ERICO Practical Guide to Electrical Grounding - Manual (Page 115)

107 Chapter 6: Special Grounding Situations
Prefabricated wire mesh is custom made to meet the needs
of the installation. Wire size can range from No.6 AWG to
No.12 AWG (0.162 inch to 0.081 inch diameter). Widths up
to 20 feet (6.0 m) are available. The length will depend on
the roll weight which has a limit of 500 pounds (227 kg).
Prefabricated mesh is easily installed with no digging or
trenching. It is simply unrolled like a roll of carpeting. (Fig.
6-39) Adjacent rolls are easily and economically joined
using CADWELD type PG connections. (Fig. 6-40) On
large jobs, at least 30 connections per hour can be made.
Communications and shielding applications require
connections to the grounding electrode system. When used
as shielding inside a building, it is attached to the floor,
walls and/or ceiling, depending upon the installation. It can
be stapled to the wall studs or ceiling joists before the
finished surface is installed. (Fig. 6-41)
Mesh can also be installed in the concrete slab to be used as
a signal reference grid (SRG). Embedded ground plates
connected to the mesh and flush with the floor are used to
connect to the equipment. While thin flat strip SRGs are
usually used and laid on top of the finished concrete,
embedded mesh installations are also popular. (Fig. 6-42)
Prefabricated wire mesh, when installed in large areas
requiring interconnections between rolls, is furnished with
the cross wires overhanging the outside long wire equal to
an amount of 1/2 the mesh size plus 2 inches. (Fig. 6-43 and
6-44) As shown, this allows the mesh to be spliced side-to-
side or end-to-end while still maintaining the mesh opening
at the splice area.
When prefabricated wire mesh is used for personnel
protection from faults at switch handles, it is usually made
in 4 by 4 feet or 4 by 6 feet rectangular sheets although
larger sizes can be made. Some users also purchase the
mesh in rolls and cut off pieces as needed. The wire size
Fig. 6-39
Fig. 6-41
Fig. 6-42
Fig. 6-40
Fig. 6-43
To Equipment
Ground
ERICO
Ground
Bar
ERICO
Mesh
CADWELD
CADWELD
CADWELD
Lugs
CADWELD
Ground
Plate
Assembly
For applications of mesh used as signal reference grid (SRG) embedded in the concrete
floor, a CADWELD Cast Ground Plate is mounted flush with the finished floor and
connected to the mesh. Future equipment is then connected to the ground plate.
40'
5 Mesh Sections @ 12' = 60'
Splice
See Fig.
6-44
Grounding Book 4/14/99 10/5/99 6:02 PM Page 107 (Black plate)