Lucent Technologies 555-670-116 User Manual
MERLIN LEGEND Communications System Release 7.0
Pocket Reference
Pocket Reference
555-670-116
Issue 1
April 1999
36
Power and Grounding
—
A metallic underground water pipe must be supplemented by
the metal frame of the building, a concrete-encased ground,
or a ground ring.
the metal frame of the building, a concrete-encased ground,
or a ground ring.
—
Other local metal underground systems or local underground
structures such as tanks and piping systems.
structures such as tanks and piping systems.
—
Rod and pipe electrodes, a 5/8-inch (1.6-cm) solid rod or
3/4-inch (1.9-cm) conduit or pipe electrode driven to a
minimum depth of 8 feet (244 cm).
3/4-inch (1.9-cm) conduit or pipe electrode driven to a
minimum depth of 8 feet (244 cm).
—
Plate electrode, a minimum of 2 square feet (61 square cm)
of metallic surface exposed to the exterior soil.
of metallic surface exposed to the exterior soil.
—
Concrete-encased ground, which must be an electrode,
consisting of one of the following:
consisting of one of the following:
—
At least 20 feet (6.1 m) of one or more steel reinforcing
rods, each being at least 1/2-inch (1.27 cm) in diameter.
rods, each being at least 1/2-inch (1.27 cm) in diameter.
—
20 feet (6.1 m) of bare copper conductor not smaller than
#4 AWG, encased in 2 inches (5 cm) of concrete. This
electrode must be located within and near the bottom of a
concrete foundation or roofing that is in direct contact with
the earth.
#4 AWG, encased in 2 inches (5 cm) of concrete. This
electrode must be located within and near the bottom of a
concrete foundation or roofing that is in direct contact with
the earth.
—
Ground ring, consisting of at least 20 feet (6.1 m) of bare
copper conductor not smaller than #2 AWG, encircling the
building. The ground ring must be in direct contact with the
earth and buried at least 2.5 feet (77 cm) below the earth’s
surface.
copper conductor not smaller than #2 AWG, encircling the
building. The ground ring must be in direct contact with the
earth and buried at least 2.5 feet (77 cm) below the earth’s
surface.
WARNING:
!
Do not use a metal underground gas piping system. This is a
safety risk.
safety risk.
For most power surges, the following standard grounding
requirements provide adequate lightning and surge protection:
requirements provide adequate lightning and surge protection:
—
Properly wired/grounded/bonded outside line protectors
—
Properly wired/grounded AC outlet
—
Properly grounded single-point ground bar
—
Properly wired connection between single-point ground and
power supplies
power supplies
Additional Power Surge Protection
The 391C1, 391A3, 391A2, and 391A1 power supplies have built-in
AC line protection. This built-in protection handles almost all
situations.
AC line protection. This built-in protection handles almost all
situations.
Occasionally, additional protection may be needed if the customer is
located in a heavy lightning area. The following products are
available:
located in a heavy lightning area. The following products are
available:
—
The 147A protector provides AC surge protection for
In-Range Out-of-Building (IROB) extensions. This protector
can also provide surge protection for the 391A power supply
module in heavy lightning areas.
In-Range Out-of-Building (IROB) extensions. This protector
can also provide surge protection for the 391A power supply
module in heavy lightning areas.