grounding&bonding1.txt

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grounding&bonding1.txt
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grounding bonding electrical
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grounding and bonding: reference Soares book on Grounding and Bonding 2008
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  1. The Equipment Grounding Conductor provides a path to the service ground in case of what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    Ground fault.
  2. Low impedance ground means what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    Low opposition to current.
  3. The correct term for opposition to current in an ac system is? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 11
    Impedance.
  4. What is the name given to the opposition to current offered by the internal structure of the conductive material? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 12
    Resistance.
  5. Grounding of a system or metal objects is referred to as __________? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 12
    Earthing.
  6. Current takes all paths or the path of least resistance? IAEI, Soares Book on Grounding and Bonding(notecard set g&b1), PP 12
    All paths.
  7. What path must be available for current to exist? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP13
    A complete path
  8. The grounding safety circuit must meet 3 criteria. What are they? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 14
    • 1.Continuous path
    • 2.Adequate capacity for fault
    • 3.Be of low impedance
  9. What term defines: the more current through an ocpd the quicker it acts. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 14
    Inverse Time
  10. The grounding of the grounded conductor of a system is accomplished how? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 15
    by a connection to ground through a grounding electrode conductor either at the service or at a separately derived system.
  11. The grounded conductor is used only on what side of the service grounding connection? Why? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 15
    Line. Because connection on the load side creates multiple paths for grounded current and can energize equipment and conduits
  12. The difference between the term main bonding jumper and system bonding jumper is what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 15

    Because of the word and in the definition, what would be the main bonding jumper in a main panel? IAEI, Soares Book on Grounding and Bonding (notecard set g&b1)
    The main bonding jumper connects the grounded service conductor to the equipment grounding conductor and the service enclosure, whereas the system bonding jumper does the same at separately derived services.

    A hook shaped piece of metal bonding the can to the grounding bar, identified by a green screw.
  13. Desensitizing the GFP device occurs when what happens? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 18
    Multiple paths for current are available.
  14. A conductive path from the point of a ground fault though the normally non-current carrying part of an electrical system to the electrical supply source is best described as a?
    A. Ground-fault current path
    B. Ground Fault
    C. Grounded, Solidly
    D. Effective Ground-Fault Current Path
    ANSWER: A. Ground Fault current path.  Note: an effective ground fault current path would be low-impedence. 
  15. What is the difference between the term effective ground-fault current path and ground fault current path? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 19
    Effective means intentional and path means electrically conductive. A ground fault is unintentional.
  16. Isolated versus guarded means what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 20
    Isolated means not readily accessible; whereas guarded is.
  17. What is permitted to be used as a substitute for grounding? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 20
    Double insulation
  18. Anything grounded is? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    forced to take the same potential as Earth
  19. Where the ungrounded system conductors are installed in grounded metal raceways or enclosures, the ungrounded system becomes? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 23
    Capacitively coupled to ground
  20. The severity of electric shock is related to four elements? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    • 1.amount of current
    • 2.duration of exposure
    • 3.path
    • 4.frequency
  21. Three types of electrical burns exist. They are ____________? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 24
    • Electrical
    • Arc
    • Thermal contact
  22. Where the electrical system is not grounded, the electrical equipment is? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    Connected to earth at the service and bonded
  23. Dairy cattle are so sensitive to electricity that a potential of as little as _______ volts between conductive portions of floors, walls, piping and stanchions caused behavior problems that resulted in lost production. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 25
    2 volts
  24. The phrase likely to become energized is included in Annex B of the NEC Style Manual as a standard term meaning _______________. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 1 & 27

    Insulation failure can result in two kinds of faults. What are they? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 28
    Failure of insulation on

