Lightning Protection

[jokoMalong]

Hello Guys,
I just want to ask if it's necessary to put/install a ground rod in every down conductor? I am using a Mesh method here Class 1 and I have a total of 22 down conductors. My system also have 4 Lightning Arresters (1 on every corner). Also, how many ground test well should I install? Thank you in advance for your inputs

 

[Julius Right]

Which standard you intend to follow:

NFPA 780 or IEC 62305?

 

[jokoMalong]

Which standard you intend to follow:

NFPA 780 or IEC 62305?

NFPA 780 Sir.

 

[Julius Right]

According to NFPA 780:

4.13.1.1 Each down conductor shall terminate at a grounding electrode dedicated to the lightning protection system.

[That means no.of grounding electrodes=no.of down conductors]

4.13.1.2 The design, size, depth, and number of grounding electrodes used shall comply with 4.13.2 through 4.13.8

4.13.4 Ground Ring Electrode. A ground ring electrode encircling a structure shall be as shown in Figure 4.13.4.

4.13.4.1 The ground ring electrode shall be in direct contact with earth at a depth of not less than 460 mm (18 in.) or encased in a concrete footing in accordance with 4.13.3.

4.14.1 General. All grounding media and buried metallic conductors that can assist in providing a path for lightning currents in or on a structure shall be interconnected to provide a common ground potential.

 

[jokoMalong]

According to NFPA 780:

4.13.1.1 Each down conductor shall terminate at a grounding electrode dedicated to the lightning protection system.

[That means no.of grounding electrodes=no.of down conductors]

4.13.1.2 The design, size, depth, and number of grounding electrodes used shall comply with 4.13.2 through 4.13.8

4.13.4 Ground Ring Electrode. A ground ring electrode encircling a structure shall be as shown in Figure 4.13.4.

4.13.4.1 The ground ring electrode shall be in direct contact with earth at a depth of not less than 460 mm (18 in.) or encased in a concrete footing in accordance with 4.13.3.

4.14.1 General. All grounding media and buried metallic conductors that can assist in providing a path for lightning currents in or on a structure shall be interconnected to provide a common ground potential.

Thank you Sir Julius , another question Sir, Is Ground Ring Electrode synonymous to Counterpoise?

 

[Julius Right]

I think you are talking about radials [see NFPA 780 4.13.5* Radials.] You may combine the grounding ring with some radials ,of course.

 

[jokoMalong]

Is radials same with loop conductor? Im thinking not sir, correct me if I'm wrong. Is there any part of NFPA 780 or 70 talking about installation of Loop Conductor?(how deep it should be installed)

 

[jokoMalong]

I think Ground ring electrode is the Loop conductor.

 

[Julius Right]