Topics: All categories in the pool
1: Refrigeration devices shall be equipped with a ____ to protect against unexpected pressure due to a malfunction or fire?
- Relief valve
- T&P device
- Temperature limiter device
- Circuit Breaker
2: If the suction pressure is low and the evaporator temperature high, the cause will be a?
- overcharged
- compressor suction valve stuck open
- too small evaporator
- starved evaporator
3: The low pressure oil safety switch
- never trips
- must be reset manually
- resets itself automatically
- resets itself after the time delay has terminated
4: _____ alloys shall not be used in contact with an halogenated refrigerants.
- Zinc
- Nickel
- Magnesium
- Copper
5: An azeotropic refrigerant is
- a mixture of two or more refrigerants that boil at about the same temperature minimizing temperature glide.
- a mixture of two or more refrigerants that boil at much different temperatures causing temperature glide
- a mixture of two or more refrigerants that boil at much different temperatures minimizing temperature glide
- none of the above
6: Foaming of oil in a compressor is most likely to occur
- when ambient temperature are low
- at start-up
- when there is insufficient air across the condenser(i.e., dirty coil)
- when the evaporator temperatures are below 32F
7: Pressure limiting devices are not required for systems containing less then ________ refrigerants.
- 22 lbs
- 6.6 lbs
- 13.9 lbs
- 44 lbs
8: Sensible heat is the heat added to a substance to
- change its state
- cause evaporation
- raise its temperature
- freeze it
9: When an inspection is needed, how often must it be done?
- every 18 months
- annually
- every 24 months
- every 36 months
10: A chiller entering and leaving temperature difference is?
- 5 degrees F
- 20 degrees F
- 10 degrees F
- 50 degrees F
11: The Board of Boilers adopts by reference
- MSCA Code
- Montreal Protocol Safety Code
- the MACS Pressure Vessel Code of Massachusetts
- the 1997 ANSI/ASHRAE Safety Code
12: If the power element on an expansion valve should lose its charge, the valve would
- Under feed
- Over feed
- Close
- Stay open
13: The purpose of an accumulator is to
- store excess refrigerant from the reciver
- reduce friction loss to the flow of refrigerant
- assure no liquid returns to the compressor
- filter out impurities from the system
14: How many forces operate a thermostatic expansion valve?
- 4
- 1
- 2
- 3
15: Machinery rooms shall be vented to _____________ and utilizing mechanical ventilation.
- the outdoors
- Machinery rooms need not be vented
- the return air ducted system
- the mechanical room housing the refrigeration system
16: "P" represents ______ in the Watt's law formula
- watts
- amperage
- reactance
- voltage
17: How far from the ground does a relief valve need to be?
- At least 25' above grade
- At least 20' above grade
- Not more than 3' above grade
- At least 15' above grade
18: Which refrigerant is lighter than air?
- R-717
- R-11
- R-123
- R-134a
19: An evaporator coil located near heating coil shall have a pressure-relief device installed within ______ inches of the evaporator.
- 48
- 36
- 18
- 24
20: Group A3 refrigerants have a ______ flammability rating than Group B1 refrigerants
- there is no Group B1 refrigerants
- the same
- higher
- lower
21: Heat is a form of
- energy
- work
- matter
- power
22: High side floats are used on centrifugal chiller systems are are considered critically charged systems.
- False
- are obsolete.
- True
- depends on the type of refrigerant being used
23: What type of voltage cause a potential relay to open?
- 24 volt supply from the thermostat
- 120 volt line voltage
- Pick-up voltage
- none of the above
24: In a properly balanced system with valves open and properly adjusted, if the suction line is warm to the touch, its because of
- moisture in the system
- oil in evaporator
- low head pressure
- not enough oil in the system
25: A restaurant is classified as a
- mixed occupancy
- public assembly occupancy
- large mercantile occupancy
- commercial occupancy