    Line to line or line to ground
  25. The measurement of insulation resistance is usually what form of electricity and between how many volts on under 600 volt systems with what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    DC, 500 to a 1000, and with a meger
  26. A high voltage dielectric test is often called? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 29
    Hi-pot test
  27. A grounded system conductor, such as a neutral conductor, that is not generally considered to be grounded again past the service disconnecting means can be considered what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 30
    Ground fault
  28. A conductor's long time rating can be thought of as ampacity where its short time rating can be thought of as its __________ rating. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 32
    Withstanding
  29. Where a delta-connected high voltage system is used to supply portable or mobile equipment, a system neutral shall be derived. This is usually accomplished by means of a(an)? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 40
    Zigzag grounding transformer
  30. AC systems over ________ volts are permitted but not required to be grounded. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 40
    1000
  31. Examples of separately derived systems include? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    • Generator systems with no neutral connection to the utility
    • Transformers with no primary to secondary connection
    • Rectified power
    • Inverters and batteries for uninterruptible power systems
    • PV
  32. A High impedance grounded system has all the advantages and non of the disadvantages of an ___________ and is used where facility operation cannot be halted. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    ungrounded system
  33. Examples of systems that are not separately derived include. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 41
    • Autotransformers
    • Generators not connected to a transfer switch, which switches all conductors at once
  34. Typical ungrounded systems always use what type of transformer? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    Delta
  35. When an ungrounded system with one ground fault experiences a second ground fault on a different phase, the result is a _____________ on the system. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 43
    Phase to phase fault
  36. In 600 volt systems, the two greatest source of capacitance to ground are? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 45
    Conductors in metal conduit and windings
  37. Capacitance to ground is known as? Versus current from conductors to ground? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    Leakage capacitance versus leakage current or charging current.
  38. Disadvantages of an ungrounded system are? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    • Power system over voltages
    • Transient over voltages
    • System voltages above ground are not necessarily balanced or controlled
    • Destructive arcing
  39. Not all grounded conductors of a system are? What is one example? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 54

    Are all nuetrals grounded conductors?
    • Neutrals
    • For example, a ground phase conductor of a three-phase, three-wire, delta connected system is a grounded phase conductor, not a neutral of the system

    Yes
  40. Grounded conductor identification for MI cable is located where? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 55
    At its terminations
  41. The following grounded systems are usually grounded in what manner? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 57
    Low voltage (under 600v)
    Medium voltage (2.4-15KV)
    High voltage systems (34.5KV and up)
    IAEI,
    • Low voltage: almost always solidly or high impedance grounded.
    • Medium voltage: either solidly or resistance (low or high resistance PP 361) grounded.
    • High voltage: grounded through surge arresters or ungrounded
  42. Where three transformers that have center taps are connected in a delta bank, How many transformer(s) may have thier midpoint grounded? Why? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 57
    One

    Since there is a difference in potential between the midpoints of each transformer and will create a short.
  43. High leg voltage to ground (b phase) equals what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    total of phase to phase voltage x 1.732 pp.58
  44. Where an ac system operating at less than 1000 volts is grounded at any point, the grounded conductor shall be run to what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 67
    Each service disconnecting means
  45. Table 250.66 and T250.122 generally refer to what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 71
    • T250.66 - The service overcurrent device
    • T250.122 - Beyond the service overcurrent device.
  46. The minimum size of the grounded service conductor that must be run to the service disconnecting means is based on what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 71
    Based on the size of the ungrounded service entrance conductors, and not on the service circuit breakers or fuses.
  47. The formula for the five second withstand rating of a bare copper conductor is? WB 54 / IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 209

    The bare five second withstand rating must be used in what case only? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    cm divided by 29.1

    Used only where the equipment grounding conductor does not come into contact with the insulated current carrying conductors!
  48. The basic rule for all enclosures that contain a service conductor is what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 85
    That they must be bonded together.
  49. The formula for the five second withstand rating of an insulated copper conductor is? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)

    These values are proportional to the values given where? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    cm divided 42.25

