Topics: All categories in the pool
1: What refrigerant were phased out in 2004?
- R-12
- R-22
- R-11
- R-134a
2: Fusible plugs must have what marked on them?
- Melting temperature in F
- Melting temperature in C
- Opening pressure
- All of the above
3: A rule of thumb in air conditioning is ____ CFM per ton?
- 100
- 400
- 600
- 500
4: Laten heat is associated with a change in state of a refrigerant but not temperature
- True
- False
5: Institutional occupancy is
- a premise or that portion of a premise where large numbers of people congregate and from which occupants cannot quickly vacate the space.
- a premise or that portion of a premise from which, because they are disabled, debilitated, or confined, occupants cannot readily leave without the assistance of others.
- a premise or that portion of a premise where people transact business, receive personal service, or purchase food and other goods.
- None of the above
6: Liquid level gauge glasses shall have automatic closing shut off valves, except Bull's eye or reflex type.
- True
- False
7: A cross charged power element on an expansion valve would normally be used in what temperature range?
- 0F-38F
- 30F to 50F
- -100F to -40F
- -40F to 0F
8: Which of the following are considered inorganic refrigerants?
- R-717 and R-718
- 410A and R-407C
- R-500 and R-502
- None of the above
9: A device used to measure small pressure differences is the
- anemometer
- phsycometirc
- pyrometer
- manometer
10: All low-pressure chillers use which type of compressor?
- Reciprocating
- Scroll
- Rotary
- Centrifugal
11: Foaming of oil in a compressor is most likely to occur
- when the evaporator temperatures are below 32F
- at start-up
- when ambient temperature are low
- when there is insufficient air across the condenser(i.e., dirty coil)
12: Name a CFC refrigerant(s):
- R-11
- R-12
- R-123
- both a & b
13: The high side float assembly meters refrigerant into the evaporator through the
- upper chamber of the high side
- upper chamber of the low side
- lower chamber of the high side
- lower chamber of the low side
14: Low ambient controls are used when
- on air conditioning systems only
- always
- when systems run all year round
- economizers are used
15: When is the only time you can leave a service container attached to a system?
- Leaking system
- Recovery
- Charging
- Both b and c
16: Watt's Law indicates Volts X Amps = _________.
- Ohms
- Watts
- Current
- Resistance
17: What should never be used in pressure testing refrigeration systems?
- Oxygen
- Compressed air
- Nitrogen
- Both a and b
18: 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
- lift voltage
- boost voltage
- pick-up voltage
- run voltage
19: The critical temperature of a refrigerant gas occurs when
- any increase in pressure will not liquefy the gas
- the gas returns to a liquid
- the gas is no longer saturated
- any decrease in pressure will cause condensation
20: Pressure vessels of 10 cubic feet or more gross volume shall use
- at least one rupture member
- a dual pressure-relief valve if charging into the atmosphere
- at least three means of discharge and/or rupture discs
- both a and b are correct
21: Cooling tower lowers condenser water temp by
- condensation
- evaporative cooling
- running water thru a secondary heat exchanger
- running fans at 100%
22: What will occur if the strong solution in an absorption chiller becomes too strong?
- The machine will stop cooling and the solution will evaporate.
- The machine will stop cooling and solution will crystallize
- The machine will cool excessively as the solution evaporates
- The machine will cool excessively as the solution crystallizes.
23: Two systems using separate refrigerants that are superimposed upon one another is called
- booster
- single stage
- cascade
- indirect
24: The best way to determine the voltage requirement for an electrical component is to
- read the nameplate data
- read the voltage with a mulitmeter
- check with the utility company
- determine the capacity of the service panel
25: Class 3 refrigerants are
- non-flammable
- non-toxic
- highly flammable
- toxic