Topics: All categories in the pool
1: Trichlorofluoromethane is the name of what refrigerant?
- R-12
- R-113
- R-502
- R-11
2: Large vessels containing refrigerant ______________________ from using two or more pressure-relief devices in parallel to obtain the required capacity.
- shall not be prohibited
- shall be prohibited
- containing R-11, R-123 & R-717 exclusively shall not be prohibited
- of Group B2 refrigerant shall be prohibited
3: Pressure vessels of 10 cubic feet or more gross volume shall use
- at least one rupture member
- a dual pressure-relief valve if charging into the atmosphere
- at least three means of discharge and/or rupture discs
- both a and b are correct
4: A run capacitor is wired in series with the _____ windings.
- start capacitor
- start
- common
- run
5: Megaohm meters can detect a ground in the
- up to 10,000 ohms
- 10,000,000 ohms or higher
- up to 1,000 ohms
- up to 1,000,000 ohms
6: Pressure vessels shall be provided with ___________in accordance with Section VIII of the ASME Boiler & Pressure Vessel Code
- over pressure protection and a rupture disc
- Pressure vessels need no type of protection as long as it is hydrostatically tested every three months
- over pressure protection as well as a temperature protection device
- over pressure protection
7: Liquid line filter-driers on a 410A system must be rated for no less than
- 600 psig
- 1000 psig
- 200 psig
- 400 psig
8: Which refrigerant replaced R-12?
- R-410A
- R-134A
- R-22
- R-407A
9: The boiling point of a refrigerant is based on
- Temperature
- Heat content
- a pressure-temperature relationship
- None of the above.
10: What is the purpose of a surge capacitor on a contactor?
- to balance the sine waves
- to keep the contactor pulled in
- to provide smoother start/stops
- to protect low voltage equipment
11: In designing duct work, pressure and ______ need to be considered
- length
- CFM
- duct sealant used
- all of the above
12: A compressor in which the increase in vapor pressure is attained without changing the internal volume of the compression chamber is called
- negative displacement compressor
- non-positive displacement compressor
- non-volumetric displacement compressor
- neutral chamber-type compressor
13: R-22 falls under which safety classification?
- A-2
- B-1
- A-1
- B-2
14: Halogenated refrigerants cannot be used with what material?
- Stainless steel
- Aluminum
- Magnesium alloy
- Copper
15: On a TXV, the purpose of an external equalizer is to?
- allow a greater adjustment spam
- compensate for a pressure drop across the evaporator coil
- balance the evaporator load
- Increase the pressure on the top of the power head diaphragm
16: Lithium-bromide, Li-Br, is best characterized as a
- salt
- sand
- sugar
- soil
17: Which is considered the more efficient condenser?
- water cooled
- air cooled
- spray cooled
- fan cooled
18: Gauge pressure is
- Force of pressure above that of atmosphere
- Barometric pressure
- Absolute pressrue
- Atmospheric pressure
19: On a large centrifugal system, what meters the flow to the evaporator?
- Cap tube.
- Low side float
- TXV
- High side float
20: R-12 is
- dichlorofluoromethane
- dichloromethane
- trichlorofluoromethane
- dichlorodifluoromethane
21: 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
22: Each machinery room shall contain
- high and low pressure controls
- a toxicity detector where the presence of ammonia or lithium bromide from a leak will concentrate
- smoke and fire alarms as well as three means of egress and that egress must meet 528 CMR ventilation requirements
- a refrigerant detector located in an area where the refrigerant from a leak will concentrate
23: How many different groups of refrigerants are there?
- 15
- 3
- 7
- 11
24: 746 watts is equal to
- 1 hp
- 100 hp
- Pi
- 10 hp
25: The 522 CMR 9.00 has adopted for reference ASHRAE ____
- 10
- 15
- III
- 25