Topics: All categories in the pool
1: Ammonia vaporization takes place at what temperature?
- -110F
- -28F
- -32F
- -460F
2: In a horizontal shell & tube condenser, the ammonia is liquefied by
- removing the latent heat of vaporization
- removing the latent heat of fusion
- passing thru the tubes from top to bottom
- water sprayed over condenser
3: A check valve is a device
- designed to allow the flow of refrigerant gas in both directions
- that is always spring loaded
- with a pressure drop
- found on high pressure steam systems
4: Pressure vessels with an internal volume of 3 cubic feet or more
- shall use fusible plugs
- shall use pressure relief devices
- shall use pressure relief devices or fusible plugs
- do not need pressure relief protection
5: R-12. R-22, and R-40 are considered Group I refrigerants.
- True
- False
6: What refrigerant doesn't have to be classifted?
- R-711
- R-134a
- R-717
- R-718
7: High pressure controls should be set no higher than
- 25% of set point
- 10% of set point
- 90% of set point
- 80% of set point
8: The test pressure applied to the high side of each factory-assembled refrigerating system shall be at least equal to the design pressure of
- the high side
- 2.5 times the design pressure
- the aggregate of the high side and low side
- the low side
9: What type of oil is used in R-410A systems?
- mineral oil
- naphthene
- polyolester (POE)
- polyalkylene glycol (PAG)
10: To determine the pump size needed for an open cooling tower system, the following must be known,
- GPM and unbalanced head and friction head
- GPM and balanced head and friction head
- GPM, pipe size, and equivalent head.
- GPM and friction head
11: The start winding has _____ turns than the run winding.
- more
- less
- the same
- none of the above
12: Each machinery room shall contain
- high and low pressure controls
- a refrigerant detector located in an area where the refrigerant 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 toxicity detector where the presence of ammonia or lithium bromide from a leak will concentrate
13: Ammonia is under what safety classification?
- A3
- B2
- B3
- B1
14: Name a reason that does not cause reduced condenser air quantity
- High ambient temperature
- Dirty fan blades
- Dirty Coil
- Prevailing winds
15: "R" represents ___ in the Ohm's law formula
- amperage
- voltage
- capacitance
- resistance
16: If a liquid receiver is designed to receive the refrigerant charge during a pumpdown procedure, it shall have the capacity to
- hold up to 110% of the pumpdown charge
- receive the pumpdown charge
- Pumpdown procedures are not allowed with systems containing liquid recievers
- release the charge when the pressure exceeds 310 psig or higher
17: What do you need to do when you install a new system?
- Document the superheat and subcooling reading
- Add refrigerant
- Insulate the suction line before you take a superheat reading
- Have it inspected
18: Sensible heat is the heat added to a substance to
- freeze it
- change its state
- raise its temperature
- cause evaporation
19: What type of fuses must be used on a HVAC system?
- TR Type, Duel Element, Time Delay
- Fast blow
- 10% lower than RLA
- none of the above
20: Insurance companies shall forward each inspection report of all refrigeration or A/C systems to the Chief of Inspections within
- 2 months
- 14 days
- 1 week
- 30 days
21: What is Absolute Zero?
- -640F
- -773F
- -400F
- -460F
22: Where is the high-side float located on a chiller system?
- liquid line
- flash line
- discharge line
- inside the chiller barrel
23: How many flammability classifications are refrigerants in?
- 3
- 7
- 2
- 5
24: Which is the lowest vacuum?
- 5" hg
- 10 psia
- 1,000 Microns
- 5 psig
25: A plug containing an alloy that will melt at a specific temperature to relief pressure is a
- fusible plug
- relief plug
- fusion plug
- rupture plug