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5th Year, Week 6 (Lightning Protection, Torque) > Lightning Protection > Flashcards

Lightning Protection Flashcards

1
Q

What book published by the NFPA is the standard for installation of lightning protection systems?

A

NFPA 780

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2
Q

The tip of air terminals must rise at least __ inches above the surface they are protecting.

A

10”

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3
Q

Lightning cables must be strapped/supported at least every __ feet in exposed installations.

A

3’

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4
Q

All structures (with roof perimeter of 250’ or less) must have at least __ down conductors.

A

2

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5
Q

Except for concrete encased electrodes, a ground ring used as the electrode for a lightning protection system must be at least __ feet from the footing.

A

2’

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6
Q

What does LPS stand for?

A

Lightning Protection System.

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7
Q

Metal objects with potential to ground within __ must be bonded to the LPS.

A

6’

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8
Q

Air terminals must not be more than __ inches away from corners or edges.

A

24”

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9
Q

The minimum bend radius for cables is __ inches at __ degrees.

A

8 inches at 90 degrees

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10
Q

On average, down conductors should not be spaced more than ___ feet apart.

A

100

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11
Q

Before driving a ground rod for LPS, it is recommended you first dig a hole __ feet deep in which to drive.

A

2’ (2’ hole + 8’ rod = required 10’ depth)

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12
Q

At the foundation of a building, all metal objects with potential to ground within __ feet must be bonded.

A

12’

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13
Q

Air terminals that extend between 10-24” shall be spaced no less than __ feet apart.

A

20’

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14
Q

Structures with 250’ or less of roof perimeter are only required to have __ down conductors.

A

2

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15
Q

T/F: As many grounds are required as there are down conductors.

A

True

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16
Q

Of buildings 60’ tall or higher, All metal objects with potential to ground within __ feet of the LPS shall be bonded to it.

A

12’

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17
Q

Air terminals that extend 24” or higher shall be spaced no less than __ feet apart.

A

25’

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18
Q

Structures with over 250’ of roof perimeter shall require an additional down conductor for each additional ___ feet of roof perimeter.

A

100’

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19
Q

If a system had 2 ground rods, they would need to be spaced __ feet. Likewise, if a system had 3 ground rods, they would need to be spaced __ feet.

A 
2 = 20'
3 = 30'
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20
Q

T/F: If a conductor is ran through a metal conduit, it only needs to be bonded at one end.

A

False, both ends

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21
Q

In addition to strike terminals located around the perimeter of the roof, flat or gently sloping roofs that exceed 50’ in width or length must have additional strike terminals installed at intervals not exceeding __ feet.

A

50’

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22
Q

Exposed down conductors must be protected from physical damage within __ feet from the floor.

A

6 feet

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23
Q

A ground loop is required if a building is __ feet or more in height.

A

60’

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24
Q

Aluminum cables and fittings shall not be used within __ inches of grade.

A

18”

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25
Q

Ground loops must be installed a minimum of __ inches deep.

A

18”

26
Q

T/F: Steel structures are allowed to be used as down conductors.

A

True, as long as they meet certain requirements.

27
Q

Well casings within __ feet of the LPS must be bonded.

A

25’

28
Q

Where vertical steel structure (I-beams) are used as down conductors, they may not be used if spaced more than __ feet apart.

A

60’

29
Q

T/F: Electrical service grounds and lightning protection grounds are installed separately, but are connected.

A

True (usually at the intersystem bonding termination

30
Q

Steel structure must be at least __ thick to be used as a down conductor.

A

3/16”

31
Q

The minimum surface area for a bonding plate on structural steel is __ square inches.

A

8

32
Q

____ equipment is for structures, buildings or parts of buildings 75 feet or lower.

A

Class 1

33
Q

____ equipment is for structures, buildings, or parts of buildings that exceed 75 feet.

A

Class 2

34
Q

T/F: Everything in a LPS must be labeled for lightning protection.

A

True

35
Q

LP ground rod connectors have 2 screws and must have __ square inches of surface area.

A

1.5”

36
Q

Copper conductors must be __ percent conductive when annealed.

