Copper-clad steel rods will be specified for normal
conditions. Zinc-coated steel or stainless steel
rods will be used where low soil resistivities are
encountered and galvanic corrosion may occur between
adjacent underground metallic masses and the
copper-clad rods. Stainless steel rods have a
longer life than the zinc-coated steel, but use of
zinc-coated steel must be justified based on the
higher cost. Rods 16 mm (5/8 inch) in diameter and
2.5 m (8 feet) in length are generally acceptable;
however, in rocky soils 19 mm (3/4 inch) rods shall
be specified. In high resistivity soils, 3 m (10
foot) or sectional rods may be used to obtain the
required resistance to ground. Where rock is
encountered, additional rods, a counterpoise, or
ground grid may be necessary. Coordinate and
standardize rod selection for individual facilities
with other specification sections.
**************************************************************************
Ground rods shall be of [copper-clad steel conforming to UL 467]
[zinc-coated steel conforming to ANSI C135.30] [solid stainless steel not
less than [16] [19] mm [5/8] [3/4] inch in diameter by [2.5] [3] m [8] [10]
feet in length] [of the sectional type].
2.4.5
Power Supply
**************************************************************************
NOTE: Locations with automatic backup power
generation shall require as a minimum 4 hours backup.
**************************************************************************
The operating power for the system shall be single phase taken from the
building electric service as specified in paragraph Power Supply for the
System. Emergency backup power shall be provided by sealed [lead-acid]
[or] [nickel-calcium] type batteries requiring no additional water. The
charging system shall recharge fully discharged batteries within 12 hours
and maintain the batteries in the fully charged state. The battery shall
have the capacity to operate the system for not less than 48 hours under
maximum normal load with the power supply to the charger disconnected.
2.4.6
Wiring
Wiring shall be in accordance with NFPA 70 and as indicated.
Station
wiring shall be color coded.
2.4.7
Special Tools and Spare Parts
Special tools necessary for the maintenance of the equipment shall be
furnished. One spare set of fuses of each type and size required and 5
spare lamps of each type shall be furnished.
PART 3
EXECUTION
3.1
INSTALLATION
All work shall be installed as shown and in accordance with the
manufacturer's recommendations, unless otherwise specified. Necessary
interconnections, services, and adjustments required for a complete and
SECTION 13852A
Page 18
Previous Page
