The cables two shielding systems strand shield and

The cable’s two shielding systems
(strand shield and insulation shield
system) must be rebuilt when
constructing a splice. The same two
methods are used as outlined in the
reinsulation process: tape and molded
rubber.
For a tape splice, the cable strand
shielding is replaced by a semicon-
ductive tape. This tape is wrapped
over the connector area to smooth the
crimp indents and connector edges.
The insulation shielding system is
replaced by a combination of tapes.
Semi-con is replaced with the same
semi-conducting tape used to replace
the strand shield.
The cable’s metallic shield is
generally replaced with a flexible
woven mesh of tin plated copper
braid. This braid is for electrostatic
shielding only, and not designed to
carry shield currents. For conducting
shield currents, a jumper braid is
installed to connect the cables metallic
shields. This jumper must have an
ampacity rating equal to that of the
cables’ shields.
For a Cold Shrink
TM
or rubber molded
splice, conductive rubber is used to
replace the cable’s strand shielding
and the semi-conductive portion of the
insulation shield system. Again, the
metallic shield portion must be
jumpered with a metallic component
of equal ampacity.
A desirable design parameter of a
molded rubber splice is that it be
installable without special installation
tools. To accomplish this, very short
electrical interfaces are required.
These interfaces are attained through
proper design shapes of the
conductive rubber electrodes.
SPLICING
33
36
37
38
39
35
34

10
Laboratory field plotting techniques
show that the optimum design can be
obtained using a combination of
logarithmic and radial shapes.
5. Rejacket.
Rejacketing is accomplished in a tape
splice by using a combination of the
rubber splicing tape overwrapped with
a vinyl tape.
In molded rubber splice, rejacketing is
accomplished by proper design of the
outer semi-conductive rubber, effectively
resulting in a semi-conductive jacket.
When a molded rubber splice is used
on internally shielded cable (such as tape
shield, drain wire shield or UniShield®
cables), a shield adapter is used to seal the
opening that results between the splice
and cable jacket.
As a general summary, for the
versatility to handle practically any
splicing emergency, or for those situations
where only a few splices need to be made,
or when little detail is known about the
cable, the most effective splice is made
with tape or a tape kit.
For those times when cable size,
insulation diameter and shielding type
are known and when numerous splices
will be made, use molded rubber
splices for dependability and simplicity
as well as quick application.
(Reference: IEEE Std 48-1975. Quoted
with permission as follows:)
“This standard supersedes IEEE Std
48-1962 Standard for Potheads. (Note:
Current standard is IEEE Std. 48-1990)
“The superseded document
encompassed only the pothead, a
cable termination designed primarily
for cables having laminated insula-
tion, and which sealed the end of a
cable and provided insulation egress
for the conductor or conductors.