NFPA 780 LPI 175 Review Questions

  1. Materials used on an LPS must be?
    Listed or labeled
  2. A class I structure is 75 feet or lower True or False?
  3. What is the weight of Class I Aluminum Conductor?
  4. What is the weight of Class I copper conductor?
  5. What is the weight per length of Class II copper conductor?
  6. What is weight per length of Class II aluminum conductor?
  7. What is the minimum diameter of solid copper Class II air terminals?
    1/2 inch
  8. What is the minimum diameter of Class II solid aluminum air terminal?
    5/8 inch
  9. What is minimum diameter of solid copper Class I air terminals?
    3/8 inch
  10. What is the minimum diameter of solid aluminum Class I air terminal?
    1/2 inch
  11. What is the minimum diameter of Class II tubular copper or aluminum air terminals?
    None, not allowed
  12. What is minimum diameter of Class I tubular Copper or aluminum air terminals?
    5/8 inch
  13. What is the minimum width of copper aluminum bonding plates?
  14. What is the height of a Class II structure?
    Higher than 75 feet.
  15. When a section of a structure e.g. a steeple exceeds only that portion above 75 feet must use class II hardware?
    True or False
  16. What is the minimum height above the object it protects must an air terminal must be ?
    10 inches
  17. A Heavy duty stack has the following height and opening size:
    Higher than 75ft and 500 square inches.
  18. An air terminal that is 36 inches tall needs intermediate support at 18 inches?
    True or False ?
  19. The maximum distance of an air terminal from the edge of a roof is how many feet?
    2 feet
  20. The maximum spacing of air terminals 24 inches tall or less along the edge of a roof is how many feet?
    20 feet
  21. The maximum spacing of air terminals taller than 24 inches along the edge of the roof is how many feet?
    25 feet
  22. The maximum distance of air terminals located within the roof parameter of a flat or gently sloping roof is how many feet?
    50 feet
  23. What slope is required for a roof 40 feet or less wide to be considered a pitched roof?
  24. What slope is required for a roof > 40 feet wide to be considered a pitched roof?
  25. No parameter strike termination devices are required on pitched roofs where the eave is 50 feet or less.
    True or False
  26. What is the maximum distance between intermediate air terminal on ridged roofs?
    50 feet
  27. For flat or gently sloping roofs, what is the maximum distance from a main parameter or down conductor that a cross connection conductor can be located?
    150 Feet
  28. What is the maximum distance from the edge of a roof projection that an air terminal can be located?
    2 feet
  29. Conductors shall be connected together with what what type of connectors?
    Tee, Wye, end to end
  30. Air terminals on chimney or HVAC units must be installed so no edge is more than 3 feet from the air terminal?
    True or False
    False, 2 feet maximum.
  31. Air terminals or devices(chimney, HVAC, etc.) used as air terminals must be connected with how many main conductors to ground?
  32. What thickness of metal must a device be to act as an air terminal or main conductor?
    3/16 inch
  33. Metal roof top units can have the air terminals installed by:
    • 1. adhesive bases
    • 2. metal bases with at least 3 square inches metal to metal contact.
    • 3. Metal bases connected to the frame with drill and tapped 1/2" bolt with 5 threads fully engaged.
  34. What minimum thickness of metal must the enclosure of metal enclosed roof top unit be to act as a down conductor?
    0.064 inches
  35. If a metal enclosed roof top unit is used as the down conductor or air terminal how must it be connected to the main conductor?
    • 1. Connected at the base at two points as far away from each other as possible.
    • 2. Each connector must make 3 square inches metal to metal contact.
  36. buildings 25 feet or lower can have a zone of protection with a slope of:
  37. Buildings taller than 25 feet but not exceeding 50 feet can have a zone of protection with a slope of:
  38. The rolling sphere method normally uses a sphere with a radius of:
    150 feet
  39. The rolling sphere radius used for structures housing explosives is:
    100 Feet
  40. The formula for calculating the distance protected by a rolling sphere from one level to another is:
