Topics: All categories in the pool
1: On a ammonia compressor, the pressure of a forced fed oil pump is changed by varying the
- opening at the pump outlet
- cooling temperature set-point
- adjustment of the spring tension of the TXV
- opening at the pump inlet
2: A Category D fluid
- is when the fluid handled is non flammable, nontoxic, and not damaging to human as defined in ANSI/ASME Process Piping.
- is when the design pressure does not exceed 150 psi
- a fluid for service piping in which the potential for personnel exposure is judged to cause harm and irreversible damage to those persons exposed to it
- Both a and b are correct
3: Absolute pressure is
- Gauge Pressure
- Atmospheric Pressure
- Gauge + Atmospheric Pressure + Pi
- none of the above
4: The oil separator is always inserted in the system
- where it can be easily serviced
- to prevent oil logging
- in a cool spot
- in the discharge line
5: The Board of Boilers adopts by reference
- the MACS Pressure Vessel Code of Massachusetts
- Montreal Protocol Safety Code
- MSCA Code
- the 1997 ANSI/ASHRAE Safety Code
6: What is the minimum height refrigeration piping should be placed against walls?
- 7.25'
- Ceiling height
- 6'
- 72"
7: Crankcase heaters are energized
- to prevent compressor freeze-up
- while the compressor is running
- to allow easy compressor start-up
- when the compressor is off
8: R-11 belongs to Group
- B-1
- B-3
- A-2
- A-1
9: Which refrigerant class listed below is the most flammable?
- B2
- C3
- A3
- A2
10: A rule of thumb in air conditioning is ____ CFM per ton?
- 100
- 400
- 600
- 500
11: A relief valve discharge capacity is rated in
- temperature minus pounds of air per second divided by release rate squared
- PSIA
- PSIG
- Pounds of air per minute.
12: 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.
- 226 psig, 68 psig
- 257 psig, 77 psig
- 365 psig, 120 psig
13: The high side float assembly meters refrigerant into the evaporator through the
- upper chamber of the high side
- upper chamber of the low side
- lower chamber of the high side
- lower chamber of the low side
14: If air is present in an absorption chilled water appliance, which of the following will most likely occur?
- The Li-Br solution will become more concentrated
- System operating pressure will drop
- The Li-Br solution will become more diluted
- Rust can form
15: Which of the following controllers would you expect to be most sensitive to temperature changes?
- line voltage t-stat
- immersion controller
- aquastat
- low voltage t-stat
16: 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
17: A pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 22
- 25
- 66
- 50
18: Pressure limiting devices are not required for systems containing less then ________ refrigerants.
- 22 lbs
- 44 lbs
- 6.6 lbs
- 13.9 lbs
19: What type of relief valve is used on a CO2 system?
- gate valve
- fusible plug
- glove disc
- rupture disc
20: A premise or that portion of a premise where large numbers of people congregate and from which occupants cannot quickly vacate the space such as auditoriums, ballrooms, classrooms, passenger depots, restaurants, and theaters is considered a(n)
- public assembly occupancy
- institutional occupancy
- illegal occupancy
- commercial occupancy
21: Large mercantile occupancy is
- a premise or that portion of a premise where more than 1500 persons congregate on levels above or below street level to purchase personal merchandise
- a premise of that portion of a premise where more than 100 persons congregate on levels above of below street level to purchase personal merchandise.
- a premise of that portion of a premise where more than 50 persons congregate on levels above of below street level to purchase personal merchandise.
- a premise or that portion of a premise where more than 200 persons congregate on levels above or below street level to purchase personal merchandise
22: Increasing superheat will do what to your system?
- Nothing
- Increase gas flow
- Increase liquid flow
- Decrease liquid flow
23: A single pole-double throw switch uses how many wires?(excluding the ground)
- 3
- 2
- 4
- 5
24: The measurement of heat in a particular substance is
- specific heat
- latent heat
- sensible heat
- enthalpy
25: Joints in piping for refrigeration containing parts must withstand temperatures of ___?
- 600F
- 1000F
- 700F
- 800F