Topics: All categories in the pool
1: What is an egress?
- A valve put on the low side of the system to prevent frosting
- An escape route
- A code violation
- An entrance or exit
2: Heat is a form of
- matter
- energy
- power
- work
3: Laten heat is associated with a change in state of a refrigerant but not temperature
- True
- False
4: What should never be used in pressure testing refrigeration systems?
- Oxygen
- Compressed air
- Nitrogen
- Both a and b
5: High side floats are used on centrifugal chiller systems are are considered critically charged systems.
- False
- are obsolete.
- depends on the type of refrigerant being used
- True
6: In an air conditioning system, the unit of total heat energy content in an air/vapor mixture is
- Enthalpy
- Specific heat
- Latent heat
- Sensible heat
7: On a single phase motor, when does the start winding cut out?
- At 75% of its full rated speed
- Start windings do no cut-out of the run cycle
- At 25% of its full rated speed
- At 50% of its full rated speed
8: The most common type of motor starter is
- delts-wye starter
- duel-winding starter
- across the line starter
- part winding starter
9: What is used to check very low air pressures in air conditioning duct?
- Vacuum gauge
- Manometer
- Anemomter
- Barometer
10: In a low temperature refrigeration system, the benefit of the system using P.A.G. oil is
- it is hydroscopic
- it traps moisture
- viscosity
- all of the above
11: A normally operating R-410A system with a condensing temperature of 110F will have a high side pressure of around ______ psig
- 365 psig
- 327 psig
- 125 psig
- 255 psig
12: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is
- .8
- 1.2
- .1
- 1.7
13: Fractionation occurs when
- some of the blended refrigerant evaporates or condenses before the rest of the blend
- the pressures decreases as the heat load decreases
- the pressures increase as the heat load increases
- when a fraction of refrigerant is added as the full charge
14: Aluminum, Zinc, Magnesium, or their alloys shall not be used in contact with
- methyl chloride
- ammonia
- R-718
- trichlorotrifluoromethane
15: What is the purpose of suction/discharge traps?
- to ensure proper oil return to the compressor
- to keep oil inside the evaporator for proper oil return to the compressor
- to keep oil inside of the accumulator for proper return to the compressor
- all of the above
16: By using nitrogen within a pipe during brazing operation,
- The explosion hazard is confined
- Discoloration is prevented
- Exterior scale formation is minimized
- Copper oxide formation is prevented
17: Group A1 refrigerants over ____ pounds in a system must discharge to the atmosphere
- 1,000
- 6.6
- 110
- 330
18: Which refrigerant was still able to be vented to the atmosphere after July 1, 1992?
- R-22
- R-12
- R-11
- R-113
19: R-123 belongs to Group
- B-1
- B-2
- A-3
- B-3
20: Usually dry bulb temperature is
- same as wet bulb temperature
- lower than dry bulb temperature
- higher than wet bulb temperature
- not important and shall be ignored
21: Brazed joints melt at temperatures above
- 1,200F
- 1,000F
- 800F
- 500F
22: Relief valves are rated in
- pounds of air per hour
- pounds of air per minute
- gallons of water per hour
- gallons of water per minute
23: The certificate of inspection
- shall be $20 and an additional fee of $1 for each tone above 20 tons
- shall be posted and protected from dirt, water, and other elements
- shall be authorized by a notarized insurance company
- shall be posted on the compressor shell or electrical panel at the unit
24: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
- 75%
- 99%
- 80%
- 90%
25: A person holding a license as a refrigeration technician may connect or disconnect for the purpose of installation, repair, or replacement, any electrical device or control to be a part of a refrigeration or air conditioning system, from the
- 24 volt secondary side of the Class 2 transformer to the thermostat
- first disconnect in
- breaker panel in
- load-side of the contactor in