Custom Search
|
|
|
||
 TM 5-684/NAVFAC MO-200/AFJMAN 32-1082
(1) Scrape the lead in the vicinity of the dam-
toxic gas will dissipate fast. Follow instructions for
SF, gas handling in chapter 15, section II.
age.
(4) Cable insulation. If the cable insulation
(2) Preheat area using an acetylene or gas blow
fails, the repair should be made as given for solid
torch. Care should be taken not to melt lead.
dielectric insulated cables.
(3) Apply a good flux such as stearine.
f. Armor. There are various types of armor to pro-
(4) Apply solder and heat to a point where it is
vide mechanical protection for the cable insulation
pliable.
and some armor is provided with a protective
(5) Work sold er into sheath with a paddle or
jacket.
stick and smooth.
(1) Flat metal armor. When flat metal armor is
(6) Wipe with wiping pad.
broken, it can be repaired in place by soldering the
d. Concentric-neutral cable construction. The
broken part or by overlapping a short piece of armor
neutral conductor of this type of cable consists of
and soldering. The armor should be thoroughly
equally spaced strands of wire or flat strap wrapped
cleaned and tinned before soldering. If the armor
spirally around the outside of the cable insulation.
becomes loose at the ends of the cable, it may be
Concentric neutral cables may be of a single or
wired to the lead sheath or a lead sleeve installed at
multiple conductor configuration and may have an
each end.
outer protective jacket over the neutral conductors.
(2) Inter-Locked armor sheath. The interlocked
Care must be used in handling the cable to prevent
armor sheath may sometimes be separated during
the concentric-neutral conductors from loosening or
installation. Short sections of this armor can usu-
bunching together in one place around the cable
ally be worked into place (one section at a time) by
circumference. If this occurs, it may cause tracking
using a hammer and screwdriver or other blunt
of the insulation or affect the voltage stress distri-
instrument. The armor may sometimes become
bution within the insulation. The number and size
dented. When not too seriously dented, no repair
of the concentric conductors are determined by the
should be attempted. However, if the dent is serious
manufacturer in accordance with ICEA standards.
enough to cause possible injury to the cable, a sec-
Repairs should ensure that the operating character-
tion of armor should be removed and replaced with
istics of the concentric neutral are not adversely
a sleeve.
affected.
(3) Wire armor The wire armor over submarine
e. Gas-pressurized cable. Repairs may be re-
cable may sometimes become bent and separated.
quired for this cable because of a loss of pressure
In such cases, the armor should be replaced, bound
from a leak in the outer covering or conduit or a
with wire, and soldered. The binding wires should
puncture in the solid dielectric cable.
be of a metal similar to that of the armor. If the wire
(1) Gas pressure. The high density of the gas
armor is broken, it can be repaired in a similar
may result in a zero gage reading even though suf-
manner. After the link has cooled it should be
ficient gas is still present to keep out air and mois-
painted with a heavy coat of insulating compound to
ture. If the cable is under a water-pressure static-
reduce any possible dissimilar metal corrosion.
head, then a pressure of 0.5 pounds per square inch
(4). Protective jacket over armor. Sometimes a
gage (3.5 kilopascals gage) is needed for each foot
protective jacket such as rubber, thermoplastic, or
(0.3 meters) of water head to continue to keep water
braid is placed over the armor for protection against
out.
corrosion. Should these jackets become damaged,
(2) Repair of gas Leaks. Follow the manufactur-
the damaged area can be repaired by wrapping with
er's recommendations. A beep detector should be
thermoplastic tape or self-vulcanizing tape.
used to ensure all leaks have been repaired. Sur-
faces should be clean and smooth, and the pressure
5-25. Other cable component repairs.
must generally be dropped back to zero.
Potheads and terminations should be checked along
(3) Treatment of gas. The SF, gas used is non-
with any cable fireproofmg.
toxic and odorless. However any arcing produced by
the fault will result in the gas producing toxic ma-
terials that smell like sulfur and rotten eggs. Do not
clean, and bodies of the compound-filled termina-
breath this gas. Let it dissipate to the air and clear
tions, such as potheads, should be checked for leaks.
it from a structure. Since the gas will be outside the
A leak will usually be indicated by oozing out of the
shield with a solid dielectric cable, the cable can fail
compound. In such instances, the leak should be
without arcing the gas. If a cable were to fail and
repaired and the pothead refilled. A power factor
burn a hole through the insulation and then be
test (as covered in section VII) of the termination
re-energized, a very small amount of gas in the hole
and cable will give some indication of the condition
could arc and may be noticeable. The smell and
of the termination so far as electrical leakage and
5-13
|
 
|
|
|
||