  41. How many paths to the grounding electrode must an air terminal have?
  42. What is the maximum length of main grounding conductor interconnecting one roof level to another before 2 paths to the grounding electrode are required?
    40 Feet
  43. The maximum horizontal length of a dead-end conductor from an air terminal to a main conductor located at the same level is:
    8 feet
  44. The maximum length of a dead-end conductor from an air terminal to a main conductor located a level below the level of the air terminal is?
    16 feet
  45. All dead end conductors must run a horizontal and upward direction.
    True or False
    False, run must be horizontal and downward.
  46. Permanent handrails and ladders subject to lightning can be used as down conductor if their thickness is a minimum of:
    .064 inches
  47. Main conductors shall be run in _______ and ______ avoiding to make _____ pockets and ______ Pockets.
    horizontal, down-ward U, V
  48. The minimum radius of bends on main conductors is:
    8 inches
  49. conductors must be protected with ____ or ____ when within ____ of the top of a chimney or stack producing corrosive vapors.
    Tin, lead, 24 inches
  50. Copper must not run off into aluminum.
    True or False
  51. Aluminum conductors must not be within _____ of the ground/earth.
    18 inches
  52. Down conductor must be protected from damage for _____ above the ground.
    6 feet
  53. Moveable metal objects must be bonded to the LPS with main conductor making metal to metal contact of _______ or _______ for rounded surfaces.
    3 sq inches, 1 1/2"
  54. Cross run conductors connecting intermediate air terminals shall connected to parameter main conductor at intervals not exceeding ______.
    150 feet
  55. Each structure must have at least ______ down conductors.
  56. Structures with parameter exceeding _____ must have down conductors no more then _____ apart.
    250ft, 100ft
  57. Flat or gently sloping roofs must have down conductors every _____.
  58. Structures with roof 50ft to 100ft wide must have at least ____ cross conductor(s).
  59. Structures with roofs 100 to 150 feet wide must have at least ______ cross conductors.
  60. Metal siding or roof material less than 3/16" thick may be used as a main or down conductor.
    True or False
    False, must be at least 3/16" thick
  61. exposed conductors must be fastened to the structure every ____.
    3 feet
  62. conductors coursed through the air must not exceed ______ without support.
    3 feet
  63. Ground rods must be ______ diameter and ______ long
    1/2", 8 feet
  64. How deep must ground rods be driven?
    10 feet
  65. Ground rods must be made of what materials?
    Copper, copper clad steel, stainless steel
  66. Fittings at Tee, Wye and end to end connections must be capable of withstanding ______ pulling force.
  67. Tee, wye and end to end connectors shall be made with ________________________ connections
    Bolted, welded, brazing, compression
  68. Connection of the down conductor to the grounding electrode must be by_______________connections
    Bolted, welded, brazing or high compression
  69. Crimp type connections can be made on Class II systems.
    True or False
  70. At what distance must ground rods be seperated from each other?
    The sum of the length of the ground rods or sum of burial depths.
  71. What is the thickness and area of a ground plate?
    0.32in and 2 sqft
  72. How deep must a ground plate be buried?
    18 inches minimum
  73. A concrete encased electrode is ______ of main conductor encased by ______ of concrete.
    20 feet, 2"
  74. What is the minimum length and diameter of rebar in concrete that can be considered a concrete encased electrode?
    20 feet and 1/2"
  75. Down conductors entering corrosive soil must be protected for a distance of _______ with a a covering against the corrosive.
    3 feet above grade.
  76. What materials can be used to protect down conductors?
    Wood platic or metal
  77. Down conductors on steel reinforced concrete shall be bonded to the steel on the _____ and _____. For long runs bonding must occur every ______.
    Top,bottom, 200 feet
  78. Disconnects to the grounding electrode should be made at low as possible to limit false ground resistance reading.
    True or False
  79. LPS grounding electrode system can be any system e.g. power, communication etc.
