Topics: All categories in the pool
1: Increasing superheat will do what to your system?
- Nothing
- Increase liquid flow
- Increase gas flow
- Decrease liquid flow
2: Can you use Ammonia in industrial applications?
- When mixed with R-718
- Yes, Under certain condidtions
- Yes, always
- No, never
3: What should never be used in pressure testing refrigeration systems?
- Oxygen
- Compressed air
- Nitrogen
- Both a and b
4: 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
5: 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)?
- printed circuit board (PCB)
- duel-voltage switch
- motor starter
- centrifugal switch
6: Single compound Refrigerants are classified by what two criteria?
- Flammability and toxicity
- Flammability and temperature range
- Temperature range and hazardousness
- Weight and color
7: Liquid shall not occupy more than ____ of the volume when the temperature of the refrigerant is 90F.
- 75%
- 80%
- 100%
- 90%
8: When using nitrogen for brazing, the pressure should be:
- 125 psig
- 50-100 psig
- Very low
- Slightly below atmospheric
9: Cooling tower lowers condenser water temp by
- running fans at 100%
- evaporative cooling
- running water thru a secondary heat exchanger
- condensation
10: Which refrigerant replaced R-12?
- R-410A
- R-22
- R-407A
- R-134A
11: "R" represents ___ in the Ohm's law formula
- voltage
- resistance
- capacitance
- amperage
12: All welding done on any refrigeration system or piping covered by 522 CMR 9.00 shall be performed by a according to Section IX of the ASME code
- licensed technician
- licensed welder
- welder qualified
- competent welder
13: Ammonia (NH3) is a group III refrigerant
- True
- False
14: R-12 is
- dichloromethane
- trichlorofluoromethane
- dichlorodifluoromethane
- dichlorofluoromethane
15: Class T machine room
- shall have refrigerant leak detecting systems installed inside and outside the room
- has no flame producing apparatus permanently installed
- shall have remote controls to stop the action of the refrigerant compressor
- shall include closets used for setting equipment
16: On an air cooled condenser, if the ambient air is 35F and dropping, what's its effect to the condensor?
- it would cause the condenser to sweat
- it would make the condenser more efficient
- it would have no effect on the condenser
- it would make the condenser less efficient
17: Pressure limiting devices are not required for systems containing less then ________ refrigerants.
- 22 lbs
- 6.6 lbs
- 13.9 lbs
- 44 lbs
18: What is Absolute Zero?
- -460F
- -400F
- -640F
- -773F
19: What effect does the temperature of air have on humidity?
- warmer air holds more moisture then cooler air
- cooler air holds more moisture then warmer air
- air has no effect of humidity
- none of the above
20: Where can 50/50 solder be used on?
- suction line
- liquid line
- discharge line
- none of the above
21: R-410A is classified as a ____ refrigerant on the safety matrix.
- B-2
- A-2
- A-1
- B-1
22: Start to Run windings will have what resistance?
- The most resistance value
- The least resistance value
- All will be at equal values
- Somewhere between the actual start winding and run winding resistance value
23: A professional or office building would be considered what type of occupancy?
- public assembly
- commercial
- business
- mercantile
24: How far from the ground does a relief valve need to be?
- At least 25' above grade
- Not more than 3' above grade
- At least 20' above grade
- At least 15' above grade
25: The density of a gas refers to
- pounds per cubic foot
- cubic feet per pound
- pounds per square foot
- pounds per absolute pressure