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 INSTRUCTION
FOR TERMINATING & SPLICING
The
Kerite Company has developed a complete line of taped splices and
terminations for all voltage classes of Kerite cables. These splice
and termination designs are the result of years of field experience
and overvoltage testing at our Proving Grounds.
Although in
most cases experienced personnel are employed in making up splices
and terminations, certain guidelines and instructions are in order.
These are included on the back of each splice and termination print.
The applicable prints for various cable designs are available from
a Kerite representative.
Commercially
available pre-molded, cold or heat-shrink splices and terminations
may be used on Kerite cables. Our evaluation of many devices show,
when they are installed per the manufacturer’s instructions, they
do not affect the cable’s performance. However, the Kerite Company
has no control over the design, manufacture or use of these splices
and terminations, therefore, we cannot assume any liability for
their performance.
Methods
for Stripping of FR, PVC and PE Jackets
and Lead Sheaths
1.
All jackets and lead sheaths should be stripped using the
"tear-strip" technique. This consists of making two
parallel scoring cuts between
1/4 " and 1" apart followed by ripping out the strip of jacket between, and then removing
the remainder. The depth of the cut necessary
is approximately half-way through the
jacket or layer.
2.
The preferred method of making the scoring cuts with any
kind of knife is to hold the knife straight
in toward the cable, contrary to the method used in stripping braids
and tapes.
3.
Similar scoring and ripping may also be used circumferentially at the terminus of the stripped portion.
4.
The circumferential cutting of thin plastic layers either
over tapes or the Kerite insulation can be neatly accomplished
by using a narrow strip of abrasive cloth or
any heavy string or twine as a wrap-around
abrading tool. The heat generated by
a see-saw motion of the string will cut a neat furrow in the plastic without loosening its
ends or risk of cutting the underlying
material.
5.
For the stripping of braid, it is recommended that a light
score be made on the braid followed by subsequent light
strokes with the knife held flat to the cable
surface.
SPLICE
AND TERMINATION PRINTS REFERENCE
Splice
and termination prints can be ordered from Kerite by requesting
the appropriate prints and instruction. The numbering system is
as follows:
| Type
|
Voltage |
Cable
Design |
Shield
|
| Splice
= S
Indoor
Termination
= IT
Outdoor
Termination
= OT |
5kV
= 5
8kV = 8
15kV = 15
25kV = 25
35kV = 35
46kV = 46
69kV = 69
115kV = 138
138kV = 138 |
Single
Permashield = SP
Double or
Triple
Permashield = P |
Non-Shielded
= NS
Metal
Tape = MT
Concentric
Wires = CW
Wire
Braid = WB
Lead Sheath
= LS |
Example: A splice print for a 15kV single
Permashield tape shielded cable is as follows: S-15-SPMT
A splice print for a 35kV single Permashield tape shielded with concentrics
cable is as follows: S-35-SPMT-CW
METHODS FOR STRIPPING
METAL TAPE
Scissors
Technique
The
scissors-cut technique is the preferred method of stripping metal tape at the overlapped end (the tape
will unwrap from the end of the cable).
Figure
1
Circumferentially
mark the intended end point of metal tape.
Unwrap from cable ends one to two turns beyond the mark. Hold the tape out from cable and cut along mark
with scissors. Round off sharp point.
Rewrap and hold in place with turn of
vinyl tape set 1/4" back from edge.
 |
FIGURE 1
SCISSORS TECHNIQUE
At the Overlapped Tape End |
Knife
Technique
Recommended
at underlapped metal tape end or if no scissors are available.
Figure
2
At
end with underlapped tape, apply friction tape binder
at the intended end point of metal tape as shown in sketch. Score through outer layer of metal tape along
edge of friction binder only in that
area where metal tape is lapped to prevent
cutting into underlying insulation. Lift corner tab and tear around circumference guided by friction binder,
remove binder and tamp down the tape edge to
lay flat. To prevent metal tape from
accidentally loosening over a long length
of cable having no outer covering, apply a friction tape binder 3" beyond end point of metal
tape before staring stripping procedures.
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FIGURE
2
KNIFE TECHNIQUE
At the End with Underlapped Tape |
Figure
3
At
end with overlapped tape, apply binder so edge of friction
tape is at the intended end point of metal tape as shown in Figure 3. Cut at lap as above. Lift tab and
tear metal tape around the circumference
along edge of binder. Fold or cut off
sharp point of tape and rewrap onto cable. Hold in place with a turn of vinyl tape set 1/4" back from end. Remove friction binder and unwanted metal tape, then tamp torn
edge to lay flat.
 |
FIGURE
3
KNIFE TECHNIQUE
At the End with Overlapped Tape
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Connectors
It
is recommended that compression connectors be used
whenever possible in Kerite splices. They are simple to install, reliable, and reproducible (not subject
to wide variation in technique.)
Although
solder joints have not shown evidence of electrical
problems on any Kerite cables to date, it is conceivable that poor technique could overheat the cable
at the joints. Consequently, because
of the wide variation in soldering techniques possible in the field, we have
recommended the use of compression type
connectors.
In
those situations where solder connections are used, the
following procedure is recommended to assure a higher degree of confidence in the joints.
1.
The insulation should not be tapered prior to the soldering
operation.
2.
A layer of cotton tape should be applied over the insulation
binding it down firmly to the conductor approximately
5" back from the splice on either side of the
connector. This will improve the heat
transfer from the conductor to the insulation, and shorten the cooling time.
3.
Heat resistant tape or cord should be applied between the
connector edge and the insulation edge to prevent the molten solder from directly contacting the insulation.
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