Topics: All categories in the pool
1: Humidity can be sensed with
- bimetal
- pressure bellows
- thermometer
- human hair
2: There can be no airflow from an occupied space through a machine room unless what?
- System is high velocity
- System is ducted and sealed
- Duct is not located in the ceiling
- None of the above.
3: How many closing forces operate a thermostatic expansion valve?
- 1
- 4
- 3
- 2
4: The actual expansion curve of compressor follows most nearly which one of the following
- Adiabatic
- Isothermal
- Pressure-Temperature
- Volume
5: What type of fuses must be used on a HVAC system?
- TR Type, Duel Element, Time Delay
- Fast blow
- 10% lower than RLA
- none of the above
6: 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
7: "P" represents ______ in the Watt's law formula
- watts
- reactance
- amperage
- voltage
8: Ammonia systems use ____ pressure to adjust oil pressure
- liquid
- stream
- discharge
- air
9: What does an anemometer measure?
- velocity
- temperature
- voltage
- amperage
10: pressure relief valves must discharge to the atmosphere at a location not less than 15 feet from ground level and ____ feet from any window, ventilation opening, or exits of buildings.
- 20
- 10
- 15
- 25
11: How are a compressor and condenser fan wired?
- parallel
- parallel-series
- series
- series-parallel
12: Heat transferred by conduction from one body to another is done via:
- gas
- liquid
- solid
- All of the above
13: Low ambient controls are used when
- when systems run all year round
- always
- economizers are used
- on air conditioning systems only
14: How can you test mechanical strength of an electrical connection?
- measure ohms with an electrical meter
- measure voltage across the connection
- attempt to pull the wire from the connector by hand
- none of the above.
15: How do you find net oil pressure on a compressor?
- discharge pressure - suction pressure
- gross oil pressure - suction pressure
- gross oil pressure - discharge pressure
- all of the above
16: The leaving chilled water set point for comfort cooling is typically?
- 60
- 38
- 45
- 66
17: A Lithium-bromide system is an absorption system that
- uses salts as an absorbent and lithium bromide as a refrigerant
- uses ammonia as a refrigerant and lithium bromide as an absorbent
- uses water as a refrigerant and lithium bromide as an absorbent
- uses water as a absorbent and lithium bromide as a refrigerant
18: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
- 75%
- 80%
- 99%
- 90%
19: The actual expansion curve of compression follows most nearly which one of the following curves?
- Adiabatic
- Isothermal
- Pressure Temperature
- Volume Temperature
20: Indirect systems using Group II refrigerants
- shall be used in refrigeration system less than 1,000 lbs
- shall be used for mechanical equipment only
- shall have all refrigerant containing parts except piping, installed in a Class T machine room
- shall be used in refrigeration system in excess of 1,000 lbs
21: Joints in piping for refrigeration containing parts must withstand temperatures of ___?
- 800F
- 700F
- 1000F
- 600F
22: Lithium-bromide, Li-Br, is best characterized as a
- sand
- soil
- salt
- sugar
23: 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
- purge
- splurge
- surge
- merge
24: Refrigeration piping before being buried shall be
- leak tested
- encased in pipe duct
- pressure tested
- All of the above
25: 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