Tpc 432 Flashcards
As you increase the pressure in the container you also increase the boiling temperature also know as…
Saturation temperature
What is Enthalpy of saturated vapor?
It is the sum of Enthalpy of saturated liquid and the Enthalpy of evaporation
Compressor Horsepower formula
Heat flow rate = 432 ( 1/42.4 )
When a suction line heat exchanger is used to subcool the refrigerant liquid, where is the cold vapor pulled from?
It is from the evaporator
Condensate sub cooling happens between the receiver and the…
Expansion valve
The ideal refrigerate should not be…
Flammable
What is the purpose of classifying refrigerants with CFC, HCFC, and HFC?
Its groups refrigerants based on their chemical structure
What is an important term related to refrigerant blends?
Temperature glide
Refrigerant safety ratings go from A1 ( safest ) to…
B3 ( least safe )
What is something you must never do while working around/with refrigerant?
Never apply an open flame
What does the Ozone do?
It forms a protective shield that absorbs damaging ultraviolet radiation from the sun
Why are CFC’s Chlorofluorocarbons dangerous?
They absorb infrared radiation in the same way that carbon dioxide and methane do
Recycling involves the use of portable equipment, on site in order to…
Recover and clean refrigerant
Recycled refrigerant must be used on what system?
The same system that the refrigerant was pulled from originally
What is a method to reduce vibrations in the refrigeration system?
Mufflers installed in the discharge lines near the compressor will help to dissipate vibrations
All refrigeration and air conditioning service technicians must be certified to what class?
Class 1 and class 2 and it is a epa written exam
One of the main and final rules that the EPA enforces on the recycling and disposal of refrigeration is…
Reclaimer certification programs
What is active vs passive refrigerant recovery system?
Active has a self contained compressor, and passive utilizes upon the compressor of the refrigerant equipment
What certification is required for a technician to work on residential air conditioning?
Type II technician certification, ( high or very high pressure systems )
Does the EPA require equipment certification programs to maintain records?
Yes
What can filter-driers remove in refrigerant excluding moisture?
Filter-driers can also remove and neutralize acids in the system
What is the difference between absorption-type desiccant and adsorption-type desiccant?
Absorption- removes moisture by chemical action
Adsorption- removes moisture mechanically
If you place a filter-drier in a vertical position, where should the inlet be?
The inlet should be at the top and the outlet at the bottom so the refrigerant oil can not be trapped in the drier
What is a critical part when selecting filter driers?
Filtration capabilities, smallest particle it will filter and how often it needs replacing
What precautions should you observe when working with filter-driers?
Always wear safety goggles and gloves when working with refrigerants
What can you use to pressurize a system
To check for leaks before adding refrigerants?
Pressure the system with nitrogen and run a soapy solution over the suspected leak points
When installing gauges where do you install the high side line from the gauge manifold?
To the discharge service valve
What is a visual indication of there being low refrigerant levels in the system?
Vapor bubbles in the sight glass
How do you check to see if there is moisture in the system?
When the pressure in the system drops to 1000 microns, close the pump valve and stop the pump. If the vacuum gauge shows a rise in pressure there is moisture in the system
What is the best method for adding a complete charge to a system?
The weight method
What is miscibility?
Miscibility describes the ability of substances to mix, the miscibility of the oil and refrigerant is important at all temperatures
What problems can occur when oil mixes with refrigerant?
Clogging of desiccants
Where is an oil separator installed at?
This device is installed in the discharge line between the compressor and the condenser?
What problems can occur at low temperatures with moisture in a refrigerant system?
Moisture can freeze and block the flow of refrigerant
Should the compressor be running when you check the oil level in a refrigerant system?
No, it should be idle for at least ten minutes before you check the oil level
