Reference · definitions, codes and limits

Cable termination questions, answered

Sixteen questions off requisitions and tender clauses, each answered from a published figure or marked as not published.

How to specify a termination kit

Definitions, before anything is ordered

What is a cable termination?

A termination ends a power cable where it meets a bushing, a transformer or an overhead line, rebuilding over the cut cores what the construction supplied along the run: stress control, insulation and a weather seal. In the heat-shrink range that is a named set of parts shrunk on in sequence, not one moulded body. How to specify a kit covers the five inputs that pick the set.

What is the difference between a cable termination and a cable joint?

Count the cable ends. A joint takes two into one sleeve and restores the run; a termination takes one end out to air or into a bushing and stops. The codes keep them apart: GXLT, GXS, GXSS, GPS and GTJ are joints, GLT, GXO/E, GXOS/E and GPO/E are terminations. Side by side on joint or termination.

Is a cable termination the same thing as a cable gland?

No. The catalogue makes the gland a line inside the termination, not an alternative to it: GXOS/E-1236 lists an adhesive-lined gland sleeve for armoured cable separately from its stress control sleeve. The two are not substitutes. Every component in the kit names each part and its job.

What does "end termination of cable" mean?

The same operation under a longer name: what is applied where a run ends, as against a mid-span connection. Nothing is catalogued under that phrase, so a requisition using it still resolves to a series and a kit code — GLT-1100, GXO/E, GXOS/E or GPO/E. Start at the kit hub.

Reading the specification

What does Class I mean on these kits?

It is printed on GPO/E-1112, GPO/E-1524, GPO/E-3336, GXO/E-1524, GXO/E-3336 and GXOS/E-1236, and absent from GLT-1100 and GXO/E-1112. The standards behind the range are published — the catalogue's guaranteed technical particulars are headed in compliance with IEC 60502-4 and CENELEC HD 629.1 — but no document says what the class grades or what Class II would change. Not published — ask the manufacturer for the definition, and quote the withstand figures alongside the two standards: the type-test chart.

How many rain sheds does a termination carry per core?

GXOS/E-1236 is the series that publishes counts: two sheds at 12 kV, three at 24 kV, four at 36 kV outdoors, against none, one and two on the indoor GXES codes. The three-core lists name the shed without a quantity, the exception being GPE-21 to GPE-24 at 24 kV, published as one per core. Selection runs off chart GRS 130-1 to GRS 130-6 — see the shed datasheet and rain sheds.

What is the difference between a GXO code and a GXE code?

One letter, deciding whether sheds arrive in the box and how long the tails are. GXO is outdoor, GXE indoor; the pairing repeats as GPO against GPE on paper cable, GXOS against GXES on single core. Indoor tails run 450 mm against 600 mm on GXO/E, 550 mm against 800 mm on GPO/E-1524. Rest on indoor or outdoor.

What is a type C bushing?

The plug-in interface the screened separable connectors mate to, defined by EN 50180 for bushings on liquid-filled transformers and EN 50181 for plug-in bushings elsewhere. Compliance with both is published across the connector's 11, 24 and 36 kV classes, and the extensible RMU and GIS end sealing kits quote the same interface. It is a geometry, not a rating. Separable connectors carries the withstand table.

What does touch-proof mean, and what does not qualify?

It names the earthed outer conductive screen on a separable connector, so the interface presents an earthed surface rather than live insulation. The evidence published for it is measurable: screen resistance ≤ 5000 Ω, partial discharge ≤ 10 pC at 1.73 U0, every unit factory tested. An insulating cover is a different claim — the GTPE-500 is published as a flashover barrier for tight entry boxes. See cable terminal protectors.

On site, and at the edge of the range

What does stress control do, and why is there none in an LV kit?

Cutting back the insulation screen concentrates the field at the cut edge, and Insultube-Stress is a radiation cross-linked material formulated to redistribute it, published up to 36 kV. With no screen there is no cut edge to grade, which is why GLT-1100 at 1.1 and 3.3 kV carries a terminal sleeve, insulation sleeve, breakout, clamp, earth braid, mastic tape and lug — and no stress control item. See stress control tube and the LV kit.

Can an indoor kit be used outdoors if sheds are added afterwards?

Treat it as a change to the kit, not an adjustment on site. The indoor build is short in two ways at once: no sheds on the GXE and GPE codes, and a tail 150 mm to 250 mm shorter depending on series. The type test is published against the kit as supplied, and a separately ordered shed does not carry that approval. Rain sheds has the charts.

Can one kit be split across two terminations?

No, and the arithmetic defeats it before the approval does. A kit is catalogued as a complete set for one cable end at a stated core count, and the quantities are published against that: a 3-core GXO/E kit holds three terminal sleeves, three stress control tubes, three lugs and one breakout. Split it and the second end is short of a stress control set, a breakout and, outdoors, its sheds. Buy one kit per end.

What is the temperature-sensitive paint on the components for?

It takes the judgement out of a torch pass. GXO/E components carry a paint that changes colour once the part has reached shrink temperature, so a finished sleeve is visible rather than inferred from gloss. The GPO/E, GXOS/E and GLT-1100 lists do not name it, so the completion check there is procedural. Sequence on the installation page.

What is the highest voltage catalogued, and what happens above it?

36 kV. GXO/E-3336 tops the extruded-dielectric range, GPO/E-3336 the paper-insulated one, and the separable connector is published at 630/1250 A up to 36 kV. Above that no heat-shrink termination kit is catalogued, and the 66 kV figures that do appear attach to tube materials rather than to a kit. The 36 kV limit answers the domain name unsoftened.

The commercial questions, answered by refusal

What does a termination kit cost, and how quickly can it ship?

Neither figure is published here and neither is guessed. Price, lead time, stock position and minimum order quantity come from the manufacturer, against a specific kit code and quantity. Not published — ask the manufacturer. Contact sets out the route; the termination listing itself is published here.

What has to be in an enquiry for it to be answered first time?

Ten facts, nine of them already on the cable schedule, listed in full below so this page can be forwarded intact to whoever raises the requisition. The one omitted most often is the bushing type at the equipment end: it decides whether the answer is a shrink-on kit at all or a separable connector. Ask about a termination kit.

The ten lines an enquiry has to carry

Cable insulation: XLPE, EPR, PVC or PILC. GXO/E and GXOS/E on extruded, GPO/E on paper.
Number of cores: Single-core goes to GXOS/E, three-core to GXO/E or GPO/E. GLT-1100 covers 1 to 4 core.
Conductor cross-section, mm²: Picks the code: GXO-21 to GXO-24 spans 16 to 400 mm², GPO-21 to GPO-24 spans 25 to 500 mm².
System voltage and Umax: MV kits group as 12, 24 and 36 kV, so 11/11 kV and 12.7/22 kV both sit in the 24 kV kit.
Indoor or outdoor: The second letter of the code. It moves tail length and shed count, not the withstand figures.
Armoured or unarmoured: Armour brings in the gland sleeve, and on PILC the earthing plumb to the lead sheath.
Screened or belted, on paper cable: Belted PILC needs the semi-conductive breakout. Screened cable does not.
Bushing type at the equipment: An EN 50180 or EN 50181 type C interface moves the enquiry to the connector range.
Lug size and hole pattern: The lug is in the box on GLT-1100 and GPO/E, so the palm must match the stud.
Quantity of terminations: Counted per cable end, not per circuit and not per drum.

Where each of these answers goes deeper

Still blocked on one missing fact?

Send the ten lines above, with a kit code if the requisition carries one. Anything here that a newer datasheet has overtaken is worth writing in.

Ask about a termination kit How this site sources its figures