ERICO Practical Guide to Electrical Grounding - Manual (Page 20)

electrode conductor is connected to buried electrodes the
clamp or fitting must be listed for direct soil burial.
CADWELD offers the best solution for contractors trying
to meet the NEC requirements for connecting to rebar.
CADWELD offers a full line of connections in various
configurations for welding of grounding conductors to
reinforcing bars (Figure 1-31). Contractors should select
the point of attachment for such connections by locating the
weld away from areas of maximum tensile stress, such as
near the free end of the bar in a lap splice, to avoid harmful
stresses in the rebar. Note, where rebar mat is required to be
bonded, bar to bar bonds should be made with a copper
conductor jumper (Fig. 1-32). CADWELD connections
cannot be used to make direct rebar to rebar electrical
connections.
If a foundation with rebar is used as part of the grounding
electrode system, it is recommended that the anchor bolts
be bonded to the main rebars and a conductor extended
from the rebar to an outside electrode to minimize possible
damage to the foundation. See (Figure 1-33) and the
discussion on “Ufer” grounding on page 17.
The last component of the grounding electrode system is a
ground ring. The NEC requires that if a ground ring is
available it shall be bonded to the grounding electrode
system. A ground ring should consist of at least 20 feet (6.4
m) of No. 2 AWG bare copper or larger which encircles the
building. The ground ring should be in direct contact with
the earth at a depth below the earth surface of at least 2 1/2
feet (0.75 m). Contractors should note that while the ground
ring is frequently not “available,” it is becoming more and
more prevalent as a supplemental grounding system
component, especially when highly sensitive electronic
equipment is installed within the building. As noted above,
the connection to the ground ring will more than likely be a
direct burial connection so the ground clamps or fittings
must be listed for direct soil burial. ERICO has a full line of
cable-to-cable connections that can meet any installation or
application requirement (Fig. 1-34).
12 Practical Guide to Electrical Grounding
Fig. 1-33
RC
RR
RD
RJ
See Detail "A"
Detail "A Type RR
Cadweld Connection
Fig. 1-31
Fig. 1-34
PC XB
PT
SS
PH
TA
PG
PG
PG
XA
Fig. 1-32
Grounding Book 4/14/99 10/5/99 6:01 PM Page 12 (Black plate)