On site
Making a heat-shrink termination: the sequence, and the tools
Twelve operations in a fixed order, the nine consumables already packed, and the two shrink temperatures the heat has to reach.
The manual in the box overrides this page
This sequence is a reconstruction, assembled here from the manufacturer's published component lists. It is not a published procedure and it is not marked up as one. Every kit ships an instruction manual as a numbered line item, written for one kit code, one cable make-up and one voltage class. Where it differs from anything below, follow it — without exception. What follows is the order those component lists imply, set out so a supervisor can check a delivery before a crew opens it at height.
Four things to settle before the box is opened
The installer's inputs are not the designer's. Cable make-up, cores, mm² and Umax were fixed at kit selection. What decides whether work starts this morning is narrower: the code on the box, the tail the cable box will accept, indoors or outdoors, and how many ends the delivery covers.
Two check in a minute. Outdoor and indoor part numbers differ by one letter — GXO against GXE, GPO against GPE — and nothing on site converts one into the other. The aid table is published as part of the standard kit, so it arrives once per kit, not once per job.
The order of work on an extruded-dielectric termination
Twelve operations, in the order the published component lists imply. Reconstructed here, not published by the manufacturer — the manual in the box is the authority.
Set and mark the tail
The catalogue steps the outdoor tail with voltage across every family: 600 mm at 12 kV, 800 mm at 24 kV, 900 mm at 36 kV, against 450, 550 and 700 mm indoor. The manufacturer's web pages for the two upper GXO/E classes still print the 12 kV figures — check which document the kit was ordered against. Mark before the first cut; the kit holds no spare sleeving.
Clean the working length
Solvent and cleaning tissue are packed for this, and it recurs — before the first cut, after screen removal, and ahead of every adhesive-lined part.
Remove the outer sheath and expose the armour
Positioned by the gland, not by the tail. Bedding and armour below it become the mechanical anchor and the earth path.
Make off the armour or screen earth
Extruded kits earth through tinned copper braid. GXOS/E publishes a constant force spring roll or a solder tack as alternatives for fixing it, which decides the job wherever hot work is barred.
Cut back the metallic screen
Copper binding wire is in the aid pack and this is the step it is usually spent on, though the aid table states no purpose for it. From here the screen edge, not the sheath edge, is the datum for every electrical dimension.
Cut back the semi-conducting screen
Two aids exist for this operation alone: nylon string for cutting XLPE insulation, and aloxite emery tape for lifting semi-conducting residue off the insulation.
Fit the breakout at the crutch
Insulcore-NT on three-core extruded, the semi-conductive GCB series on belted paper cable, Insulcore-LV to 3.3 kV. Sizing runs on diameters, so it was decided at ordering. What selects between them.
Fill the screen step, then recover the stress control tube
Mastic first and tube over it, never the reverse. Minimum shrink temperature 100 °C, fully shrunk at 130 °C — the highest figure in the kit. The grading mechanism.
Shrink the non-tracking weather-resistant sleeve
One per core, over the stress control tube and the bare insulation. GXOS/E publishes it as the anti-tracking sleeve. The four sleeves compared.
Fit rain sheds where the kit carries them
Sheds sit outside that sleeve, and only outdoor kits are published with them. GXOS/E indoor kits carry none at 12 kV, one from 15 to 24 kV and two at 36 kV. Shed count per core.
Crimp the lug
The lug is packed inside GLT-1100 and GPO/E and arrives fitted to the earth braid on GXOS/E. No crimp specification or die number is published against any kit code.
Seal the lug and shrink the terminal sleeve
Lug sealing mastic covers the palm-to-barrel step; the terminal sleeve then bridges lug barrel to core insulation and closes the last opening. GPO/E and GXOS/E call that sleeve adhesive-lined; GXO/E and GLT-1100 do not qualify it.
Where the paper-cable sequence diverges
Two operations move on a GPO/E kit, and both move earlier. The oil barrier sleeve per core and the belting oil barrier over the belt go on before the breakout: they seal impregnating compound below the crutch, and nothing above them can be built first.
