MIL-HDBK-1004/10
Table 10
Standard Wire Characteristics
OVERALL
APPROX.
MAXIMUM
DIAMETER
WEIGHT
MAXIMUM
MAXIMUM DC
ALLOWABLE
SIZE
NOT
NOT
BREAKING
dc
AT 20 EC
CURRENT
AWG
INCLUDING
INCLUDING
STRENGTH
INSULATION
INSULATION
(lb)
(ohms/M ft)
CAPACITY
(in.)
(lb/M ft)
(A)
14
0.0726
12.68
130
2.5800
15
12
0.0915
20.16
207
1.6200
20
10
0.1160
32.06
329
1.0200
30
8
0.1460
50.97
525
0.6400
45
6
0.1840
81.05
832
0.4030
65
4
0.2320
128.90
1320
0.2540
85
3
0.2600
162.50
1670
0.2010
100
2
0.2920
204.90
2110
0.1590
115
1
0.3320
258.40
2660
0.1260
130
1/0
0.3730
325.80
3350
0.1000
150
2/0
0.4190
410.90
4230
0.0795
175
3/0
0.4700
518.10
5320
0.0631
200
4/0
0.5280
653.30
6453
0.0500
230
250 MCM
0.5750
771.90
7930
0.0423
255
Insulation. The connections between the cathodic protection power
6.7.1.2
source and the anodes are usually submerged or buried at least over part of
their length. These cables are extremely susceptible to failure as they are
operated at highly positive potentials. Any contact between the metallic
conductors and the environment will result in rapid deterioration of the
conductor and loss of continuity of the protective circuit. Anode lead wires
should never be used to suspend, carry, or install the anode except in water
storage tanks.
High molecular weight polyethylene (HMWPE) insulation has proven to
give satisfactory service for the insulation of this critical connection in
most shallow buried applications. Where exposure to chlorine is encountered,
such as in seawater or in deep anode applications, chlorine resistant
insulation such as fluorinated ethylene propylene (FEP), tetrafluorethylene
(TFE), and polyvinylidene fluoride (PVF2) are used either singly or in
combinations with thicknesses of up to 0.150 inches. These materials are also
used over a primary insulation of extruded polyalkene, 0.30 inches thick, or
are covered with a jacket of high molecular weight polyethylene for mechanical
protection.
A highly successful insulation for such highly critical
applications has been a system consisting of a 0.065-inch-thick high molecular
weight polyethylene outer jacket for abrasion resistance combined with a
0.040-inch-thick ethylene-monochlorotrifluroethylene copolymer (E-CTFE). For
less critical applications such as the negative lead to the rectifier, test
wires and aboveground wiring, thermoplastic insulation (type TW), synthetic
rubber (RHW-USE), or polyethylene may be used.
Recommended Cables for Specific Applications. Because of
6.7.1.3
similarities in required characteristics of the various connecting cables in
many impressed current cathodic protection systems, general specifications for
cable sizes and types for many cathodic protection system requirements have
been established and are given below:
92
Previous Page
