Cable terminations from 1.1 kV to 36 kV

Termination, joint, gland — three different operations

A termination ends a cable at a bushing, a lug or an overhead line, and hands the electric field over to air. A joint connects two cable ends and rebuilds insulation, screening and mechanical protection through the splice. The manufacturer names the families separately: GLT, GXO/E, GXOS/E and GPO/E terminate; GXLT, GXS, GXSS, GPS and GTJ joint. The two put side by side.

A gland is the third thing, and it is mechanical. It anchors armour and seals the sheath at an enclosure wall; it does nothing about electrical stress. An armoured extruded kit does include an adhesive-lined gland sleeve, but as one item among a dozen. Short answers to the definitional questions.

Cutting the insulation screen back crowds the equipotential lines at the cut edge, and the tangential field along the insulation surface rises sharply. Two answers exist: lengthen the path geometrically with a stress cone, or redistribute the field with a high-permittivity material. The material answer is Insultube-Stress, a radiation cross-linked polymeric tube rated to 36 kV, operating from −40 °C to 100 °C, minimum shrink temperature 100 °C and fully shrunk at 130 °C. The mechanism, then the product.

Creepage is the other half, and it is settled in air rather than inside the cable. Rain sheds add shed rings so the surface path lengthens without the tail lengthening with it — published as no tracking, erosion or flame failure up to 3.25 kV for 20 minutes [ASTM D2303], dielectric strength 15 kV/mm minimum [ASTM D149], continuous operation −40 °C to +110 °C [IEC 216]. Shed count is published per class on the single-core GXOS/E series: outdoors 2 at 12 kV, 3 at 24 kV, 4 at 36 kV; indoors none at 12 kV, 1 at 24 kV, 2 at 36 kV. How a site's pollution severity maps onto that count is not published — ask the manufacturer.

One caution before those figures are quoted in a specification. AC and impulse withstand are consistent across the kit sheets; the DC withstand durations are not. The same 48 kV, 96 kV and 144 kV appear against 1 minute, 15 minutes and 30 minutes on different sheets. The type-test table reports both sides rather than averaging them away.

This is a reference, not a factory. Every kit, sleeve, shed, boot and connector described here is manufactured by Gala Thermo Shrink Pvt. Ltd. at Palghar, Maharashtra and at the Surat SEZ unit in Gujarat, with partial-discharge, high-voltage and general product testing done in-house. The manufacturer's termination index lists which series exist; the job here is choosing between them.