Topics: All categories in the pool
1: How many refrigerant classifications are there for toxicity?
- 3
- 5
- 1
- 2
2: A hissing noise at the expansion valve is a good indication that
- expansion valve is oversized
- nothing is passing thru
- liquid is passing thru it
- gas is passing thru it
3: The purpose of an accumulator is to
- reduce friction loss to the flow of refrigerant
- store excess refrigerant from the reciver
- assure no liquid returns to the compressor
- filter out impurities from the system
4: In an A/C unit, dirty filters will cause
- high discharge pressure
- low oil pressure
- high suction pressur
- low suction pressure
5: What type of oil is used in R-410A systems?
- polyolester (POE)
- naphthene
- polyalkylene glycol (PAG)
- mineral oil
6: Pressure relief devices are marked with a ____________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
- UM or UL
- UV or UR
- UL and UM
- UL and UR
7: What device should be used on low-temperature freezers?
- hot-gas by-pass
- high capacity TXV
- discharge muffler
- oil separator
8: A room having machinery but no flame producing apparatus permanently installed and operated is considered a
- Class T machinery room
- Class A machinery room
- Class B machinery room
- Class M machinery room
9: A cross charged power element on an expansion valve would normally be used in what temperature range?
- 30F to 50F
- 0F-38F
- -40F to 0F
- -100F to -40F
10: The 4 basic methods of determining whether the proper amount of refrigerant is being introduced into the system are
- sight glass, weight, pressure, and dipstick
- sight glass, weight, pressure, and frost line
- sight glass, weight, paper method, and frost line.
- Buss-eye, weight, pressure, and frost line
11: The principle used in continuous type absorption systems is
- Boyle's Law
- Ohm's Law
- Dalton's Law
- Charles's Law
12: Instead of using a compressor, an absorption air-conditioning chiller uses which of the following as its driving force?
- Air
- Heat
- Electricity
- Oil
13: Dual-pressure relief devices should be installed on
- vessels of 3 cubic feet or less
- vessels of 10 cubic feet or more
- vessels of 10 cubic feet or less
- vessels of 3 cubic feet or more
14: A compressor in which the increase in vapor pressure is attained without changing the internal volume of the compression chamber is called
- neutral chamber-type compressor
- negative displacement compressor
- non-volumetric displacement compressor
- non-positive displacement compressor
15: What is the typical air conditioning operating pressures for R-22?
- 60 psi suction 210 psi discharge
- 25 psi suction 125 psi discharge
- 105 psi suction 340 psi discharge
- None of the above
16: Large mercantile occupancy is
- a premise or that portion of a premise where more than 1500 persons congregate on levels above or below street level to purchase personal merchandise
- a premise or that portion of a premise where more than 200 persons congregate on levels above or below street level to purchase personal merchandise
- a premise of that portion of a premise where more than 100 persons congregate on levels above of below street level to purchase personal merchandise.
- a premise of that portion of a premise where more than 50 persons congregate on levels above of below street level to purchase personal merchandise.
17: The best way to determine the voltage requirement for an electrical component is to
- check with the utility company
- read the voltage with a mulitmeter
- read the nameplate data
- determine the capacity of the service panel
18: Electricity involves the movement of electrons in atoms
- True
- False
19: Give an example of a secondary coolant?
- R-717
- R-12
- R-410A
- R-718
20: What is the purpose of a trap in a vertical discharge line with an upward flow?
- To insure proper oil return to the compressor
- Prevents oil from draining back to the compressor during the off cycle
- Both a & b
- None of the above
21: 1 HP = ____ Watts?
- 3,412
- 11,239
- 3.1416
- 746
22: R-410A is classified as a ____ refrigerant on the safety matrix.
- A-2
- B-1
- A-1
- B-2
23: How many refrigerant classifications are there for flammability?
- 1
- 7
- 2
- 3
24: Sensible heat is the heat added to a substance to
- change its state
- cause evaporation
- raise its temperature
- freeze it
25: If your suction line is warmer than the room temperature, this may indicate
- a low charge
- plugged air filter
- an over charge
- below normal superheat