UFC 3-570-06
JANUARY 31 2003
conventional groundbed current. The material resembles electrical cable but actually
consists of a stranded copper conductor with an extruded, conductive polyethylene
jacket. This concept is used in underground concentric power cables as a conductive
shield around the ground wires. The polymer contains carbon granules that discharge
the current, leaving behind a polymer matrix. The anode should be backfilled in
carbonaceous coke breeze for maximum life. Some manufacturers offer an optional
plastic mesh, to separate the anode from the cathode in restricted spaces, preventing
electrical shorting between the anode and cathode. Currently, the material is available
in four different diameters and the current output ranges from 9.8 to 29.5 milliamperes
per linear meter (3 to 9 milliamperes per linear foot).
Table 2-14. Applicable Tables In MIL-HDBK-1004/10
Table
TITLE
1
Current Requirements for Cathodic Protection of Bare Steel
2
Current Requirements for Cathodic Protection of Coated Steel
5
Adjusting Factor for Multiple Anodes (F)
6
Correction Factor - Short Line Coating Conductance
7
Results of Structure-to-Electrolyte Potential Measurements
8
Standard HSCBCI Anodes
9
Special HSCBCI Anodes
10
Standard Wire Characteristics
11
M Factors for Determining Economic Wire Size (Cost of Losses in 100 Feet of
Copper Cable at 1 Cent per kWh)
2-7.3
Types of Impressed Current Anode Beds. The types of impressed current
anode beds are dependent on the placement, orientation, and depth of the anodes.
Impressed current anode beds are normally placed in remote earth, and distribute
current over long distances of the protected structure (pipelines, tank farms, distribution
systems etc.). Distributed impressed current groundbeds are sometimes used for small
2-52
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