Topics: All categories in the pool
1: A tachometer is an instrument used to measure
- speed
- air velocity
- static pressure
- RPM
2: 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
3: 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
4: How far from the window does a relief valve need to be according to ASHRAE-15?
- At least 30'
- At least 40'
- At least 20'
- There is no minimum for relief valve and windows.
5: The first step in mechanical refrigeration is
- expansion
- compression
- evaporation
- condensation
6: In a low temperature refrigeration system, the benefit of the system using P.A.G. oil is
- it is hydroscopic
- it traps moisture
- viscosity
- all of the above
7: Pressure vessels with an internal volume of 3 cubic feet or less
- do not need pressure relief protection
- shall use fusible plugs
- shall use pressure relief devices or fusible plugs
- shall use pressure relief devices
8: An electrical circuit has a 208V power supply and draws 47 amps total, What would be the wattage of the circuit
- 9.776 watts
- 977.6 watts
- .9776 watts
- 9,776 watts
9: The color code of a tank of ammonia is
- white
- lavender
- silver
- light green
10: Class 3 refrigerants are
- non-flammable
- toxic
- highly flammable
- non-toxic
11: A positive displacement compressor is
- where the compressor's suction pressure and the compressor;s discharge pressure is more than 50 PSI
- a compressor in which the increase in pressure is attained by changing the internal volume of the compression chamber
- is a reciprocating type compressor with 2 or more pistons
- a compressor in which the increase in pressure is attained by changing the internal pressure of the compression chamber
12: How many flammability classifications are refrigerants in?
- 5
- 3
- 2
- 7
13: The reversing valve is commonly used
- on commercial system that involve two different temperatures
- when the code requires a check valve
- on all heat pumps
- on multiple compressor systems
14: Heat is a form of
- power
- matter
- work
- energy
15: The location of the thermal bulb for the TXV on the evaporator effects
- both the pressure and temperature in the feeler bulb
- the amount of superheat required to operate the TXV
- the amount of liquid in the evaporator
- the amount of gas in the evaporator
16: Booster compressors, pump refrigerant into the
- receiver
- heat & plate heat exchanges
- low side of the primary compressor
- high side of the secondary compressor
17: Walls and doors of a machinery room shall be at least _____ hour(s) fire rated.
- 2
- 1
- 5
- 3
18: Ammonia systems use ____ pressure to adjust oil pressure
- discharge
- air
- liquid
- stream
19: A crankcase heater has a supplied voltage of 100 volts and is drawing 1.4 amps. What is the resistance?
- 71 ohms
- 27 ohms
- 80 ohms
- 104 ohms
20: Refrigerant restricted in 2004 but used for transition for decades:
- R-11
- R-123
- R-134A
- R-22
21: Joints in piping for refrigeration containing parts must withstand temperatures of ___?
- 800F
- 1000F
- 600F
- 700F
22: Lithium-bromide, Li-Br, is best characterized as a
- sugar
- salt
- sand
- soil
23: When must refrigeration system covered by the code be inspected?
- Annually
- Annually and when installed
- Upon installation
- Not required
24: 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
25: A class B1 refrigerant is considered
- non-toxic but highly flammable
- toxic and somewhat flammable
- non-toxic and non-flammable
- toxic but non-flammable