Cut Sheet

1. Product Description
3M
™
Cold Shrink Silicone Rubber Termination Kits
QT-II 5620K Series contain one-piece, non-skirted, silicone
rubber terminations, qualified as IEEE Class I for weather-
protected applications. Termination assemblies consist of a
high dielectric constant (Hi-K) stress control tube insulated
with a non-tracking silicone rubber insulator, prestretched
and loaded together onto a removable core. The kits are
designed for terminating solid dielectric shielded power
cable rated 5 through 15 kV, with ribbon shield, wire shield
and UniShield
®
constructions.
Kit Contents:
Each kit contains sufficient quantities of the following
materials to make three single-phase terminations
(compression lugs are not included in the kit).
3 Hi-K non-tracking silicone rubber terminations
3 mechanical ground strap assemblies
Roll of Scotch
®
Electrical Semiconducting Tape 13
3 strips of Scotch Shielding Tape 24
3 strips of Scotch Silicone Rubber Electrical Tape 70
(except 5625K kit, which contains 1 roll)
3 packets of silicone grease
Sealant kit
Cable preparation kit
Instructions
Termination Features:
Conforms to IEEE Standard 48 requirements for Class I,
15 kV terminations.
One-piece versatile design, allowing quick installation
and accommodating a wide range of cable sizes.
Cold Shrink delivery system for easy installation. Simply
place termination over prepared cable and unwind core to
shrink into place (no force fit required).
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•
•
Hi-K stress control. Specially formulated high-impulse
material minimizes surface stress by uniformly distributing
the electrical field over the entire surface of the insulator.
Compact design provides for easier installation in
restricted spaces.
Silicone rubber insulators and EPDM stress control tubes
are compatible with all common solid dielectric insula-
tions, such as polyethylene, cross-linked polyethylene
(XLP), and ethylene propylene rubber (EPR).
Stress Control
The QT-II termination is designed to control the electric
field stress distribution with a special Hi-K material which is
an integral part of the termination. The Hi-K material, with
a dielectric constant (K) of approximately 30, capacitively
distributes the field that surrounds the termination.
Electrical flux is refracted to distribute the voltage stress
in a controlled manner along the entire termination length
extending beyond the cable shield cutoff. By controlling the
electrical field, the stress concentrations within the installed
termination and on the termination insulator surface are
kept below 15 volts per mil at rated voltage. Within a 15 kV
cable, the stress concentrations in a continuous length of
shielded cable are typically 50 V/mil adjacent to the shield
to about 70 V/mil at the conductor. The QT-II termination is
designed to reduce cable stresses at the termination to less
than those in the continuous shielded portion of the cable.
The figure below illustrates an actual computerized stress
plot of the QT-II termination.
cCAUTION
Working around energized electrical systems may cause
serious injury or death. Installation should be performed
by personnel familiar with good safety practice in handling
electrical equipment. De-energize and ground all electrical
systems before installing product.
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•
•
Insulation
Semi-conductive
Insulation Shield
Figure 1
3
Cold Shrink
Silicone Rubber Termination Kit QT-II
5620K Series, for 5–15 kV
Data Sheet