    Table 250.122 in the NEC
  50. What NEC table provides conductor applications and insulations? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    T310.16b
  51. To get low impedance of the grounding system in an ac system what must be done? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 194
    The circuit conductors and the equipment grounding conductor must generally be kept together at all times.
  52. Not grounding the metallic enclosure can lead to what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 195
    Large induced voltages in surrounding metallic structures.
  53. The difference between the grounded and ungrounded system is what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 196
    The ungrounded system only has an equipment and enclosure grounding system and no grounded conductor.
  54. Circuit breakers have a different trip curve depending on whether they are_____? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 198
    Single, double, or three-pole configurations.
  55. The method employed for clearing a short circuit is different depending on whether the circuit is grounded or not. T or F? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    False
  56. The term current limiting indicates that a fuse will start to melt and clear the circuit in how many electrical degrees? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 199
    Melt in 90 and clear in 180 (half cycle)
  57. Whether fault current is a short circuit or a ground fault, the over current devices behind the device will see all of the fault current? T or F? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 200
    False. The ocpd ahead of the fault will see all of the current.
  58. When clearing a ground fault, two things control the current? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 201
    The impedance of the circuit, and the available short circuit current of the system.
  59. Emergency systems over current protective devices are required to be what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 201 NEC 700.27
    • Required
    • Selectively coordinated with all supply side over current devices.
  60. The grounded service conductor will carry how much of the fault current in most cases. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 203
    90% or more.
  61. If conduit couplings are installed wrench tight, as required by code, the increase in impedance of the conduit with couplings is about ________ % more than a straight run without couplings. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 206
    50%
  62. Table 250.122 has a rule of thumb that the equipment grounding conductor should not be less than ________% of the capacity of the phase conductors or the amp rating of the over current device that supplies the circuit. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 208
    25%
  63. The I2T values of the conductors given in Table 250.122 are about how many times their nominal continuous rating based on how many amperes for every __________ cm cross section. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 212
    • 13 and 28
    • one
    • 42.25 (Bare 5 second withstand rating)
  64. When 3-phase systems are installed, the primary is usually what type of connection? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 216

    What does a delta connection mean about which conductors are installed? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    Delta connected: secondary may be delta or wye

    A nuetral conductor is not installed
  65. A separately derived system has ___________ electrical connection? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    No direct
  66. What must be provided to the service or source of supply from the primary side of a transformer? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) WB 58
    An equipment grounding conductor
  67. Conductors derived from the secondary of a transformer, generator or other separately derived systems are considered what and are often referred to as? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 221
    Unprotected or unfused (line side) conductors and are often referred to as tap conductors.
  68. The sizing of the system bonding jumper for a separately derived system is to be based on? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) WB 59
    Derived phase conductors supplied by the separately derived system.
  69. A separately derived system that is grounded must have a grounding electrode conductor(s) to provide reference to earth for the enclosures and grounded conductor? T or F? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 222
    T
  70. Metal water piping must be used as a grounding electrode for a separately derived system within _________feet of entering the building. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 224
    5
  71. In a separately derived system, the grounding electrode shall be... IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)

    The grounding electrode shall be the nearest one of the following: NEC 250.30(a)7
    as near as practicable to and preferably in the same area as the grounding electrode conductor connection to the system.

    • Metal water pipe
    • Structural metal grounding electrode
  72. The grounding electrode conductor taps in a separately derived system must be connected to the common grounding electrode conductor where? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 225
    At an accessible location.
  73. Pertaining to Liquidtight flexible metal conduit used as an equipment grounding conductor, the maximum ampere ocpd protecting contained conductors for 1/2 and 3/8th and for 3/4 through 1-1/4 sizes is? The maximum ground return path cannot exceed what length? NEC 250.118 IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 158

    Liquidtight cannot be used as an equipment grounding conductor under what circumstance? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    • 20 amps - 1/2 and 3/8th
    • 60 amps - 3/4 through 1 1/4
    • 6 ft

