Insulation
Okonite's impregnated paper insulation consists of the finest electrical grade paper made
from coniferous wood pulp and the purest grade polybutene dielectric fluid. The paper is
manufactured to Okonite's specifications to produce the necessary mechanical and physical
properties to resist tearing and wrinkling during manufacture and subsequent handling
during installation conditions; and in addition, to assure properties of low dielectric
loss with high dielectric strength. Okonite pretwists the sectors of 3/C cables before
taping to virtually eliminate wrinkles at the cabling machine. To maintain a smooth,
wrinkle-free precisely gapped tape insulation, Okonite carefully slits its own taping pads
into widths tailored for each conductor size and wall thickness. Most important, Okonite
has the latest taping machines with the most precise tape tension controls available
today. The impregnating fluids used are of medium viscosity (high viscosity optional)
polybutene types, also manufactured to Okonite specifications. 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 out of the paper tapes. Okonite's impregnation facilities
clay-filter and degas the dielectric fluids to provide low power factors and stable
ionization levels from voltage stress.
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 encapsulation of the
impregnant. All lead sheaths have the inherent capacity for substantial electrical
conductivity, even 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 of extrusion. 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 aids pulling
through ducts and conduits.
Applications
Okonite Paper Insulated Lead Covered 3/C cable is recommended for use in underground
ducts, direct buried, and aerially when lashed to a messenger. PILC cables are used in any
circuit that requires the highest reliability, the longest uninterrupted service life, and
where the greatest surge, impulse and AC dielectric strength is desired. An added
advantage is that a 3/C PILC cable permits the largest amount of power to be transmitted
in the smallest diameter space because of its unique triangle shaped and nested design.
Although not shown as an insulation above 600 Volts in the National Electrical Code, it
is readily approved for use by local inspectors because of its extensive safe use by
utilities. Therefore, PlLC cables can be used in industrial or commercial applications
with prior notification 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
Pre-twisted conductors. 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 to environment. |