Topics: All categories in the pool
1: On a TXV, the purpose of an external equalizer is to?
- compensate for a pressure drop across the evaporator coil
- allow a greater adjustment spam
- Increase the pressure on the top of the power head diaphragm
- balance the evaporator load
2: One atmosphere equals
- 29.4
- 14.7
- 0 psig
- 0 psia
3: How far from the window does a relief valve need to be according to ASHRAE-15?
- There is no minimum for relief valve and windows.
- At least 20'
- At least 40'
- At least 30'
4: What do you need to do when you install a new system?
- Insulate the suction line before you take a superheat reading
- Add refrigerant
- Have it inspected
- Document the superheat and subcooling reading
5: What is the temperature that a liquid and a vapor can exist in equilibrium called?
- Wet bulb temperature
- Saturated temperature
- Critical temperature
- Dry bulb temperature
6: Which of the following is not an air velocity meter?
- Hydrometer
- Anemometer
- Velometer
- Anemotherm
7: What should not (and can not) be located between a pressure imposing device and a pressure-limiting device?
- Muffler
- Foot valve
- Moisture indicator
- Stop valve
8: Fusible plugs shall not be used with pressure vessels of
- 15 square feet or less
- 3 cubic feet or less
- 3 cubic feet or more
- 15 cubic feet or more
9: If a low-pressure chiller has a low-side leak, which of the following will most likely result?
- High head pressure and low suction pressure
- Low suction pressure and low discharge pressure
- High suction pressure and high discharge pressure.
- Low head pressure and high suction pressure
10: Control systems can be classified by
- safety
- tonnage of system
- economy of operation
- source of power
11: What is a high-side float?
- 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
- 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, 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 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
12: R-22 is classified as a ____ refrigerant on the safety matrix.
- A-1
- B-1
- B-2
- A-2
13: What is the purpose of suction/discharge traps?
- to ensure proper oil return to the compressor
- to keep oil inside the evaporator for proper oil return to the compressor
- to keep oil inside of the accumulator for proper return to the compressor
- all of the above
14: Booster compressors connect to the ____ side of the compressor
- vapor
- low side
- liquid
- oil side
15: Which oil is hydoscopic?
- mineral
- animal
- SW30
- polyolester
16: 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
17: B3 refrigerants are considered
- non-toxic but flammable
- non-toxic but non-flammable
- toxic but non-flammable
- toxic and highly flammable
18: The formula for Pure Power in a resistance circuit is
- Kw = volts X amps
- Watts X amps.
- Watts X power factor
- Watts = volts X amps
19: Heat transferred by conduction from one body to another is done
- via radiation
- via liquids
- via solids
- via heat rays
20: A class B1 refrigerant is considered
- non-toxic and non-flammable
- toxic but non-flammable
- toxic and somewhat flammable
- non-toxic but highly flammable
21: 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
22: No open flames are allowed in the machinery room unless?
- Approved by the authorized person
- Only when combustion air is provided from outside of the machinery room
- Approved by the installing contractor
- Never can be allowed
23: How does a centrifugal compressor create the pressure differential needed to move refrigerant through the system?
- Rotating vanes
- Fan-like action
- Suction and discharge valves
- Nesting scrolls
24: The instrument used to measure the specific gravity of absorption chiller solutions is the
- anemometer
- Psychrometer
- hydrometer
- refractometer
25: Pipe identification labels are required when the system contains more than
- 120 lbs
- 65 lbs
- 110 lbs
- 55 lbs