    Where flexibility is necessary after installation.
  74. The maximum amperes allowed on an ocpd to protect the conductors contained in flexible metal conduit when it is used as an equipment grounding conductor is? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)

    Under what condition can flexible metal conduit not be used as an equipment grounding conductor? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 158
    20 amps

    where flexibility after installation is required.
  75. A person can become a path in an electrical circuit in one of two ways. What are they? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 250
    Series and parallel contact
  76. Series contact and Parallel contact are different in what ways? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 250
    • Series = the person is the only path to ground and no equipment grounding conductor involved
    • Parallel = equipment grounding conductor involved
  77. The GFCI continuously monitors the current balance between what two conductors? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 251
    Hot and neutral
  78. Several kitchen appliances, as well as portable heaters, are manufactured with 2-wire supply cords and, therefore, do/do not have their housings or enclosures grounded. Personnel can be protected by use of a ________. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 251
    • Do not
    • GFCI
  79. The most common two types of GFCI's are? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 252
    Circuit breaker and receptacle types
  80. GFCIs shall/ shall not be required for receptacles installed in those critical care areas where the toilet and basin are installed within the patient room. NEC 517.21
    Shall not
  81. The definition for bathroom uses what term that defines it not as a room? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 259
    Area.... not room.
  82. GFPE is required for what systems? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 267
    Solidly grounded wye electrical services of more than 150 volts to ground but not exceeding 600 volts phase to phase for each service disconnect rated 1000 amps or more.
  83. The maximum setting for GFPE shall be how many amperes? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 268
    1200
  84. GFPE: A system intended to provide protection of equipment from damaging line to ground fault currents by operating to cause a disconnecting means to _________________. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 269
    Open all ungrounded conductors
  85. There are two types of GFPE systems. What are they? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 269
    Zero-sequence (residual) and ground strap type
  86. The neutral ground strap type has a unique design feature in that what passes through the current sensor? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 269
    Main bonding jumper
  87. GFPE provides protection from burn downs at less than or greater than the ocpd rating? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 274
    Less than.
  88. The major advantage and disadvantage of a neutral ground strap type GFPE is(are) what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 269
    The advantage of a neutral ground strap type is that it is the least expensive, and the disadvantage is it is limited to application at the main service or supply source.
  89. The zero sequence (residual) and ground strap type of equipment ground fault protection system consists of a___________. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 269
    current sensor, control relay, and usually a shunt trip circuit breaker or shunt trip fused disconnect switch
  90. The most popular type of GFPE is? Also known as what and why? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 271
    • Zero sequencing type
    • the ground fault relay or system vectorally sums up the current through all four sensors and considers any excess current as residual.
  91. The ground fault relays that receive the input from the zero sequencing EGFP are field adjustable with what pickup ranges? Typical ranges for service are? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 272
    • 4 to 1200 amperes
    • 100 to 1200 amperes