A

95 percent

37
Q

Class 1 COPPER materials:
___ lbs per 1000ft.
__ awg stranding
__” air terminals

A

187 lbs
17 awg
3/8” air terminals

38
Q

Class 2 COPPER materials:
___ lbs per 1000ft.
__ awg stranding
__” air terminals

A

375 lbs
15 awg
1/2” air terminals

39
Q

Class 1 ALUMINUM materials:
___ lbs per 1000ft.
__ awg stranding
__” air terminals

A

95 lbs
14 awg
1/2” air terminals

40
Q

Class 2 ALUMINUM materials:
___ lbs per 1000ft.
__ awg stranding
__” air terminals

A

195 lbs
13 awg
5/8” air terminals

41
Q

Terminals, bases, and fitting installed within __ inches of a chimney or vent must be electro-tin plated.

A

24”

42
Q

Concrete encased electrodes must be encased within __ inches of concrete and have at least __ feet of conductive material within the concrete.

A

2 inches, 20 feet

43
Q

Radial conductors must be at a __ degree angle from each other, __ feet out from the building, and __ inches deep.

A

90 degree, 12’, 18”

44
Q

T/F: The gas meter should be bonded on the utility side.

A

False. bond the customer side

45
Q

A(n) ___ is an electrical spark, caused by differences of potential between conductive metal bodies or between conductive metal bodies and a component of a lightning protection system ground.

A

Side Flash

46
Q

What are the 6 types of roofs?

A
  1. ) Flat
  2. ) Hip
  3. ) Mansard
  4. ) Gable
  5. ) Broken Gable
  6. ) Gambrel
47
Q

The ‘Zone of Protection’ is pictured as a sphere with a radius of ___ feet.

A

150’

48
Q

Concealed vertical runs must be bonded every ___ feet, and horizontal every ___ feet.

A

200’, 100’

49
Q

Wood buildings must be bonded every ___ feet, vertically.

A

60’

50
Q

A(n) ___ is a specific measured limiting voltage rating assigned to a surge protective device (SPD).

A

SVR (Suppressed Voltage Rating)

51
Q

A(n) ____ is a transient wave of current, potential, or power in an electric circuit. They do not include longer duration temporary overvoltages consisting of an increase in the power frequency voltage for several cycles.

A

Surge

52
Q

A(n) ____ is a protective device for limiting surge voltages by discharging or bypassing surge current; it also prevents continued flow of follow current while remaining capable of repeating these functions.

A

Surge Arrestor

53
Q

A(n) is a device composed of any combination of linear or nonlinear circuit elements intended for limiting surge voltages on equipment by diverting or limiting surge current.

A

SPD (Surge Protective Device)

54
Q

A(n) ____ is a subcycle disturbance in the AC waveform that is evidenced by a sharp, brief discontinuity of the waveform. It can be of either polarity and can be additive to or subtractive from the nominal waveform.

A

Transient

55
Q

A(n) ____is a protective device for limiting transient voltages by diverting or limiting surge current; it also prevents continued flow of follow current while remaining capable of repeating these functions. This term is being replaced by Surge Protective Device (SPD).

A

TVSS (Transient Voltage Surge Suppressor)

56
Q

The ____ is a rating (or ratings) selected by the manufacturer based on the measured limiting voltage determined when the SPD is subjected to a combination waveform with an open circuit voltage of 5 kV and a short circuit current of 3 kA. The value is rounded up to the next highest 100 V level.

A

VPR (Voltage Protection Rating)

57
Q

The ____ is the maximum designated root mean square (rms) value of the power frequency voltage that may be continuously applied to the mode of protection of an SPD.

A

MCOV (Maximum Continuous Operation Voltage)

58
Q

The ____ is the maximum instantaneous value of the current through the SPD having an 8/20-microsecond waveform.

A

Maximum Discharge Current (I-max)

59
Q

The ____ is the peak value of an 8/20-microsecond current waveform selected by the manufacturer for which an SPD remains functional after 15 surges.

A

Nominal Discharge Current (I-n)

60
Q

T/F: At grounded services, SPD’s should be wired in either Line-Ground or Line-Neutral configurations.

A

True

61
Q

An additional SPD is required if an electric system leaves the building to supply another building and the conductors are ran over ___ feet .

A

100’

5th Year, Week 6 (Lightning Protection, Torque) (2 decks)

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