Topics: All categories in the pool
1: Give an example of a secondary coolant?
- R-410A
- R-717
- R-12
- R-718
2: B3 refrigerants are considered
- toxic but non-flammable
- toxic and highly flammable
- non-toxic but flammable
- non-toxic but non-flammable
3: Who is permitted to access a refrigeration machine room?
- Contractors only
- Anyone, it's a completely safe area
- Any employee
- Authorized persons only
4: How many square inches per square foot?
- 98
- 64
- 24
- 144
5: Can you use Ammonia in industrial applications?
- No, never
- Yes, always
- When mixed with R-718
- Yes, Under certain condidtions
6: 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
7: If air is present in an absorption chilled water appliance, which of the following will most likely occur?
- System operating pressure will drop
- The Li-Br solution will become more diluted
- Rust can form
- The Li-Br solution will become more concentrated
8: If a purge unit fails on a low pressure chiller, what are the symptoms?
- low pressure chillers do not have purge units
- increased capacity
- low suction pressure
- high head pressure
9: In a system designed for sub-zero ambient temperatures, what must be added?
- Low-ambient kit
- Booster compressor
- Infrared dye for leak identification
- Nitrogen
10: Where is the high-side float located on a chiller system?
- liquid line
- discharge line
- inside the chiller barrel
- flash line
11: Booster compressors connect to the ____ side of the compressor
- low side
- liquid
- oil side
- vapor
12: What is the refrigerant dichlorodifluoromethane?
- R-123
- R-12
- R-134A
- R-22
13: What type of material can't be used on the outlet of a relief valve?
- Magnesium alloy
- PVC
- Stainless steel
- Copper
14: If the compression ratio on a centrifugal compressor rises too high, the compressor will stop pumping and make a loud sound commonly referred to as a
- purge
- splurge
- merge
- surge
15: The level of voltage caused by back electromagnetic force that opens the contacts of a potential relay in order to take the start capacitor out of the circuit is
- lift voltage
- pick up voltage
- boost voltage
- run voltage
16: Pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 33
- 50
- 18
- 22
17: If a liquid receiver is designed to receive the refrigerant charge during a pumpdown procedure, it shall have the capacity to
- Pumpdown procedures are not allowed with systems containing liquid recievers
- hold up to 110% of the pumpdown charge
- receive the pumpdown charge
- release the charge when the pressure exceeds 310 psig or higher
18: On a large centrifugal system, what meters the flow to the evaporator?
- TXV
- High side float
- Low side float
- Cap tube.
19: 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
- 455 psig, 185 psig.
- 257 psig, 77 psig
- 226 psig, 68 psig
- 365 psig, 120 psig
20: A relief valve discharge capacity is rated in
- temperature minus pounds of air per second divided by release rate squared
- PSIG
- PSIA
- Pounds of air per minute.
21: What is potential measured in?
- Ohms
- Henrys
- Volts
- Amps
22: The difference between saturated liquid and saturated vapor is
- heat
- volume
- pressure
- temperature
23: Heat that changes the physical state of a substance without effecting a change in its temperature is known as
- lost heat
- specific heat
- latent heat
- sensible heat
24: Setting a pressure relief device shall not exceed ___ of the design pressure
- 100%
- 90%
- 80%
- 75%
25: Which refrigerant class listed below is the most flammable?
- A-3
- A-1
- C-3
- B-2