Chilled Water Pump&Comma; Condenser Water Pumps And Cooling Tower Fans &Newline; &Newline;The Most Important Reason To Use 2 Compressors In A Cascade System &Period;&Period;&Period;

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9 pages

Written in 2024/2025

Grade A+

lectknancy

What is a jurisdiction? - Answer-Each province and territory is its own jurisdiction Explain the intent of the regulation's governing the operation of boilers and pressure equipment? - Answer-To give the director or administrator of the department or branch or government a means of evolving, within the framework of the intent of the act, to meet changes in technology, concept, and the use of those variables listed within the scope of the act. Is it more difficult to change an act or a reg...

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27 pages

Written in 2024/2025

Grade A+

lectknancy

Which of the following is used for piping natural gas? - Answer-Black iron What material is used for refrigerant piping, heating, AC, and refrigeration? - Answer-Copper tubing What material is most commonly used today for cold water piping in houses? - Answer-P VC What material is used for natural gas piping? - Answer-Iron pipe List the pipe and tubing used HVACR - Answer-Copper, aluminum, steel, PVC, CP VC Which of the following will occur is copper is bent? - Answer-It will hard...

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16 pages

Written in 2024/2025

Grade A+

lectknancy

What refrigeration systems are most likely to leak refrigerant in building spaces that are being cooled? - Answer-Direct systems An operator has been assigned to a large reciprocating machine without Unloaders of the following safety proper procedure for starting this machine is?5 - Answer-Suction valve and discharge bypass both open Upon being Assigned to a facility during inspection of the facility you find there has been failure to maintain water treatment inspecting the condenser water...

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20 pages

Written in 2024/2025

Grade A+

lectknancy

refrigeration - Answer-A branch of science that deals with process of cooling of a space or substance below the environmental temperature. refrigeration system - Answer-An assembly of four major components, namely the compressor, condenser, expansion valve, evaporator through which a very low boiling point substance flow in a cycle and absorbs heat from the immediate surroundings, thereby producing the cooling effect. refrigeration cycle - Answer-A sequence of thermodynamic processes where...

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6 pages

Written in 2024/2025

Grade A+

lectknancy

To temperature operation of a refrigeration system is necessary win - Answer-More than one evaporator is used with one compressor Which of the following is another type of low ambient temperature head pressure control - Answer-Air volume control using shutters in fan cycling ____ are snap acting valves that open and close very fast with electrical energy to the coil - Answer-Solenoid valves The heat reclaim valve is a three way valve that is ____ operated - Answer-Pilot ______Type wa...

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2 pages

Written in 2024/2025

Grade A+

lectknancy

A hot pull down occurs when: a) there is excessive ice on the evaporator b) the condenser has been flooded c) the metering device is starving the evaporator d) the temperature of the load is high and the compressor has to run for long periods of time to lower the load d) all of the above - Answer-d) The receiver is located in the: - Answer-Liquid line The solenoid valve is used to control fluid flow. This valve: a) has a slow reaction time b) has a fast or snap action c) is used to...

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20 pages

Written in 2024/2025

Grade A+

lectknancy

What is the normal box temp on a medium temp walk in refrigerator - Answer-35 to 37 degrees What is the temp for reach ins - Answer-38 to 40 degrees What is the temp on walk in Freezers - Answer--10 degrees What is the temp on a reach in Freezer - Answer-0 degrees What is the normal evaporator TD for a Reach in refrigerator or freezer - Answer-20 degrees. (40 box - 20 evap =20) What is the normal evap TD for a walk in refrigerator or Freezer - Answer-20 degrees (35 box - 25 evap =...

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7 pages

Written in 2024/2025

Grade A+

lectknancy

which of the following gases is used as the baseline measurement for global warming potential? - Answer-carbon dioxide how does the global warming potential of R-410A compare to carbon dioxide? - Answer-it is thousands of times greater how do the global warming potentials of isobutane (R-600a), propane (R-290_ and R-441A compare to the GWPs of HFC-134a, R-404A and R-410A? - Answer-they are significantly lower which of the following refrigerants is an HFO? - Answer-R-1234yf Which of t...

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4 pages

Written in 2024/2025

Grade A+

lectknancy