Topics: All categories in the pool
1: Can a R22 line set be reused for a 410A system and if it can be reused, what must be done to it?
- Flush with R-718
- Flush with ammonia
- Flush with RX-11
- Flush with R-11
2: Aluminum, Zinc, Magnesium, or their alloys shall not be used in contact with
- trichlorotrifluoromethane
- R-718
- methyl chloride
- ammonia
3: Where is an EPR valve located on a multi-evaporator system?
- Suction line of the warmest evaporator
- Suction line prior to the accumulator of the lowest temperature system
- Suction line at the compressor
- Suction line of the coolest evaporator
4: What is a Category "D" fluid?
- A typical refrigerant used on newer air conditioning and heat pump ssytems
- A toxic fluid, which can produce serious irreversible harm to persons on breathing or bodily contact
- Any fluid that exceeds 150 psig and has design temperature of over 366F
- A fluid which is nonflammable, nontoxic, not damaging to human tissues, does not exceed 150 psig, and design temperature is between -20F to 366F
5: All serviceable components of a refrigeration system shall be provided with
- service manuals
- name plates with markings referring to pressure and temperature in accordance with ASME Boiler and Pressure Vessel Code
- safe access
- manufactures instructions on start-up procedures
6: What is the purpose of a surge capacitor on a contactor?
- to protect low voltage equipment
- to provide smoother start/stops
- to balance the sine waves
- to keep the contactor pulled in
7: A halide torch is most useful with a freon compression system
- to release a sticking valve
- to sweat flanges on the refrigeration piping
- to remove from from TXV's and evaporator coils
- to detect refrigeration leaks in piping joints
8: What refrigerant doesn't have to be classifted?
- R-711
- R-717
- R-134a
- R-718
9: What is a high-side float?
- An electronic-type metering device that contains a float assembly within the device which can accurately meter refrigerant into the evaporator as the load varies
- Located in the liquid line entering the evaporator, so when the refrigerant level is higher in the liquid line than the evaporator, the float rises to allow more refrigerant flow into the evaporator
- Located in the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the low side of the chiller
- Located in the liquid line entering the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the high side of the chiller
10: A micron is
- one thousandths of a millimeter
- one millonths of a centimeter
- a larger unit of measurement than Hg
- one millonths of a micrometer
11: How many different groups of refrigerants are there?
- 7
- 3
- 11
- 15
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
- 226 psig, 68 psig
- 257 psig, 77 psig
- 455 psig, 185 psig.
- 365 psig, 120 psig
13: R-11 belongs to Group
- B-1
- B-3
- A-1
- A-2
14: What type of voltage causes the winding in a potential relay to open?
- BEMF (Back Electro-Motive Force)
- 24V control voltage from the thermostat
- 120V line voltage
- None of the above
15: A premise or that portion of a premise where people transact business, receive personal service, or purchase foods, other goods is considered a
- mercantile occupancy
- business occupancy
- public assembly occupancy.
- commercial occupancy
16: A compressor that increases vapor pressure by changing the internal volume of the compression chamber is called?
- Pressure induced displacement.
- Positive displacement
- Non-positive displacement
- Low Pressure displacement
17: A class B1 refrigerant is considered
- non-toxic and non-flammable
- non-toxic but highly flammable
- toxic and somewhat flammable
- toxic but non-flammable
18: What is the refrigerant chlorodifluoromethane?
- R-134a
- R-12
- R-22
- R-123
19: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
- 330 lbs.
- 550 lbs
- 660 lbs
- 55 lbs
20: If the dry bulb temperature is 85F and the wet bulb temperature is 70F, the dew point temperature will be approximately (use psychometric chart)
- 77F
- 70F
- 32F
- 58F
21: How can you test mechanical strength of an electrical connection?
- measure ohms with an electrical meter
- measure voltage across the connection
- attempt to pull the wire from the connector by hand
- none of the above.
22: What is the minimum size of the discharge pipe?
- Same size as the outlet of the relief valve
- One pipe size larger that the inlet of the relief valve
- Depends on size of manifold
- All of the above
23: 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
24: 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
- 100
- 550
- 350
25: What happens to copper joints when overheated?
- nothing
- joint becomes oxidized and ditorted
- copper becomes harder
- none of the above