    Note: shunt trip relays are usually connected through a shunt trip breaker or switch.
  92. GFP time delay settings are available in what range? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 272
    1.5 cycles to 60 cycles or one second
  93. The two most common types of selective coordination schemes are? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 273
    Cascading time delay scheme and the zone interlocking system.
  94. The hazardous locations in 501.30, 502.30, and 503.30 are primarily comprised of what respectively? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) Wb81
    Dust, gas, and ignitable fibers or filings.
  95. Hazardous locations generally require a(an) ________________in the raceway. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 282
    Equipment grounding conductor
  96. Hazardous locations generally require that locknuts on each side of the enclosure, or a locknut on the outside and a bushing on the inside can/ cannot be used for bonding. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 282
    Cannot
  97. Typical voltage ratings of conductors are? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 192
    300, 600, 2000, 5000, and 15000
  98. The main bonding jumper is permitted to consist of a(an)? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 81
    Wire, green screw, bus or other similar suitable conductor.
  99. What must carry the full ground-fault current of the system back to the grounded service conductor? its size must relate to what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 84
    • Main bonding jumper
    • the rating of the service conductors.
  100. What defines a ground ring. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) Wb 25
    A copper conductor not smaller than 2awg and at least 20 feet long that encircles the building or structure and is buried at least 30 inches deep
  101. A concrete encased electrode (ufor ground) is not less than?
    Not less than 2 inches in depth and 1/2 inch in diameter or 20 feet or more of bare copper conductors not smaller than 4awg. Wb 25
  102. Under what condition can an underground water pipe be used as a grounding electrode? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) WB 24
    A metal underground water pipe that is in direct contact with the earth for more than 10 feet shall be permitted to be used as a grounding electrode.
  103. Underground metal gas piping and aluminum can be used as grounding electrodes? True or False?
    False
  104. Where used outside, aluminum or copper clad aluminum grounding conductors shall not be terminated within ____ " of the earth. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) Wb 25
    18"
  105. Where plate electrodes are used, they shall have at least ______ square feet of surface in contact with exterior soil. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 26
    2
  106. Rod and pipe electrodes require how many feet in contact with the soil? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    8
  107. If a ground rod cannot be run vertically, or at a 45, then it can be run horizontally but must be how far under the soil? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    30"
  108. Where must supplemental grounding electrodes be used? (NEC 250.56) IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    Where a single rod, pipe, or plate electrode that is being used as a grounding electrode does not achieve a resistance to ground of 25 ohms or less, at least one additional electrode must be used.
  109. The grounding electrode conductor is permitted to be not larger than AWG CU/ AWG AL where it is the sole connection to a rod, pipe, or plate electrode. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) WB 30 (NEC 250.66a)
    • 6 CU
    • 4 AL
  110. Isolated powers systems are grounded/ ungrounded systems? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 298
    Ungrounded
  111. Isolated power systems usually consist of what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 299
    usually consists of a transformer that has an ungrounded secondary.
  112. The primary purpose of an isolated power system is to allow the equipment to do what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 299
    To function with the first line to ground fault without opening an OCPD.
  113. What must never be used on isolated power systems. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 299
    Wire pulling compound, since it has an adverse effect on the dielectric characteristics of the conductors and the system operation.
  114. Section 680.25(B) requires that, pertaining to pools, the equipment grounding conductor from a separately derived system be sized in accordance with what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 303
    • T250.66 based on the size of the derived phase conductors.
    • (note that this is the grounding electrode conductor sizing table, and not the equipment grounding conductor sizing table)
  115. Why is bonding required in a pool? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 304
    To reduce voltage gradients in the pool area.
  116. The mean of equalizing the potential of all equipment and parts so there will be no current between parts is referred to as? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 304
    Equipotential bonding.
  117. When an interconnection between the grounded (neutral) conductor and bonding grid exists this interconnection is often condidered what in regards to pools? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 304
    remote from the pool and is not intended to play a part in equipotential bonding.
  118. UPS systems are covered in section 645.15 of the NEC for IT rooms and specifically states that they shall not be considered what type of electrical system? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 325
    Separately derived
  119. The NEC does (does not) define what objectionable current is? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 325
    Does not
  120. Currents that introduce noise or data errors in electronic equipment shall (shall not be) considered the objectionable currents. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 325
    Shall not be
  121. The earth shall never be used for what purpose? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 326
    As an effective ground fault current path
  122. The electrical supply source is what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 326
    • utility transformer (or)
    • seperately derived system
  123. The equipment grounding conuctor and the isolated equipment grounding conductor use what two phrases in IT jargon? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 326
    Safety ground and clean ground
  124. Should an equipment grounding connection ever be made to a local grounding electrode when dealing with IT? why? A local grounding electrode is what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 326
    Never, becuase the grounding path resistance is too high.

