Topics: All categories in the pool
1: Two systems using separate refrigerants that are superimposed upon one another is called
- single stage
- booster
- indirect
- cascade
2: A chilled water pump's suction gauge reads 10 psig. The discharge gauge reads 48 psig. What is the head in feet the pump is working against?
- 88
- 38
- 58
- 96
3: What is not a requirement of a class T machine room?
- tight fitting doors
- fire hose connection to the building fire protection system
- self-closing doors
- automatic ventilation
4: Heat cannot of itself, pass from a
- cold to a warmer body
- warm to a colder body
- state of hot energy to a state of cold energy
- None of the above
5: If the compression ratio on a centrifugal compressor rises too high, the compressor will stop pumping and make a loud sound commonly referred to as a
- merge
- splurge
- purge
- surge
6: Large mercantile occupancy is
- 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 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 50 persons congregate on levels above of below street level to purchase personal merchandise.
- 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
7: In an air conditioning system, the unit of total heat energy content in an air/vapor mixture is
- Specific heat
- Sensible heat
- Latent heat
- Enthalpy
8: Which refrigerant is lighter than air?
- R-134a
- R-123
- R-717
- R-11
9: R-22 is considered a(n)
- CFC
- HCFCH
- HFC
- HCFC
10: Pressure vessels with an internal volume of 3 cubic feet or more
- shall use fusible plugs
- do not need pressure relief protection
- shall use pressure relief devices or fusible plugs
- shall use pressure relief devices
11: Liquid line filter-driers on a 410A system must be rated for no less than
- 200 psig
- 400 psig
- 1000 psig
- 600 psig
12: The ____ design is the maximum pressure for which a specific part of a refrigeration system is designed.
- high pressure
- critical pressure
- design pressure
- low pressure
13: Defined process piping by code CMR (528)
- Any piping that conveys a solid, liquid or gas that is not part of the plumbing or fire protection system
- Any piping in an industrial space
- Any piping in an industrial or commercial space
- All of the above
14: What is a Category "M" fluid?
- A toxic fluid, which can produce serious irreversible harm to persons on breathing or bodily content
- Any fluid that exceeds 150 psig and has design temperatures over 366F
- A typical refrigerant used on newer air conditioning and heat pump systems
- A fluid which is nonflammable, nontoxic, not damaging to human tissues, does not exceed 150 psig, and the designed temperature is between -20F to 366F
15: 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
16: If the dry bulb temperature is 85F and the wet bulb temperature is 70F, the dew point temperature will be approximately (use psychometric chart)
- 77F
- 58F
- 70F
- 32F
17: Increasing superheat will do what to your frost line?
- Increasae
- Nothing
- Decrease
- Could either increase or decrease depending on the load conditions
18: A 50 VA control transformer with a 25 volt control output would be rated for _________ amps.
- 2.5
- 1250
- 2
- There isn't enough information to answer.
19: How many refrigerant classifications are there for flammability?
- 7
- 3
- 1
- 2
20: The level of voltage caused by back electromagnetic force that opens the contacts of a potential relay in order to take the start capacitor out of the circuit is
- pick-up voltage
- boost voltage
- run voltage
- lift voltage
21: If the power element on an expansion valve should lose its charge, the valve would
- Close
- Over feed
- Under feed
- Stay open
22: When a receiver is greater than 3 cubic feet but less than 10 cubic feed, what is the minimum relief device required?
- fusible plug
- relief valve
- rupture disc
- all of the above
23: What chemical in the refrigerant set off the leak detection alarm?
- Fluorine
- Chlorine
- Both A and B
- none of the above
24: How does a centrifugal compressor create the pressure differential needed to move refrigerant through the system?
- Suction and discharge valves
- Fan-like action
- Nesting scrolls
- Rotating vanes
25: Transformers are rated in
- amps
- volts
- volt-amps
- volts-ohms