Topics: All categories in the pool
1: What are the three components of a transformer?
- Primary core, secondary coil, and high and low voltage connectors.
- Primary coil, secondary coil, and core
- Contacts, secondary coil, and core
- Primary coil, secondary coil, and copper contacts
2: Which is the lowest vacuum?
- 1,000 Microns
- 5 psig
- 5" hg
- 10 psia
3: R-410A can segregate in the system or chemically change its composition due to a leak.
- True
- False
4: How many closing forces operate a thermostatic expansion valve?
- 1
- 4
- 2
- 3
5: Single compound Refrigerants are classified by what two criteria?
- Flammability and temperature range
- Weight and color
- Temperature range and hazardousness
- Flammability and toxicity
6: The proper location for an oil separator is between the
- condenser and receiver
- compressor and condenser
- evaporator and compressor
- receiver and metering device
7: A motor starter contains a thermal overload and a
- contactor
- solenoid
- transformer
- 3-way relay
8: A pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 22
- 25
- 50
- 66
9: On a centrifugal compressor, stationary diffuser vanes are needed to
- stop gas flow
- prevent high pressure on the packing
- convert velocity energy to pressure
- increase the clearance space
10: The instrument used to measure the specific gravity of absorption chiller solutions is the
- anemometer
- hydrometer
- refractometer
- Psychrometer
11: Starting relays for a single phase compressors are used to remove the starting circuit from operation when the motor reaches approximately ____ percent of its speed.
- 24
- 100
- 75
- 50
12: Dual-pressure relief devices should be installed on
- vessels of 10 cubic feet or more
- vessels of 3 cubic feet or less
- vessels of 10 cubic feet or less
- vessels of 3 cubic feet or more
13: Where are the three places that the discharge from an ammonia relief valve be piped?
- atmosphere, tank containing water, where the A.H.J. indicates
- underground, into drain, into mechanical room
- to chemical neutralizing tank only
- none of the above
14: Which of the following types of oils are hygroscopic?
- polyolester (POE)
- polyalkylene glycol (PAG)
- naphthene mineral
- both a and b
15: Group A3 refrigerants have a ______ flammability rating than Group B1 refrigerants
- lower
- the same
- there is no Group B1 refrigerants
- higher
16: 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
17: A chiller entering and leaving temperature difference is?
- 10 degrees F
- 5 degrees F
- 50 degrees F
- 20 degrees F
18: A positive displacement compressor is
- is a reciprocating type compressor with 2 or more pistons
- where the compressor's suction pressure and the compressor;s discharge pressure is more than 50 PSI
- a compressor in which the increase in pressure is attained by changing the internal pressure of the compression chamber
- a compressor in which the increase in pressure is attained by changing the internal volume of the compression chamber
19: What percentage of amperage difference is allowable phase to phase on a HVAC circuit phased to phase?
- 4%
- 1%
- 2%
- 25%
20: All low-pressure chillers use which type of compressor?
- Scroll
- Centrifugal
- Rotary
- Reciprocating
21: High pressure controls should be set no higher than
- 10% of set point
- 80% of set point
- 25% of set point
- 90% of set point
22: When this is installed on the high side of a system, it must be capable of reading 1.2 times the design pressure (ASHRAE 15 9.11.3)
- Pressure gauge
- Temperature gauge
- Sight glass gauge
- All of the above
23: Name an HCFC refrigerant(s):
- R-22
- R-123
- R-11
- both a & b
24: What refrigerant is an inorganic compound?
- R-410A
- R-22
- R-132A
- Ammonia
25: What is not a requirement of a Class T machine room?
- Self-closing doors
- Tight fitting doors
- Automatic ventilation
- Fire hose connected to the building fire protection system.