    A local grounding electrode is building steel, water pipe, or driven electrodes.
  125. Does the NEC address whether isolated grounding is required, and this is addressed by whom? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 327
    No. The owner, design engineer, or manufacturer usually address this
  126. Isolated grounding means what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 327
  127. The enclosure supplied by the conductors in the raceway will be isolated by use of one or more nonmetallic raceway fittings.
  128. The term ground loops is (is not) defined in the NEC? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 329
    Is not
  129. What causes a ground loop? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 329
    Connecting computers and terminals on different circuits that are grounded to building steel (will allow) the shielded communications cable between the computer and terminal to complete the ground loop.
  130. what will cause noise current and can couple with data signals?

    Many computers data signals operate at how many volts? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 329
    Difference in ground potential

    5 volts or less
  131. A Balun coil is what? Is it effective at all frequencies?
    • A coil of insulated wire on a non-metallic core.
    • no
  132. What are some interface devices? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP329
    Surge arrestors and surge protective devices (SPDs)
  133. Known solutions to the problem of ground loops include? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 329
    • Single point grounding
    • Balun coil
    • Modems
    • Fiber optics
    • Optical insulators
    • Interface devices: such as surge arresters and surge protective devices (SPDs)
  134. Single point grounding is not suitable when? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 329
    At high frequencies and when in long distances using shielded cables
  135. The signal reference grid serves as a signal reference plane over a broad range of frequencies. They are correctly referred to as what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 331
    Broad band grounding systems
  136. The signal reference grid is an effort to reduce, eliminate or control the tendency of conductors connected to computers to resonate at lower frequencies. True or False? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 331
    False: they resonate at higher frequencies
  137. The effectiveness of the broad band grounding system or signal reference grid is improved how? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 332
    if it is solidly connected to the power supply for the it equipment by a very short strap
  138. Resonance occurs when? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 333
    the length of a conductor and the frequency of the alternating current are in tune.
  139. Good engineering practice requires that a conductor any longer than 1/20 of a wavelength cannot be counted upon to equalize voltages between its ends. This amounts to only 4.4 ft at 10 MHz. The significance of this is that unless conductors can be limited to less than ______ft in length, conventional grounding techniques with single point grounds might not be effective for signal and noise frequencies up to 10 MHz. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 333
    4-5 feet
  140. The use of what two methods appears to be the simplest and most reliable method for dealing with signals over 10MHz in frequency? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 333
    • Multi-point grounding
    • Short conductors
  141. Single-point grounding is typically applied to analog circuits with signal frequencies up to what? While digital circuits with signal frequencies in the what range should utilize multipoint grounding? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 334
    • 300 KHz
    • MHz
  142. Surge arrestors are permitted to be only installed at the service. True or False? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 334
    False: they may be at the service or on the load side of the service
  143. Two types of surge arresters become conductive when what is exceeded? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 334
    Threshold voltage
  144. Grounding systems create a path for what?
    Ground faults
  145. Surge protective devices come in 4 types. What are they? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 336
    • Type 1: secondary of service transformer to line side of service disconnect
    • Type 2: Load side of service disconnect (at branch panel)
    • Type 3: point of utilization
    • Type 4: Component SPD's
  146. Define a non-linear load. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 336
    A load where the wave shape of the steady-state current does not follow the wave shape of the applied voltage.
  147. A nonlinear load can cause several problems in the electrical supply system. Name 2. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    • Overloading neutral conductors
    • Creating excessive heat in transformers.
  148. Harmonic currents appear as reflected waves are multiples of the fundamental root frequency sine wave (60hz). The 3rd, 5th, and 7th are what freq? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 336
    • 3rd = 180hz
    • 5th = 300hz
    • 7th = 420hz
  149. Engineers will often specify what type of transformer in IT installations. They are designed for what? Rating is what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 336
    K transformers designed to handle the excessive heat from harmonics in the windings. K4-K20
  150. The term grounding conductor is referring to what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 337
    The conductor that is connected to an electrode that functions similar to a grounding electrode conductor.
  151. Most medium voltage systems in the ______ to ________kv range are either low resistance grounded or high resistance grounded. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 361
    2.4-15kv
  152. It is common in industrial systems to ground the neutral of systems rated ________volts and above through a resistor. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 361
    2400
  153. Reactance grounding (use of a reactor or grounding transformer) in the 2400 volts range is preferred if the circuits are overhead. Why? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 361
    Due to lightning
  154. Systems rated 15000 volts or more are usually ________ grounded, which permits the use of grounded neutral type ___________ that cost less and provide better protection from over voltages. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 361-362
    • Solidly
    • Surge arrestors
  155. Copper bus is rated on __________amperes per square inch. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 362
    1200
  156. A system neutral point is used for grounding high voltage ungrounded systems. The grounding type transformers include which kind? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 363
    Zigzag, wye-delta, T-connected (also known as Scott T)
  157. Solidly grounded neutral systems have two types of grounding. What are they? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 363

