Topics: All categories in the pool
1: Pressure vessels with an internal volume of 3 cubic feet or more
- shall use fusible plugs
- shall use pressure relief devices
- shall use pressure relief devices or fusible plugs
- do not need pressure relief protection
2: A chiller entering and leaving temperature difference is?
- 20 degrees F
- 10 degrees F
- 50 degrees F
- 5 degrees F
3: In an air conditioning plant which an indirect low side, water is used inside of bring: the proper sequence of operating the plan is
- reset the safety valve
- start the comrpessor
- reset the expansion valve
- start the fan and circulating pump
4: A pressure relief should be located at least _______ from windows and doors.
- 15'
- 20'
- 30'
- 25'
5: A person holding a license as a refrigeration technician may connect or disconnect for the purpose of installation, repair, or replacement, any electrical device or control to be a part of a refrigeration or air conditioning system, from the
- load-side of the contactor in
- 24 volt secondary side of the Class 2 transformer to the thermostat
- first disconnect in
- breaker panel in
6: The two basic types of evaporators are
- direct expansion and plate
- finned and plate
- prime surface and finned
- flooded and direct expansion
7: How many different groups of refrigerants are there?
- 3
- 15
- 7
- 11
8: At higher altitudes, boiling temperatures
- decrease
- increase
- depends on the refrigerant
- are unaffected
9: R-22 falls under which safety classification?
- A-2
- A-1
- B-2
- B-1
10: The External equalizer of a TXV compensates for
- pressure within the system
- pressure within the evaporator
- pressure drop across the evaporator coil
- pressure drop across the condenser coil
11: What is the refrigerant chlorodifluoromethane?
- R-22
- R-134a
- R-123
- R-12
12: Aluminum, Zinc, Magnesium, or their alloys shall not be used in contact with
- R-718
- ammonia
- methyl chloride
- trichlorotrifluoromethane
13: How many closing forces operate a thermostatic expansion valve?
- 1
- 4
- 3
- 2
14: Where are the three places that the discharge from an ammonia relief valve be piped?
- To chemical neutralizing tank only
- Underground, into drain, into mechanical room
- Atmosphere, Tank containing water, where the AHJ indicates.
- None of the above.
15: 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
16: The normal operating evaporator temperature of R-410A for air conditioning is typically
- 155F
- 158F
- 45F
- 32F
17: In designing duct work, pressure and ______ need to be considered
- length
- CFM
- duct sealant used
- all of the above
18: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
- 80%
- 75%
- 99%
- 90%
19: 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
20: A professional or office building would be considered what type of occupancy?
- business
- mercantile
- commercial
- public assembly
21: Megaohm meters can detect a ground in the
- 10,000,000 ohms or higher
- up to 1,000,000 ohms
- up to 1,000 ohms
- up to 10,000 ohms
22: All welding done on any refrigeration system or piping covered by 522 CMR 9.00 shall be performed by a according to Section IX of the ASME code
- competent welder
- licensed welder
- licensed technician
- welder qualified
23: "R" represents ___ in the Ohm's law formula
- resistance
- voltage
- amperage
- capacitance
24: Crankcase heaters are energized
- to allow easy compressor start-up
- while the compressor is running
- to prevent compressor freeze-up
- when the compressor is off
25: Liquid level gauge glasses shall have automatic closing shut off valves, except Bull's eye or reflex type.
- True
- False