Topics: All categories in the pool
1: R-22 is classified as a ____ refrigerant on the safety matrix.
- A-1
- A-2
- B-2
- B-1
2: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
- Place sign, check for leaks, and insulate suction line
- you can never change refrigerants
- Make sure its compatible, notify owner, and notify AHJ.
- Nothing must be done
3: Name three things that must be done when changing refrigeration lubricant?
- Nothing must be done
- Place sign, check for leaks, insulate
- You can't change lubricants.
- Make sure it's compatible, notify owner, notify AHJ
4: R-22 is considered a(n)
- HCFCH
- CFC
- HCFC
- HFC
5: What is the refrigerant chlorodifluoromethane?
- R-12
- R-22
- R-134a
- R-123
6: Transformers are rated in
- volts-ohms
- amps
- volts
- volt-amps
7: Class A refrigerants are considered
- flammable
- non-flammable
- non-toxic
- toxic
8: In a motor, an internal overload might open if
- there's a direct short
- there's an excess current draw through the motor
- there was a high pressure refrigerant was used for a low pressure system.
- there's an open start winding
9: An example of direct system is
- rooftop unit
- chiller
- absorber
- none of the above
10: What refrigerant is an inorganic compound?
- Ammonia
- R-132A
- R-410A
- R-22
11: At higher altitudes, boiling temperatures
- depends on the refrigerant
- decrease
- increase
- are unaffected
12: If a low-pressure chiller has a low-side leak, which of the following will most likely result?
- Low head pressure and high suction pressure
- Low suction pressure and low discharge pressure
- High suction pressure and high discharge pressure.
- High head pressure and low suction pressure
13: When the compressor is below the condensor
- traps are not needed on this type of system
- traps are needed on the oil return line
- traps are needed on the discharge line
- traps are needed on the suction line
14: A pressure relief should be located at least _______ from windows and doors.
- 20'
- 15'
- 25'
- 30'
15: 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.
16: A mercury bulb controller is not recommended for
- line voltage use
- low voltage use
- use where vibration is severe
- line or low voltage use
17: What is the temperature that a liquid and a vapor can exist in equilibrium called?
- Dry bulb temperature
- Wet bulb temperature
- Critical temperature
- Saturated temperature
18: A compressor in which the increase in vapor pressure is attained without changing the internal volume of the compression chamber is called
- non-positive displacement compressor
- negative displacement compressor
- neutral chamber-type compressor
- non-volumetric displacement compressor
19: The principle used in continuous type absorption systems is
- Charles's Law
- Dalton's Law
- Ohm's Law
- Boyle's Law
20: All machine rooms must be outfitted with a detector that _______?
- activates an audible alarm
- activates a visual alarm
- starts the ventilation system
- All of the above
21: Fusible plugs must have what marked on them?
- Melting temperature in F
- Melting temperature in C
- Opening pressure
- All of the above
22: 14.7 psia is equivalent to
- atmospheric pressure at seal level
- 29.92" Hg
- 0 psig
- All of the above.
23: In a properly balanced system with valves open and properly adjusted, if the suction line is warm to the touch, its because of
- not enough oil in the system
- oil in evaporator
- low head pressure
- moisture in the system
24: Liquid line filter-driers on a 410A system must be rated for no less than
- 1000 psig
- 600 psig
- 400 psig
- 200 psig
25: What device removes the start winding from the circuit of a split-phase motor once the motor reaches 75% of its rated load amps (RLA)?
- motor starter
- duel-voltage switch
- printed circuit board (PCB)
- centrifugal switch