Topics: All categories in the pool
1: The main purpose of the accumulator is to
- provide space for vapor to accumulate
- prevent liquid slugs at the compressor
- provide space for the accumulation of oil and containminants
- store liquid refrigerant
2: Humidity can be sensed with
- bimetal
- pressure bellows
- thermometer
- human hair
3: Ammonia systems use ____ pressure to adjust oil pressure
- liquid
- stream
- discharge
- air
4: What kind of system uses two different refrigerants in separate systems dependent on each other?
- Cascade
- R-414B
- Low pressure
- Simple
5: On an air cooled condenser, if the ambient air is 35F and dropping, what's its effect to the condensor?
- it would have no effect on the condenser
- it would make the condenser less efficient
- it would make the condenser more efficient
- it would cause the condenser to sweat
6: Pressure vessels with an internal volume of 10 cubic feet or more
- shall use pressure relief devices or fusible plugs
- shall use rupture discs or duel pressure relief valves
- shall use fusible plugs
- shall use pressure relief devices
7: 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
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: Before determining if a machinery room equipment is excluded from following Ashrae 15, you must determine how many pounds of refrigerant per _____ cubic feet?
- 1,000
- 100,000
- 100
- 10,000
10: Liquid refrigerant flashing, or turning to vapor, in the liquid line may be due to
- liquid line that is too small
- shortage of refrigerant
- liquid line that had too high vertical lift
- All of the above
11: Fractionation occurs when
- the pressures decreases as the heat load decreases
- when a fraction of refrigerant is added as the full charge
- some of the blended refrigerant evaporates or condenses before the rest of the blend
- the pressures increase as the heat load increases
12: The Board of Boilers adopts by reference
- MSCA Code
- Montreal Protocol Safety Code
- the 1997 ANSI/ASHRAE Safety Code
- the MACS Pressure Vessel Code of Massachusetts
13: Group A1 refrigerants over ____ pounds in a system must discharge to the atmosphere
- 330
- 110
- 6.6
- 1,000
14: A normally operating R-410A system with a condensing temperature of 110F will have a high side pressure of around ______ psig
- 255 psig
- 365 psig
- 125 psig
- 327 psig
15: A line voltage thermostat controls a 1,200 watt strip header at 120 volts. What must be minimum ampere rated of the stat be?
- 10 amps
- 15 amps
- 20 amps
- 5 amps
16: A solder joint melts at temperatures of
- 600F to 900F
- 400F to 800F
- less than 400F
- 1,200F to 1,500F
17: High side floats are used on centrifugal chiller systems are are considered critically charged systems.
- are obsolete.
- False
- depends on the type of refrigerant being used
- True
18: R-123 belongs to Group
- B-1
- B-3
- A-3
- B-2
19: A halide torch is most useful with a freon compression system
- to release a sticking valve
- to sweat flanges on the refrigeration piping
- to remove from from TXV's and evaporator coils
- to detect refrigeration leaks in piping joints
20: Heat transferred by conduction from one body to another is done
- via liquids
- via radiation
- via heat rays
- via solids
21: A hissing noise at the expansion valve is a good indication that
- expansion valve is oversized
- gas is passing thru it
- nothing is passing thru
- liquid is passing thru it
22: If the power element on an expansion valve should lose its charge, the valve would
- Over feed
- Under feed
- Close
- Stay open
23: Lithium-bromide, Li-Br, is best characterized as a
- sand
- soil
- salt
- sugar
24: Excessive head pressure is often caused by
- thermostat set too high
- air cooled condenser is plugged
- insufficient refrigerant
- leaking reed valve on the discharge side
25: A start capacitor in series with a start winding will
- decrease the amp draw of the motor
- increase running efficiency
- increase starting torque
- increase the amp draw of the motor