Topics: All categories in the pool
1: An azeotropic refrigerant is
- a mixture of two or more refrigerants that boil at about the same temperature minimizing temperature glide.
- a mixture of two or more refrigerants that boil at much different temperatures causing temperature glide
- a mixture of two or more refrigerants that boil at much different temperatures minimizing temperature glide
- none of the above
2: Megaohm meters can detect a ground in the
- 10,000,000 ohms or higher
- up to 10,000 ohms
- up to 1,000,000 ohms
- up to 1,000 ohms
3: Who is permitted to access a refrigeration machine room?
- Authorized persons only
- Contractors only
- Anyone, it's a completely safe area
- Any employee
4: On a centrifugal compressor, stationary diffuser vanes are needed to
- prevent high pressure on the packing
- convert velocity energy to pressure
- stop gas flow
- increase the clearance space
5: All serviceable components of a refrigeration system shall be provided with
- service manuals
- safe access
- manufactures instructions on start-up procedures
- name plates with markings referring to pressure and temperature in accordance with ASME Boiler and Pressure Vessel Code
6: The instrument used to measure the specific gravity of absorption chiller solutions is the
- anemometer
- refractometer
- Psychrometer
- hydrometer
7: A device used to measure small pressure differences is the
- manometer
- anemometer
- phsycometirc
- pyrometer
8: B3 refrigerants are considered
- non-toxic but flammable
- non-toxic but non-flammable
- toxic but non-flammable
- toxic and highly flammable
9: What type of refrigerants are NOT flammable?
- CHC
- HFC
- HCFC
- All of the above
10: Where are the three places that the discharge from an ammonia relief valve be piped?
- To chemical neutralizing tank only
- Underground, into drain, into mechanical room
- Atmosphere, Tank containing water, where the AHJ indicates.
- None of the above.
11: What is not a requirement of a class T machine room?
- automatic ventilation
- self-closing doors
- fire hose connection to the building fire protection system
- tight fitting doors
12: Methyl Chloride is a halogenated refrigerant and should not come in contact with
- aluminum
- zinc
- magnesium
- all of the above
13: The location of the thermal bulb for the TXV on the evaporator effects
- both the pressure and temperature in the feeler bulb
- the amount of superheat required to operate the TXV
- the amount of liquid in the evaporator
- the amount of gas in the evaporator
14: What was the main reason for enacting the no venting rule of July 1, 1992?
- Ozone depletion
- Green house effect
- Global warming potential
- All of the above
15: If a condenser is on a roof and the temperature is 35F and dropping the capacity
- run as designed with low ambient controls
- doesn't change
- decreases
- increases
16: Which of the following is an example of an azeotropic refrigerant?
- R-134A
- R-500
- R-410A
- R-404A
17: The difference between saturated liquid and saturated vapor is
- heat
- volume
- temperature
- pressure
18: The outer portion of shell of the compressor used on low-pressure chillers is called the
- suction
- nozzle
- volute
- baffle
19: NH3 is
- ammonia
- lithium bromide
- R-718
- R-508A
20: A motor starter contains a thermal overload and a
- 3-way relay
- solenoid
- contactor
- transformer
21: Stop valves shall not be permitted between the system and the
- condenser
- bleed valve
- service valve
- relief valve
22: What is the purpose of a surge capacitor on a contactor?
- to balance the sine waves
- to protect low voltage equipment
- to keep the contactor pulled in
- to provide smoother start/stops
23: The ____ design is the maximum pressure for which a specific part of a refrigeration system is designed.
- high pressure
- low pressure
- critical pressure
- design pressure
24: Mercury was used in thermometers primarily because it
- never freezes
- expands uniformly
- was inexpensive
- vaporizes at very high temperatures
25: Low pressure systems have what kind of compressor?
- Rotary
- Reciprocating
- Centrifugal
- Scroll