Cable joint or cable termination? What each kit actually does

The decision, and the input data it needs

Two facts settle this before a kit code is written down: what the cable end being worked on meets, and whether it stays enclosed afterwards. Meeting another cable end is a joint. Meeting a bushing, a lug, a busbar or an overhead line is a termination.

A joint puts the cable back the way the cable maker built it — ferrule, insulation, screen, armour or lead-sheath continuity, outer jacketing sleeve. When the crew packs up the field is still inside a cable and no part of the splice sees weather.

A termination does the reverse. It opens the cable, cuts the screen back, grades the field across that cut, then hands the field to air. Both operations sit under one heading in the manufacturer's index of heat shrinkable cable joints and terminations, which is where the confusion in the search box begins.

Why the air interface is the harder half

Everything a joint resists is bounded: buried or ducted, its temperature swing the cable's own, its mechanical load carried by the joint case. The test conditions say so. GXLT/GPLT is given AC 3.5 kV and 6 kV held 5 minutes with the joint immersed in water; GLT-1100, covering the same two voltages, is tested dry at 4 kV and 8 kV for 15 minutes.

A termination has no such boundary. Once the field crosses into air a surface holds it off, and a surface ages — it wets, it collects salt and cement dust, leakage current dries bands into it, and tracking starts at the driest band. Two components exist for that alone: the non-tracking weather-resistant sleeve and the rain shed, which lengthens the leakage path without lengthening the termination.

The screen cut-back is the shared problem. Cutting a metallic screen concentrates the field at the cut edge, so both families carry stress control tubing and mastic for it. Everything else in the two boxes diverges.

Straight-through, transition, and where joints are covered properly

A straight-through joint sees one cable construction on both sides. A transition joint sees two, and on a requisition that is the only difference worth writing: GTJ/1112 to 12 kV, GTJ/2436 for the 24 kV and 36 kV classes, PILC facing XLPE, with a barrier-type inline connector, stress relief mastic and an oil barrier sleeve where the paper side needs one. It remains a joint, and cannot stand in for a termination at either end.

Joint kit codes, conductor ranges and component counts are deliberately not tabulated here. They are set out for the GXLT, GXS, GXSS, GPS and GTJ series on cablejointkit.com, a sister reference from the same publisher working off the same manufacturer's catalogue; this page carries only the boundary.

The gland is neither

A gland is a mechanical fitting: it anchors the cable at an enclosure wall, terminates the armour and seals the sheath entry. It grades no field, adds no creepage and restores no insulation, so no kit code in either range is a gland size. Exactly one gland-named item appears in the published kit contents of either family — the adhesive-lined gland sleeve supplied with GXOS/E-1236 for armoured single-core cable, and it seals rather than clamps. On the 3-core kits a constant force spring or worm drive clip picks the armour up and a tinned copper braid carries it away. Schedules write glanding and termination on one line because the jobs fall in the same hour, not because they are one product.