lightning protection ground loop location

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Natfuelbilll

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Can a lightning protection ground loop be installed inside the perimeter walls instead of installed external of the perimeter walls.
 
A ground ring shall be permitted if at least 18 inches under the earth and equal in size to the
main-size conductor.

This seems to be the only requirement for ground rings (or if you are a pilot, ground loops) and I would say is, like other grounding systems, not relevant to wall location.
 
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From Motorola's R56 Standard...

• Ground rings shall be installed in direct contact with the earth at a depth of 762 mm (30 in.) below the earth's surface whenever possible, or below the frost line, whichever is deeper (ANSI T1.334-2002, section 5.3.1 and NFPA 70-2005, Article 250.53).

• Building ground rings shall be installed at least 914 mm (3 ft.) from the building foundation and should be installed beyond the drip line of the roof. It is recommended that the building ground ring and ground rods be positioned 610 mm to 1.8 m (2 ft. to 6 ft.) outside the drip line of the building or structure to ensure that precipitation wets the earth around the ground ring and rods (MIL-HDBK419A and MIL-STD-188-124B).

• Tower ground rings shall be installed at least 610 mm (2 ft.) from the tower foundation (ANSIT1.334-2002, section 5.3.1).

IMO, in most cases a ground ring inside a building would not be in contact with moist soil. A site evaluation is needed to determine the best grounding for that site given the site conditions.

You could consider a Chemical Ground Rod/Well...

http://sitepro1.com/resources/pdf/assembly-drawings/38-605x.pdf
 
shortcircuit2 said:
From Motorola's R56 Standard...

• Ground rings shall be installed in direct contact with the earth at a depth of 762 mm (30 in.) below the earth's surface whenever possible, or below the frost line, whichever is deeper (ANSI T1.334-2002, section 5.3.1 and NFPA 70-2005, Article 250.53).

• Building ground rings shall be installed at least 914 mm (3 ft.) from the building foundation and should be installed beyond the drip line of the roof. It is recommended that the building ground ring and ground rods be positioned 610 mm to 1.8 m (2 ft. to 6 ft.) outside the drip line of the building or structure to ensure that precipitation wets the earth around the ground ring and rods (MIL-HDBK419A and MIL-STD-188-124B).

• Tower ground rings shall be installed at least 610 mm (2 ft.) from the tower foundation (ANSIT1.334-2002, section 5.3.1).

IMO, in most cases a ground ring inside a building would not be in contact with moist soil. A site evaluation is needed to determine the best grounding for that site given the site conditions.

You could consider a Chemical Ground Rod/Well...

http://sitepro1.com/resources/pdf/assembly-drawings/38-605x.pdf
Click to expand...

They have them on the inside around the perimeter too.
IPGB
Interior Perimeter Grounding Buss.
 
qcroanoke said:
They have them on the inside around the perimeter too.
IPGB
Interior Perimeter Grounding Buss.
Click to expand...


The OP is asking about the ground ring electrode.

The IPGB...Internal Perimeter Ground Bus is used inside on interior of the shelter, building, or room which contains many pieces electronic equipment that needs grounding (as part of the lightning protection system). The IPGB is typically mounted at 8 feet AFF running horizontally around the room supported at 2 foot intervals on 2-inch insulated standoffs...
 
Natfuelbilll said:
Does NFPA 780 require exterior placement?
Click to expand...

NFPA 780 is a standard...not a enforceable electrical code....as far as I know. Local building code may require compliance with the NFPA standard, or parts of it for certain facilities.

Insurance companies will/may also use the standard as a guide or requirement to insure a property.

Just laying a ground ring in the basement or under the slab of a building for lightning protection is not good practice or the intention of the ground ring. The ground ring needs to be in moist soil with a low resistance path to earth. Ground rings need to be "encircle" a building or structure. See 250.52(A)(4) for permitted ground ring electrodes for required NEC 250.50 GES's.
 
shortcircuit2 said:
The OP is asking about the ground ring electrode.

The IPGB...Internal Perimeter Ground Bus is used inside on interior of the shelter, building, or room which contains many pieces electronic equipment that needs grounding (as part of the lightning protection system). The IPGB is typically mounted at 8 feet AFF running horizontally around the room supported at 2 foot intervals on 2-inch insulated standoffs...
Click to expand...

He asked about lightning protection ground loop.
And you're not the only one who has a copy of R56
 
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