Topics: All categories in the pool
1: Ammonia is under what safety classification?
- B3
- A3
- B2
- B1
2: A tachometer is an instrument used to measure
- RPM
- air velocity
- speed
- static pressure
3: R-410A can segregate in the system or chemically change its composition due to a leak.
- True
- False
4: Gauge pressure is
- Force of pressure above that of atmosphere
- Barometric pressure
- Atmospheric pressure
- Absolute pressrue
5: How far from the ground does a relief valve need to be?
- Not more than 3' above grade
- At least 25' above grade
- At least 15' above grade
- At least 20' above grade
6: All serviceable components of a refrigeration system shall be provided with
- manufactures instructions on start-up procedures
- name plates with markings referring to pressure and temperature in accordance with ASME Boiler and Pressure Vessel Code
- service manuals
- safe access
7: How are a compressor and condenser fan wired?
- parallel
- series-parallel
- parallel-series
- series
8: What will occur if the strong solution in an absorption chiller becomes too strong?
- The machine will stop cooling and solution will crystallize
- The machine will stop cooling and the solution will evaporate.
- The machine will cool excessively as the solution crystallizes.
- The machine will cool excessively as the solution evaporates
9: What is used to check very low air pressures in air conditioning duct?
- Barometer
- Vacuum gauge
- Anemomter
- Manometer
10: Two systems using separate refrigerants that are superimposed upon one another is called
- cascade
- single stage
- booster
- indirect
11: Class A refrigerants are considered
- toxic
- non-flammable
- non-toxic
- flammable
12: Before determining if a machinery room equipment is excluded from following Ashrae 15, you must determine how many pounds of refrigerant per _____ cubic feet?
- 10,000
- 100,000
- 1,000
- 100
13: Most CFC's are
- inert but toxic
- toxic
- flammable
- inert
14: Low pressure systems have what kind of compressor?
- Reciprocating
- Rotary
- Scroll
- Centrifugal
15: Low ambient controls are used when
- on air conditioning systems only
- economizers are used
- always
- when systems run all year round
16: Mercury was used in thermometers primarily because it
- was inexpensive
- expands uniformly
- never freezes
- vaporizes at very high temperatures
17: If a low-pressure chiller has a low-side leak, which of the following will most likely result?
- High suction pressure and high discharge pressure.
- Low head pressure and high suction pressure
- Low suction pressure and low discharge pressure
- High head pressure and low suction pressure
18: Dual-pressure relief devices should be installed on
- vessels of 10 cubic feet or more
- vessels of 10 cubic feet or less
- vessels of 3 cubic feet or less
- vessels of 3 cubic feet or more
19: Trichlorofluoromethane is the name of what refrigerant?
- R-11
- R-12
- R-502
- R-113
20: The location of a thermal bulb of a TXV affects
- subcooling
- the amount of liquid in the condenser.
- the amount of liquid refrigerant in the evaporator
- the amount of liquid returning to the compressor
21: Sublimation occurs when
- liquid is formed from a gas
- ice melts and turns to water
- gas is formed from a liquid
- gas is formed directly from a solid
22: 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
- 96
- 38
- 58
23: The boiling point of a refrigerant is based on
- Temperature
- Heat content
- a pressure-temperature relationship
- None of the above.
24: Oils, classified as to source, are
- naphthalene, mixed, and paraffin
- animal, vegetable, and castor
- animal, vegetable, and mineral
- naphthalene, paraffin, and castor
25: A VRF system is a direct system
- true
- false