Topics: All categories in the pool
1: What is the minimum height refrigeration piping should be placed against walls?
- 7.25'
- Ceiling height
- 72"
- 6'
2: Ammonia systems use ____ pressure to adjust oil pressure
- stream
- air
- discharge
- liquid
3: Increasing superheat will do what to your frost line?
- Decrease
- Nothing
- Could either increase or decrease depending on the load conditions
- Increasae
4: The low pressure oil safety switch
- never trips
- resets itself automatically
- resets itself after the time delay has terminated
- must be reset manually
5: Dew point is
- the temperature of air of 50% RH
- the temperature below which water vapor in the air will start to condense
- the temperature above which water vapor in the air will start to condense
- the temperature below which water vapor in the air will start to evaporate
6: The main cause of enacting the "no vending rule" of July 1st 1992 was
- global warming potential
- ozone depletion
- both a & b
- None of the above
7: A R-410A system running with a condensing temperature of 110F and 50F evaporator temperature will read pressures of ___ on the high side and ___ on the low side
- 365 psig, 120 psig
- 455 psig, 185 psig.
- 226 psig, 68 psig
- 257 psig, 77 psig
8: A machine room with a refrigerant system using ammonia shall
- be provided with a continuously operated ventilation system
- be considered a non-hazardous location in accordance with National Electrical code
- have no flame producing apparatus permanently installed and operated
- All of the above
9: A thermometer inside a duct measures ____ heat.
- sensible
- hidden
- latent
- specific
10: Pressure relief devices are marked with a ____________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
- UV or UR
- UL and UM
- UL and UR
- UM or UL
11: Pressure vessels having design pressures of 15 psig or less shall have the strength to withstand at least ______times the design pressure.
- 2.0
- 3.0
- 2.5
- 5.5
12: Single compound Refrigerants are classified by what two criteria?
- Flammability and toxicity
- Flammability and temperature range
- Temperature range and hazardousness
- Weight and color
13: R-11 has the greatest corrosive effect on
- Copper
- Aluminum
- Bronze
- Magnesium
14: What is absolute humidity?
- the amount of moisture in the air per one pound of 50% RH air
- the amount of moisture in the air in grains of cubic feet of volume
- the amount of moisture in the air in grains of square feet of volume
- none of the above
15: A multi-evaporator refrigeration system uses what type of valve to maintain evaporating temperatures?
- EEV
- Solenoid valve
- EPR valve
- CPR valve
16: The best way to determine the voltage requirement for an electrical component is to
- determine the capacity of the service panel
- read the voltage with a mulitmeter
- check with the utility company
- read the nameplate data
17: If a low-pressure chiller has a low-side leak, which of the following will most likely result?
- Low suction pressure and low discharge pressure
- Low head pressure and high suction pressure
- High head pressure and low suction pressure
- High suction pressure and high discharge pressure.
18: Give an example of a secondary coolant?
- R-717
- R-12
- R-718
- R-410A
19: What percentage of amperage difference is allowable phase to phase on a HVAC circuit phased to phase?
- 1%
- 4%
- 2%
- 25%
20: Ammonia is under what safety classification?
- B1
- B3
- A3
- B2
21: Ammonia belongs to Group
- A-1
- B-2
- B-1
- A-2
22: What should never be used in pressure testing refrigeration systems?
- Oxygen
- Compressed air
- Nitrogen
- Both a and b
23: Pressure vessels shall be provided with ___________in accordance with Section VIII of the ASME Boiler & Pressure Vessel Code
- Pressure vessels need no type of protection as long as it is hydrostatically tested every three months
- over pressure protection
- over pressure protection as well as a temperature protection device
- over pressure protection and a rupture disc
24: One atmosphere equals
- 0 psia
- 29.4
- 14.7
- 0 psig
25: When can 50/50 solder be used?
- in the low side
- in the high side
- liquid and suction lines
- none of the above.