BLTPS-18
Sales Engineering
Technical Paper Series
T-Nut Grounding System
Grounded
Conductors. The
grounded
conductor shall not
be less than the
minimum size as
required by
250.241
Grounding
Conductor,
Equipment. The
conductor used to
connect the nocurrent-carrying
metal parts of equipment, raceways, and other
enclosures to the system grounded conductor, the
grounding electrode conductor, or both, at the
service equipment or at the source of a separately
derived system.2
Bonding of Electrical Equipment. Noncurrent-carrying conductive materials enclosing
electrical conductors or equipment, or forming
part of such equipment, shall be connected
together and to the supply system grounded
equipment in a manner that creates a permanent,
low impedance path for ground-fault current that
is capable of carrying the maximum fault current
likely to be imposed on it.3
General. The connection shall be made at any
accessible point from the load end of the service
drop or service lateral to and including the
terminal or bus to which the grounded service
1
230.42 (C)- Minimum Size and Rating, National Electric
Code 2002 Edition.
2
Article 100- definitions, National Electric Code 2002
Edition.
3
Article 250.4 (B) (2)- Bonding of Electrical Equipment,
National Electric Code 2002 Edition.
conductor is connected at the service
disconnecting means.4
The T-Nut Grounding
System is a new to
world design
incorporating the
grounding conductor
connection into the
cap of the grounded
conductor lug. The
low tolerance dovetail
cap provides adequate
bonding means of the
grounding and
grounded connections.
It meets all applicable
requirements of the
National Electric
Code, ANSI, and UL.
Testing proves that the T-Nut Grounding System
is comparable to other forms of attaching the
grounding conductor to the meter socket. The
test was performed per the UL dielectric testing
procedures. The test allows no more than 5ma
@ 2210 volts AC to pass from the device to any
current carrying surfaces. The test was
conducted on both the T-Nut Grounding System
and the industry standard, side mounted
grounding system. The table below shows the
results of this test. We found that the results
between the two systems were identical. In
addition, note the added clearance of the
conductor to either phase using the T-Nut
Grounding System. The T-Nut Grounding
System provides that much more protection
against possible short circuits. The simple
design also allows the cap to be added to existing
4
Article 250.24 (A) (1)- Grounding Service-Supplied
Alternating Current Systems, National Electric Code 2002
Edition.
Cooper B-Line, Inc. ٠ 509 West Monroe Street ٠ Highland, IL 62249 USA ٠ Phone: 618-654-2184 ٠ Fax: 618-654-1917 ٠ Email: blineus@cooperbline.com
© 2003 Cooper B-Line, Inc.
BLTPS-18
systems when additional grounding means are
needed.
Test Results:
Dielectric to Line A
Dielectric to Line B
Dielectric to Load A
Dielectric to Load B
Min. Distance from ground wire to
nearest energized component
Ma @ 2210 VAC
Side
T-Nut
Mount
.019ma .019ma
.020ma .020ma
.020ma .020ma
.019ma .019ma
1 5/8”
7/8”
Pictures of Test set-up:
Cooper B-Line, Inc. ٠ 509 West Monroe Street ٠ Highland, IL 62249 USA ٠ Phone: 618-654-2184 ٠ Fax: 618-654-1917 ٠ Email: blineus@cooperbline.com
© 2003 Cooper B-Line, Inc.