Topics: All categories in the pool
1: What is the temperature that a liquid and a vapor can exist in equilibrium called?
- Dry bulb temperature
- Critical temperature
- Wet bulb temperature
- Saturated temperature
2: A High-Probability System
- is such that a leak of refrigerant from a failed connection will enter the occupied space
- is a system highly likely to leak form a failed connection or component of such system
- is such that any leak will cause injury or death to anyone within a 100 square foot area
- is such that a leak of refrigerant from a failed connection will enter an unoccupied space
3: Fusible plugs shall not be used with pressure vessels of
- 3 cubic feet or more
- 3 cubic feet or less
- 15 square feet or less
- 15 cubic feet or more
4: A motor starter is a device that includes an overload and a _______?
- contactor
- 2-pole contacts
- duel-coil
- all of the above
5: What device should be used on low-temperature freezers?
- high capacity TXV
- oil separator
- discharge muffler
- hot-gas by-pass
6: How many square inches per square foot?
- 98
- 64
- 144
- 24
7: Ammonia can come in contact with _______ ?
- Aluminum
- Copper tubing
- Brass
- Copper
8: Indirect systems using Group II refrigerants
- shall be used in refrigeration system less than 1,000 lbs
- shall be used for mechanical equipment only
- shall have all refrigerant containing parts except piping, installed in a Class T machine room
- shall be used in refrigeration system in excess of 1,000 lbs
9: Methyl Chloride is a halogenated refrigerant and should not come in contact with
- aluminum
- zinc
- magnesium
- all of the above
10: How many opening forces operate a thermostatic expansion valve?
- 2
- 4
- 1
- 3
11: Pipe identification labels are required when the system contains more than
- 65 lbs
- 55 lbs
- 110 lbs
- 120 lbs
12: Liquid level gauges shall have _____________ with one exception being that of the liquid level gauge bull’s eye type.
- color-coded glass to determine type of refrigerant
- moisture indicators
- automatic closing shut-off valves
- All of the above
13: A hissing noise at the expansion valve is a good indication that
- expansion valve is oversized
- nothing is passing thru
- liquid is passing thru it
- gas is passing thru it
14: Start to Run windings will have what resistance?
- The most resistance value
- Somewhere between the actual start winding and run winding resistance value
- The least resistance value
- All will be at equal values
15: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
- 80%
- 99%
- 75%
- 90%
16: What do you need to do when you install a new system?
- Have it inspected
- Document the superheat and subcooling reading
- Insulate the suction line before you take a superheat reading
- Add refrigerant
17: Refrigerant systems containing Group I refrigerants can be installed in or on public stairways.
- True
- False
18: What is the typical air conditioning operating pressures for R-22?
- 60 psi suction 210 psi discharge
- 25 psi suction 125 psi discharge
- 105 psi suction 340 psi discharge
- None of the above
19: In a system designed for sub-zero ambient temperatures, what must be added?
- Infrared dye for leak identification
- Low-ambient kit
- Nitrogen
- Booster compressor
20: When energized, a normally open relay will be
- closed
- depends on the type and class of the relay
- open
- noisy
21: Control systems can be classified by
- safety
- source of power
- tonnage of system
- economy of operation
22: What is not a requirement of a Class T machine room?
- Tight fitting doors
- Self-closing doors
- Fire hose connected to the building fire protection system.
- Automatic ventilation
23: A Lithium-bromide system is an absorption system that
- uses water as a absorbent and lithium bromide as a refrigerant
- uses ammonia as a refrigerant and lithium bromide as an absorbent
- uses salts as an absorbent and lithium bromide as a refrigerant
- uses water as a refrigerant and lithium bromide as an absorbent
24: Halogen refrigerants are corrosive to which type of metal?
- copper
- black iron
- magnesium
- stainless steel
25: When an A/C system is excessively low on refrigerant
- it can become contaminated with water
- there can be nuisance trip outs
- the suction line may be too hot to touch
- All of the above