    What must be done with systems under 1kv? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    Single point and multi-point

    Multipoint and must be a grounding electrode every 1300 feet.
  158. The neutral conductor of a solidly grounded systems is generally permitted to have an insulation level of not less than ________volts or to be bare. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 363
    600 volts
  159. Single point grounded neutral systems are permitted for systems ________volts and greater. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 363
    1000
  160. Impedance grounded neutral systems can be accomplished by what 3 methods? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 364
    • Reactance grounding
    • Low resistance grounding
    • High resistance grounding
  161. Lightning protection systems consist of what 4 parts? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 372
    • Strike termination network
    • Down conductor network
    • Grounding electrode network
    • Equipotential bonding network
  162. Strike termination devices include what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 375
    • Air terminals
    • Metal masts
    • Building steel at least 3/16 inch thick
  163. The lightning zone of protection is determined by two methods. What are they? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 375
    • Protective angle
    • Rolling sphere (most popular)
  164. Air terminals are required to be located within _______of the ridge ends on pitched roofs or at edges and outside corners of flat or gently sloping roofs. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 376
    2 feet
  165. The zone of protection for an air terminal device is how many feet if not near flammable gases, etc.? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 375
    150
  166. Each strike termination device must be provided with a minimum of ________ path(s) to ground and additional down conductors are required on structures exceeding ________ ft in perimeter. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 379
    • 2
    • 250
  167. Down conductors are usually near corners of buildings. Why? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 379
    Corners provide a higher probability of streamer development and therefore lightning strike attachment.
  168. Approved lightning protection ground rods shall extend vertically not less than ________feet into the earth. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 381
    10
  169. Where corrosion is an issue, the bond between the incoming piping system and the lightning protection grounding system may be made through a _________. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 383
    Spark gap
  170. Magnetic and capacitive coupling from a lightning strike occurring up to __________ feet can induce a transient capable of damaging electrical and electronic systems. IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 384
    1500 feet
  171. An underground gas line can be used as a grounding electrode? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 386
    No
  172. Under art 250 there are two types of current paths. What are they? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    Effective ground fault current path and ground fault current path
  173. Where do you connect the neutral conductors on a PDU? What is this point called? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 325
    On the line side nuetral point of the service only, before the disconnect.
  174. Where are the connections to the signal reference grid in an IT room made? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 332
    Various IT units are connected by a flat copper braid and to the power supply for the IT units by a very short strap.
  175. Where does a system of less than 50 volts ac require grounding? NEC 250.20A IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1)
    • Where transformer supply exceeds 150 volts to ground
    • Where the transformer supply is ungrounded
    • Where installed outside as overhead conductors
  176. Equipment grounding conductors provide what? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 155
    An effective ground fault current path to facilitate OCPD operation in ground fault conditions.
  177. The term primary and secondary systems refers to what voltage respectively? IAEI, Soares Book on Grounding and Bonding, (notecard set g&b1) PP 36
    • Primary systems = 600 volts or more
    • Secondary systems = 600 volts or less

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