The resistance to ground shall be measured using the fall-of-potential
method described in IEEE Std 81. The maximum resistance of driven ground
shall not exceed 25 ohms under normally dry conditions. If this resistance
cannot be obtained with a single rod, [_____] additional rods not less than
1.8 m 6 feet on centers, or if sectional type rods are used, [_____]
additional sections may be coupled and driven with the first rod. In
high-ground-resistance, UL listed chemically charged ground rods may be
used. If the resultant resistance exceeds 25 ohms measured not less than
48 hours after rainfall, the Contracting Officer shall be notified
immediately. Connections below grade shall be fusion welded. Connections
above grade shall be fusion welded or shall use UL 467 approved connectors.
2.2.2.4
Cabinet Paint System
[The cabinet and mounting support shall be [painted] [hot dipped
galvanized] [aluminum] [stainless steel] with the manufacturer's standard
paint system.] [The mounting support for the fiberglass cabinet shall be
[painted] [hot dipped galvanized] [aluminum] [stainless steel] with the
manufacturer's standard painting system.]
2.2.3
Wiring
Wiring shall be installed in accordance with NFPA 70 utilizing type TW or
RHW or polyethylene insulation. Fittings for conduit and cable work shall
conform to UL 514A. Outlets shall be of the threaded hub type with
gasketed covers. Conduit shall be securely fastened at 2.4 m 8 foot
intervals or less. Splices shall be made in outlet fittings only.
Conductors shall be color coded for identification. Cable for anode header
and distribution shall be No. [2] [_____] AWG stranded copper wire with
type [cathodic protection high molecular weight polyethylene] [Dular/Halar]
insulation.
2.2.4
Oil Immersed Enclosures
**************************************************************************
NOTE: The enclosure should not be used in areas
prone to flooding unless required for hazardous
locations. Provisions should be made for flooding.
**************************************************************************
Enclosures shall be of 3.1 mm 11 gauge steel or heavier, with an accessible
drain plug. The oil level shall be clearly marked. The lid shall be
hinged and have quick release clamps to secure it in closed position. A
stop shall limit the swing of the lid when opened. A compressible, oil
resistant, positive sealing gasket shall be provided. The gasket shall
return to its original shape upon release of lid pressure. The gasket
shall be attached to the tank or lid and joints shall be free of gaps.
Base mounting using 102 mm 4 inch high channels shall be provided.
Conduits entering the enclosure shall be internally sealed and shall enter
or exit above the oil fill line.
2.3
MISCELLANEOUS MATERIALS
2.3.1
Reference Electrodes
The electrodes shall be copper-copper sulphate type provided with
micro-pore diffusion window for water contact and water-tight plug for
renewal of copper sulphate crystals and solution. A minimum of four
SECTION 13111A
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