    True or False
    False, it must be dedicated to the LPS.
  80. The connection to the LPS grounding electrode system must be made at least_______ from the base of the building and ______ below grade.
    2 feet,  1 foot
  81. How much electrical contact must there be on connections to ground rods?
    1 1/2"
  82. How many bolts must be used to make connections to ground rods?
  83. What size conductor on a class II system must the ground ring be?
    The same size as the class II main conductor.
  84. How deep must a ground ring be buried?
    18 inches
  85. How deep must a ground plate be buried?
    18 inches
  86. Roofs with a Width width of 50 to 100 feet must have at least _____ cross conductor
  87. Roof with a width of 100 to 150 feet must have at least ______ cross conductors.
  88. Metal piping within ______ of a building shall be interconnected.
    25 ft
  89. Buried metallic conductors and grounded media with in ______ vertically must be interconnected
    12 feet
  90. Connections to the metal frame of a building must have a contact area of at least _______.
    8 sq inches
  91. Copper or copper alloy materials within _______ of the top of a Heavy duty stack shall be protected with at least _____ thick lead.
    • 25 feet
    • 1/16"
  92. Aluminum may be used on a heavy duty stack?
    True or False
  93. Air terminals on a heavy duty stack shall be ______ diameter and no less than _______tall and no more than ______ tall.
    • 5/8"
    • 18"
    • 30"
  94. Air terminals on heavy duty stacks shall be made of: _______, ________, ________, or _______
    • Solid Copper
    • Stainless steel
    • Titanium
    • Monel metal
  95. Down conductors on heavy duty stacks shall be protected within ________ of the ground.
    8 feet
  96. Air terminals on Heavy duty stacks shall be space no more than ______ from each other and no more than _______ from the edge of the stack.
    • 8 ft
    • 2 ft
  97. Conductors on heavy duty stack shall be supported every ________ horizontally and ________vertically
    • 2 feet
    • 4 feet
  98. Threaded shank fasteners shall be ______ for air terminals and ______ for conductors
    • 1/2"
    • 3/8"
  99. Connections of roof cable conductor to structural steel used as downleads must be made by connectors with a minimum of 3 square inches of contact area.
    True or False
    False must be 8 square inches.
  100. Only 1 air terminal must be mounted to a chimney if located with 24 inches of all outside corners. In no case, shall downleads be spaced closer than 100 feet.
    True or False
    False down leads can be closer then 100 feet apart but must not exceed 100 feet apart.
  101. Any properly grounded structural steel framing member (beam or column) which is 1/4" thick, would qualify as a substitute for a main cable conductor.
    True or False
    True min. is 3/16"
  102. All metal guy wires for protected chimneys and vents must be connected to the lighting protection system at their top and bottom.
    True or False
  103. A 60 foot tall flat roof building is classified as:

    B. Class I Structure
  104. Class II solid copper air terminals must be of what minimum diameter?

    B. 1/2 inch
  105. The minimum weight requirement for Class I copper conductor is:

    A. 1871/2 lbs per 1000'
  106. The minimum ground resistance specified in the standards for a lightning protection system grounding electrode is:

    D. None of the above no ground resistance value is in the standards.
  107. The material no longer allowed by NFPA for a driven grounding electrode is:

    D. Galvanized Steel
  108. Services entering a building fall into 3 categories that specifically require a surge protection device. Name the 3 systems identified by NFPA-780.
    • The three systems are:
    • Electrical
    • Communication
    • Attenna
  109. The minimum total number of air terminals required to protect a flat top mechanical unit measuring 4 feet wide x 10 feet long is:
  110. Trees are recommended to have 2 down leads when the trunk exceeds a diameter of ______ feet.
  111. The type pf metal body that must always be considered for bonding is a/an ______ metal body.
  112. At building with a height exceeding _____ requires a ground ring?

    A. 60 Feet
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NFPA 780 LPI 175 Review Questions