Topics: All categories in the pool
1: Which has more turns in the windings: Start windings or Run windings?
- Start windings
- Run windings
- They both have the exact same turns
- Depends on the system and capacitor used
2: What type of oil is used in R-410A systems?
- mineral oil
- naphthene
- polyalkylene glycol (PAG)
- polyolester (POE)
3: What is specific heat?
- measured heat
- heat required to raise the temperature of 1lb of a substance 1 degree
- the specific heat required to change the state of one cubic foot of air to steam
- none of the above
4: "I" represents ____ in the Ohm's law formula.
- voltage.
- resistance
- amperage
- capacitance
5: A plug containing an alloy that will melt at a specific temperature to relief pressure is a
- fusible plug
- relief plug
- fusion plug
- rupture plug
6: _____ and its alloys are suitable for use with ammonia systems.
- Copper
- Zinc
- Aluminum
- Magnesium
7: What is a high-side float?
- Located in the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the low side of the chiller
- Located in the liquid line entering the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the high side of the chiller
- An electronic-type metering device that contains a float assembly within the device which can accurately meter refrigerant into the evaporator as the load varies
- Located in the liquid line entering the evaporator, so when the refrigerant level is higher in the liquid line than the evaporator, the float rises to allow more refrigerant flow into the evaporator
8: Increasing superheat will do what to your frost line?
- Nothing
- Could either increase or decrease depending on the load conditions
- Decrease
- Increasae
9: What type of refrigerants are NOT flammable?
- CHC
- HFC
- HCFC
- All of the above
10: Atmospheric pressure is equal to
- 29.92" Hg
- 14.7 psia
- 14.7 psig
- both a & b
11: A pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 25
- 50
- 66
- 22
12: High side floats are used on centrifugal chiller systems are are considered critically charged systems.
- depends on the type of refrigerant being used
- True
- are obsolete.
- False
13: Control systems can be classified by
- tonnage of system
- economy of operation
- source of power
- safety
14: Liquid line filter-driers on a 410A system must be rated for no less than
- 400 psig
- 1000 psig
- 600 psig
- 200 psig
15: Oils, classified as to source, are
- naphthalene, mixed, and paraffin
- animal, vegetable, and castor
- naphthalene, paraffin, and castor
- animal, vegetable, and mineral
16: A positive displacement compressor is
- a compressor in which the increase in pressure is attained by changing the internal volume of the compression chamber
- 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
- is a reciprocating type compressor with 2 or more pistons
17: If a purge unit fails on a low pressure chiller, what are the symptoms?
- increased capacity
- low pressure chillers do not have purge units
- high head pressure
- low suction pressure
18: A total of all group A-2,B-2, A-3, and B-3 refrigerants shall not exceed ____ lb in the occupied areas and machinery rooms of institutional occupancies.
- 50
- 550
- 100
- 350
19: Which of the following controllers would you expect to be most sensitive to temperature changes?
- low voltage t-stat
- immersion controller
- aquastat
- line voltage t-stat
20: Volts x amps equals
- Impedance
- Inductance
- Watts
- Ohms Law
21: A motor is rated for 120 volts and has a RLA (rated-load amps) of 5 amps. What is the wattage of the motor?
- 1000 watts
- 600 watts
- 5KW
- 746 watts
22: A micron is
- one thousandths of a millimeter
- one millonths of a micrometer
- a larger unit of measurement than Hg
- one millonths of a centimeter
23: What is the purpose of a surge capacitor on a contactor?
- to keep the contactor pulled in
- to provide smoother start/stops
- to protect low voltage equipment
- to balance the sine waves
24: The absorber shell contains the
- evaporator and the absorber
- condenser, the evaporator, and the generator
- condenser and the absorber
- condenser and the generator
25: Fusible plugs must have what marked on them?
- Melting temperature in F
- Melting temperature in C
- Opening pressure
- All of the above