Topics: All categories in the pool
1: 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
2: If two 500 ohm resistors are connected in series, the resistance will be
- 500 ohms
- 20 ohms
- 200 ohms
- 1000 ohms
3: What refrigerant were phased out in 2004?
- R-22
- R-11
- R-134a
- R-12
4: Evaporators located ____inches of a heating coil shall be equipped whit a pressure relief device.
- 15
- 18
- 24
- 10
5: It takes how many BTU/hr to melt one pound of ice at 32F
- 970
- 212
- 180
- 144
6: Which refrigerant(s) is an HFC?
- R-22
- R-410A
- R-502
- All of the above
7: Megaohm meter's main function is
- to detect weak motor winding insulation of a refrigeration or air conditioning compressor by creating high DC voltages to the compressor
- to detect very high resistances to ground of refrigeration or air conditioning compressors
- to test very high value capacitors for large 3-phase refrigeration compressors and blower motors.
- Both a and b are correct
8: A declaration test is needed when the system contains more than
- 65 lbs
- 55 lbs
- 110 lbs
- 120 lbs
9: R-22 falls under which safety classification?
- B-1
- A-2
- B-2
- A-1
10: What is the leaving chilled water set point for water chiller systems?
- 45F
- 55F
- 38F
- 66F
11: A moisture indicator must
- be filled with liquid
- change color when exposed to moisture
- be yellow
- be sight side up
12: Two systems using separate refrigerants that are superimposed upon one another is called
- booster
- indirect
- cascade
- single stage
13: Which of the following is an inorganic refrigerant?
- R-22
- Ammonia
- Chlorofluorocarbons
- All of the above
14: Ammonia (NH3) is a group III refrigerant
- True
- False
15: A hotel is considered a _______ occupancy.
- institutional
- commercial
- residential
- mercantile
16: Setting a pressure relief device shall not exceed ___ of the design pressure
- 90%
- 80%
- 100%
- 75%
17: Brazed joints melt at temperatures above
- 800F
- 500F
- 1,000F
- 1,200F
18: NH3 is
- R-508A
- ammonia
- R-718
- lithium bromide
19: After setting up a forward curved fan for the desired conditions, something happened to lower the total static pressure the fan had to operate against. Which would occur?
- CFM and RPM decrease
- RPM and CFM increase
- CFM and HP increase
- CFM and HP decrease
20: Halo-carbon refrigerants cannot be used with what material?
- Aluminum
- Copper
- Stainless Steel
- Magnesium alloy
21: What type of oil is used in R-410A systems?
- polyalkylene glycol (PAG)
- mineral oil
- polyolester (POE)
- naphthene
22: How many closing forces operate a thermostatic expansion valve?
- 1
- 4
- 2
- 3
23: In an air conditioning plant which an indirect low side, water is used inside of bring: the proper sequence of operating the plan is
- reset the expansion valve
- reset the safety valve
- start the fan and circulating pump
- start the comrpessor
24: What is the minimum height refrigeration piping should be placed against walls?
- 72"
- Ceiling height
- 6'
- 7.25'
25: At higher altitudes, the boiling point of refrigerant is
- equal to the coefficient of water at 32F
- higher
- the same
- lower