Insulation
Okonite's impregnated paper insulation consists of the finest electrical grade paper made
from the highest quality sulfate processed coniferous wood pulp and the purest grade
polybutene dielectric fluid. The paper is manufactured to an Okonite Technical Requirement
to assure the electrical properties of low dielectric loss and high dielectric strength;
as well as mechanical and physical properties to resist tearing and wrinkling during
manufacture and subsequent handling during installation. To maintain a smooth,
wrinkle-free precisely gapped tape insulation, Okonite carefully slits its own tape pads
into widths tailored for each conductor size and wall thickness. Most important, Okonite
uses taping machines with the most precise tape tension controls available today. The
impregnating fluid used is of the medium viscosity polybutene type, also manufactured to
an Okonite Technical Requirement. Polybutene dielectric fluids are better than natural
petroleum based insulating fluids because they resist aging, have lower and more stable
power factor values and possess an inherent tackiness which resists draining of the paper
tapes. Okonite's impregnating facilities clay-filter and degas the dielectric fluid to
provide low power factors and stable ionization levels over a wide range of voltage
stresses.
Sheath & Jacket
Okonite's copper bearing lead sheath provides an impervious barrier from the environment;
in addition, it provides mechanical protection for the insulation and encapsulates the
impregnant. All lead sheaths have the inherent capacity for substantial electrical
conductivity under short circuit conditions without requiring a separate ground. Okonite's
lead sheaths are applied with a continuous lead extruder under the control of a thickness
gauge for uniform wall thickness and concentricity.
The Okolene® jacket provides mechanical and corrosion protection for the
lead sheath and is used in most installations. (Indoor and aerial installations may not
require a jacket.) Okolene is a thermoplastic polyethylene material that resists most
chemicals and moisture; it is unaffected by oils below 60°C and has a low coefficient of
friction which reduces tensions when pulling through ducts and conduits.
Applications
Okonite Paper Insulated Lead Covered 1/C cable is recommended for use in underground
ducts, direct burial and aerially when lashed to a messenger. PILC cables are used in many
circuits where the highest reliability, the longest uninterrupted service life and where
the greatest surge, impulse and AC dielectric strengths are desired.
Although not shown as an insulation above 600 Volts in the National Electric Code, it
may be approved for use by the local inspector because of its extensive safe use by
utilities for over 60 years. Therefore, PILC cables can be used in industrial or
commercial applications with prior notification to and approval by the local inspector.
Specifications
Okonite PILC cables are manufactured in accordance with and meet the requirements of AEIC
CS1-90, 11th edition.
Product Features Polybutene impregnating fluid.
90°C continuous operating temperature. 110°C emergency rating. 200°C short circuit
rating. High impulse strength. Proven service life of over 40 years. Impervious protection
from the environment. |