Topics: All categories in the pool
1: Indirect systems using Group II refrigerants
- shall be used in refrigeration system in excess of 1,000 lbs
- shall be used in refrigeration system less than 1,000 lbs
- shall be used for mechanical equipment only
- shall have all refrigerant containing parts except piping, installed in a Class T machine room
2: In a motor, an internal overload might open if
- there's an excess current draw through the motor
- there's a direct short
- there was a high pressure refrigerant was used for a low pressure system.
- there's an open start winding
3: "R" represents ___ in the Ohm's law formula
- amperage
- voltage
- capacitance
- resistance
4: A hissing noise at the expansion valve is a good indication that
- gas is passing thru it
- nothing is passing thru
- liquid is passing thru it
- expansion valve is oversized
5: The rupture disc on a low-pressure chiller typically releases pressure at
- 15 psig
- 0 psig
- 10 psig
- 5 psig
6: R-718 is rated unlimited for refrigeration quantity contained in a system. Why?
- Because it's cheap
- Because it's a non-flammable refrigerant
- R-718 is not rated unlimited because it's a dangerous refrigerant
- Because it's water
7: Halogenated refrigerants cannot be used with what material?
- Magnesium alloy
- Stainless steel
- Aluminum
- Copper
8: No open flames are allowed in the machinery room unless?
- Approved by the installing contractor
- Approved by the authorized person
- Only when combustion air is provided from outside of the machinery room
- Never can be allowed
9: Copper and its alloys shall not be used with ammonia
- True
- False
10: The main cause of enacting the "no vending rule" of July 1st 1992 was
- global warming potential
- ozone depletion
- both a & b
- None of the above
11: What should never be used in pressure testing refrigeration systems?
- Oxygen
- Compressed air
- Nitrogen
- Both a and b
12: What is Trichlorotrifluoromethane?
- R-12
- R-113
- R-13
- R-11
13: Who is permitted to access a refrigeration machine room?
- Anyone, it's a completely safe area
- Contractors only
- Authorized persons only
- Any employee
14: Capacity control on a centrifugal compressor is accomplished by the
- post-rotational guide vanes
- slide vanes
- check valves
- pre-rotational guide vanes
15: When releasing a hydrogenated hydrocarbon refrigerant to the atmosphere, ample ventilation must be provided and
- the owner shall be informed
- no flames shall be permitted
- gas masks must be worn
- explosion precautions must be taken
16: Stop valves shall not be permitted between the system and the
- condenser
- bleed valve
- relief valve
- service valve
17: A normally operating R-410A system with a condensing temperature of 110F will have a high side pressure of around ______ psig
- 327 psig
- 365 psig
- 255 psig
- 125 psig
18: Systems containing more than 110 pounds must have stop valves located at the
- compressor suction inlet
- compressor discharge outlet
- receiver inlet and outlet
- All of the above
19: A direct system
- is one which encloses a separate body of evaporative refrigerant
- is a self-contained complete factory made and tested system
- is where the refrigerant comes in contact with the space refrigerated
- is on where brine is cooled & circulated to the space refrigerated
20: R-11 has the greatest corrosive effect on
- Magnesium
- Bronze
- Copper
- Aluminum
21: A relief valve discharge capacity is rated in
- PSIA
- PSIG
- temperature minus pounds of air per second divided by release rate squared
- Pounds of air per minute.
22: 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
23: Crankcase heaters are energized
- while the compressor is running
- to allow easy compressor start-up
- when the compressor is off
- to prevent compressor freeze-up
24: Pressure vessel having an inside diameter exceeding 6” with an internal pressure greater than 15psig shall be marked directly on or on the nameplate the letters _______________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
- “UM” and “UV”
- “U” or “UM”
- “UV”
- “UL”
25: The measurement of heat in a particular substance is
- enthalpy
- specific heat
- latent heat
- sensible heat