Topics: All categories in the pool
1: When energized, a normally open relay will be
- open
- closed
- noisy
- depends on the type and class of the relay
2: A start capacitor in series with a start winding will
- increase the amp draw of the motor
- decrease the amp draw of the motor
- increase running efficiency
- increase starting torque
3: What is the voltage of each leg to ground of a three-phase motor with a 460v supply voltage?
- 208v
- 120v
- 277v
- 240v
4: On a 460V motor, what is he MAXIMUM voltage that can be safely applied to it?
- 506v
- 550v
- 660v
- None of the above
5: How far from the ground does a relief valve need to be?
- At least 25' above grade
- At least 20' above grade
- At least 15' above grade
- Not more than 3' above grade
6: What measures gas pressure?
- Hygrometer
- Manometer
- Barometer
- Hydrometer
7: The purpose of a receiver is
- a vessel to store refrigerant outside the system
- to increase the capacity that the system can hold
- to use a a later date
- all of the above
8: Give an example of a secondary coolant?
- R-717
- R-12
- R-410A
- R-718
9: If air is present in an absorption chilled water appliance, which of the following will most likely occur?
- Rust can form
- System operating pressure will drop
- The Li-Br solution will become more diluted
- The Li-Br solution will become more concentrated
10: If a refrigerant leaving the condenser is 94F and the condensing temperature is 105F, the subcooling is
- 11F
- 9F
- 21F
- 29F
11: The generator shell contains the
- condenser and the generator
- condenser, the evaporator, and the generator
- evaporator and the absorber
- condenser and the absorber
12: A motor is rated for 120 volts and has a RLA (rated-load amps) of 5 amps. What is the wattage of the motor?
- 746 watts
- 5KW
- 600 watts
- 1000 watts
13: Which refrigerant(s) is an HFC?
- R-22
- R-410A
- R-502
- All of the above
14: Class 3 refrigerants are
- non-toxic
- highly flammable
- non-flammable
- toxic
15: What is a Category "D" fluid?
- A typical refrigerant used on newer air conditioning and heat pump ssytems
- Any fluid that exceeds 150 psig and has design temperature of over 366F
- A toxic fluid, which can produce serious irreversible harm to persons on breathing or bodily contact
- A fluid which is nonflammable, nontoxic, not damaging to human tissues, does not exceed 150 psig, and design temperature is between -20F to 366F
16: The ____ design is the maximum pressure for which a specific part of a refrigeration system is designed.
- high pressure
- critical pressure
- low pressure
- design pressure
17: Laten heat is associated with a change in state of a refrigerant but not temperature
- True
- False
18: If your suction line is warmer than the room temperature, this may indicate
- an over charge
- plugged air filter
- below normal superheat
- a low charge
19: How is bring measured?
- anemometer
- hydrometer
- hygrometer
- manometer
20: Low temperature systems should have what?
- High pour point
- Low pour point
- High viscosity
- None of the above
21: What percentage of amperage difference is allowable phase to phase on a HVAC circuit phased to phase?
- 1%
- 4%
- 25%
- 2%
22: What device should be used on low-temperature freezers?
- high capacity TXV
- discharge muffler
- oil separator
- hot-gas by-pass
23: Pipe identification labels are required when the system contains more than
- 110 lbs
- 55 lbs
- 120 lbs
- 65 lbs
24: Viscosity is
- the ability of oil to flow
- measure of weight
- the coefficient of external friction
- a measure of heat content
25: The leaving chilled water set point for comfort cooling is typically?
- 60
- 45
- 38
- 66