Topics: All categories in the pool
1: How many forces operate a thermostatic expansion valve?
- 4
- 3
- 1
- 2
2: The two float-type metering devices are the
- liquid float and the vapor float
- liquid float and the low-side float
- vapor float and the low-side float.
- high-side float and the low-side float
3: A rule of thumb in air conditioning is ____ CFM per ton?
- 500
- 400
- 100
- 600
4: 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
5: Thermodynamics is the branch of science that deals with
- molecular therory
- energy due to motion
- heat energy
- state of energy
6: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
- 80%
- 99%
- 75%
- 90%
7: On a large centrifugal system, what meters the flow to the evaporator?
- TXV
- High side float
- Low side float
- Cap tube.
8: Stop valves shall not be permitted between the system and the
- condenser
- bleed valve
- relief valve
- service valve
9: Can you use Ammonia in industrial applications?
- When mixed with R-718
- No, never
- Yes, always
- Yes, Under certain condidtions
10: What is not a requirement of a Class T machine room?
- Tight fitting doors
- Automatic ventilation
- Self-closing doors
- Fire hose connected to the building fire protection system.
11: A class B1 refrigerant is considered
- toxic but non-flammable
- non-toxic but highly flammable
- toxic and somewhat flammable
- non-toxic and non-flammable
12: One watt of electrical energy in a resistive heater will provide _____ BTU/hr
- 3.415
- 34.15
- 16.64
- 6.830
13: What are the three components of a transformer?
- Primary coil, secondary coil, and copper contacts
- Primary coil, secondary coil, and core
- Primary core, secondary coil, and high and low voltage connectors.
- Contacts, secondary coil, and core
14: Methyl Chloride is a halogenated refrigerant and should not come in contact with
- aluminum
- zinc
- magnesium
- all of the above
15: On a centrifugal compressor, stationary diffuser vanes are needed to
- increase the clearance space
- convert velocity energy to pressure
- prevent high pressure on the packing
- stop gas flow
16: When energized, a normally open relay will be
- closed
- open
- depends on the type and class of the relay
- noisy
17: In a motor, an internal overload might open if
- there's an open start winding
- there's an excess current draw through the motor
- there's a direct short
- there was a high pressure refrigerant was used for a low pressure system.
18: What refrigerant were phased out in 2004?
- R-11
- R-22
- R-12
- R-134a
19: Low ambient controls are used when
- on air conditioning systems only
- economizers are used
- always
- when systems run all year round
20: Laten heat is associated with a change in state of a refrigerant but not temperature
- True
- False
21: How much clearance do you need around the perimeter of electrical panels?
- 18"
- 24"
- 36"
- 12"
22: Pressure relief valves shall be marked with the data from
- Section I Division VIII of ASME Boiler & Pressure Code
- Section XIII Division of the ASME Boiler & Pressure Code
- Section IV Division of the ASME Boiler & Pressure Code
- Section VIII Division of the ASME Boiler & Pressure Code
23: Ammonia can come in contact with _______ ?
- Aluminum
- Copper tubing
- Brass
- Copper
24: Electricity involves the movement of electrons in atoms
- True
- False
25: Where are the three places that the discharge from an ammonia relief valve be piped?
- To chemical neutralizing tank only
- Underground, into drain, into mechanical room
- Atmosphere, Tank containing water, where the AHJ indicates.
- None of the above.