Topics: All categories in the pool
1: Whoever owns/uses a refrigeration or air conditioning system covered by this code
- must notify the Department of Public Safety prior to starting the system
- shall be licensed by the Commonwealth of Massachusetts according to CMR 522
- shall make application for inspections to the Chief of Inspectors
- None of the above
2: Brazed joints melt at temperatures above
- 1,000F
- 500F
- 1,200F
- 800F
3: Calculate the voltage in a series circuit when the total amperage is 10 amps and the resistors have values of: R1=12 ohms, R2=8 ohms, R3=4 ohms
- 240 volts
- 2.40 volts
- 2,400 volts
- 24.0 volts
4: Which refrigerant is lighter than air?
- R-717
- R-11
- R-123
- R-134a
5: A premise or that portion of a premise where people transact business, receive personal service, or purchase foods, other goods is considered a
- public assembly occupancy.
- mercantile occupancy
- business occupancy
- commercial occupancy
6: Capacity control on a centrifugal compressor is accomplished by the
- post-rotational guide vanes
- slide vanes
- pre-rotational guide vanes
- check valves
7: copper and its alloys shall not be used in contact with _____ except as a component of bronze alloys for bearing or other non-refrigerant containing uses.
- Lithium bromide
- ammonia
- HCFC-123
- CFC-11
8: A restaurant is classified as a
- commercial occupancy
- mixed occupancy
- large mercantile occupancy
- public assembly occupancy
9: A secondary coolant is defined as
- any refrigerant direcly in contact with the cooling space for process cooling
- a low temperature refrigerant used for cascading systems
- any liquid used for the transmission of heat without a change of state in A/C refrigeration systems having flash point above 150F
- a combination of interconnected parts from a closed circuit in where fluid is circulated for the purpose of cooling for a refrigeration system.
10: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
- Nothing must be done
- Place sign, check for leaks, and insulate suction line
- Make sure its compatible, notify owner, and notify AHJ.
- you can never change refrigerants
11: The actual expansion curve of compressor follows most nearly which one of the following
- Isothermal
- Pressure-Temperature
- Volume
- Adiabatic
12: The measurement of heat in a particular substance is
- sensible heat
- enthalpy
- latent heat
- specific heat
13: Increasing superheat will do what to your frost line?
- Could either increase or decrease depending on the load conditions
- Increasae
- Decrease
- Nothing
14: Foaming of oil in a compressor is most likely to occur
- when the evaporator temperatures are below 32F
- when there is insufficient air across the condenser(i.e., dirty coil)
- at start-up
- when ambient temperature are low
15: A total of all group A-2,B-2, A-3, and B-3 refrigerants shall not exceed ____ lb in the occupied areas and machinery rooms of institutional occupancies.
- 50
- 550
- 350
- 100
16: Refrigerants shall be classified by
- toxicity and flammability
- color codes
- maximum permissible quantities of each group
- requirements for commercial, industrial, and residential occupancies
17: Heat cannot of itself, pass from a
- cold to a warmer body
- warm to a colder body
- state of hot energy to a state of cold energy
- None of the above
18: The two basic types of evaporators are
- flooded and direct expansion
- prime surface and finned
- direct expansion and plate
- finned and plate
19: The rupture disc on a low-pressure chiller typically releases pressure at
- 0 psig
- 5 psig
- 15 psig
- 10 psig
20: In a motor, an internal overload might open if
- there's an excess current draw through the motor
- there was a high pressure refrigerant was used for a low pressure system.
- there's an open start winding
- there's a direct short
21: Name an HCFC refrigerant(s):
- R-22
- R-123
- R-11
- both a & b
22: It shall be the duty of the person in charge of the premises on which a refrigeration system containing more than ___ lbs of refrigerant is installed to provide a schematic drawing or panel giving directions for the operation of the system.
- 75
- 50
- 55
- 15
23: If your suction line is warmer than the room temperature, this may indicate
- an over charge
- plugged air filter
- below normal superheat
- a low charge
24: The high side float assembly meters refrigerant into the evaporator through the
- lower chamber of the low side
- upper chamber of the high side
- lower chamber of the high side
- upper chamber of the low side
25: Sublimation occurs when
- gas is formed directly from a solid
- ice melts and turns to water
- gas is formed from a liquid
- liquid is formed from a gas