Topics: All categories in the pool
1: Can you use Ammonia in industrial applications?
- Yes, Under certain condidtions
- When mixed with R-718
- No, never
- Yes, always
2: Can ammonia be used on domestic system?
- yes
- no
- no, unless there is proper ventilation system installed
- yes, for systems under 10 tons
3: What is the refrigerant chlorodifluoromethane?
- R-134a
- R-123
- R-22
- R-12
4: Low temperature systems should have what?
- High pour point
- Low pour point
- High viscosity
- None of the above
5: What is the temperature that a liquid and a vapor can exist in equilibrium called?
- Saturated temperature
- Critical temperature
- Wet bulb temperature
- Dry bulb temperature
6: What is a high-side float?
- 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
- 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
- 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
- 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
7: What pipe can not be used for refrigeration?
- M
- K
- N
- L
8: 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.
- 50
- 100
- 24
- 75
9: R-410A can segregate in the system or chemically change its composition due to a leak.
- True
- False
10: When using nitrogen for brazing, the pressure should be:
- Very low
- Slightly below atmospheric
- 125 psig
- 50-100 psig
11: Field Inspections of refrigeration and A/C systems in Massachusetts shall be made by
- District Engineering Inspectors
- Commissioned Inspectors
- Master licensed Technician
- both a or b
12: Which of the following is an inorganic refrigerant?
- R-22
- Ammonia
- Chlorofluorocarbons
- All of the above
13: Machinery rooms shall be vented to _____________ and utilizing mechanical ventilation.
- the outdoors
- the mechanical room housing the refrigeration system
- Machinery rooms need not be vented
- the return air ducted system
14: Transformers are rated in
- volt-amps
- volts-ohms
- volts
- amps
15: Ammonia belongs to Group
- A-1
- A-2
- B-1
- B-2
16: An accumulator can be located between the
- condenser and evaporator
- compressor and condenser
- first stage and second stage compressors
- evaporator and compressor
17: A chilled water pump suction gauge reads 10 psig. Discharge gauge reads 48 psig. The head in feet of the pump is working against
- 88
- 108
- 38
- 116
18: Class T machine room
- shall have refrigerant leak detecting systems installed inside and outside the room
- shall include closets used for setting equipment
- has no flame producing apparatus permanently installed
- shall have remote controls to stop the action of the refrigerant compressor
19: Group A2 refrigerants have a ______ toxicity rating than Group B1 refrigerants.
- the same
- lower
- higher
- there is no Group B1 refrigerants
20: On a large centrifugal system, what meters the flow to the evaporator?
- TXV
- Low side float
- Cap tube.
- High side float
21: Secondary refrigerants are usually
- Prestone anti-freeze
- expensive
- water or brine
- alcohol
22: Large Mercantile occupancy is a premise or that portion of a premise where more than ____ persons congregate on levels above or below the street level to purchase personal merchandise.
- 400
- 100
- 250
- 350
23: What type of refrigerants are NOT flammable?
- CHC
- HFC
- HCFC
- All of the above
24: Fusible plugs must have what marked on them?
- Melting temperature in F
- Melting temperature in C
- Opening pressure
- All of the above
25: What chemical in the refrigerant set off the leak detection alarm?
- Fluorine
- Chlorine
- Both A and B
- none of the above