The earthing plumb is the second. On GPO/E-1524 and GPO/E-3336 it bonds lead sheath to armour, made before any insulating layer goes down — a plumbed joint cannot be worked through sleeving already recovered over it. At 12 kV the GPO/E list names an earthing lead and no plumb, so that operation may not exist. The full GPO/E component set.
Aids already in the box — do not buy them twice
Nine consumables are published as part of the standard kit, each belonging to a step above. Quantities come from the GTJ/2436 aid table, the only one itemised with counts.
- Cleaning solvent — an installation aid on GPO/E-1112 and inside the GPS/1112 installation kit.
- Cleaning tissue, six pieces, and one mopping cloth — both on GLT-1100 and GXS/1236. The six-to-one ratio shows how often cleaning recurs.
- Aloxite emery tape, three pieces — for semi-conducting residue. The GPS/1112 page calls the same item an emery sheet.
- Nylon string for cutting XLPE insulation, one — the only tool-like object in the pack.
- Silicone grease, three pieces — counted to the core count on the three-core table it is published in.
- Mastic sealing tape, two — cold-applied butyl, a separate line from both the stress control mastic and the lug sealing mastic.
- Copper binding wire, one roll — listed in the aid table with no stated purpose against it.
- Glass cushion tape — classified two ways in the manufacturer's own documents; see the note below.
- Instruction manual, one — the controlling document, written for the code on that box.
Sources disagree — is glass cushion tape an aid or a component?
The GPS/1112 joint page lists glass cushion tape inside the complete installation kit, beside cleaning solvent, mopping cloth, silicone grease and emery sheet. All three GPO/E termination pages list it among the kit components instead. Both are published and no average is taken here. The distinction decides who supplies it: an aid is a consumable counted against the number of ends, a component is fixed by the kit code.
What the published lists do not contain
Read the component and aid lists as a complete statement of what arrives. Everything below is absent from all of them.
- A heat source. Nothing published produces heat, yet no part of the assembly is finished below 125 °C and the graded part wants 130 °C.
- A crimping tool and dies. The lug is supplied; the means of closing it is not.
- Cutting and stripping tools. Nylon string opens XLPE insulation and nothing else. Sheath knives, screen strippers and whatever cuts armour appear in no pack.
- A measuring tape. Published outdoor tails at 36 kV differ by 300 mm between the three-core and single-core series, so nothing here is paced out.
- Earthing hardware beyond the braid. Braid, spring or solder tack and clips are supplied. The earth bar and its fixings are not.
Shrink temperatures that govern the heat
| Component, as published | Shrink temperature | Continuous temperature limit | Method |
|---|---|---|---|
| Stress control tube (Insultube-Stress) | 125 °C in the spec table; 100 °C minimum and fully shrunk at 130 °C in the feature list | −40 °C to +100 °C | IEC 216 |
| Non-tracking breakout (Insulcore-NT, GAB-0820 to GAB-3060) | 125 °C | −40 to +100 °C on the datasheet; +110 °C on the page | IEC 216 |
| Semi-conductive breakout (Insulcore, GCB-0820 to GCB-2755) | 125 °C | −40 to +100 °C on the datasheet; +110 °C on the page | IEC 216 |
| LV breakout (Insulcore-LV) | 125 °C | −40 °C to +110 °C | IEC 216 |
| Rain shed (Insulshed, GRS 130 series) | 125 °C | −40 to +100 °C on the datasheet; +110 °C on the page | IEC 216 |
| Tri-core rain shed (GRST-1 to GRST-3) | 125 °C | −40 °C to +100 °C | IEC 216 |
| Right angle and straight boot (GRB / GSB) | 125 °C | −40 to +100 °C on the datasheet; +110 °C on the page | IEC 216 |
Where a datasheet and the matching product page differ on the continuous limit, both are given. Shrink temperature is what the gun has to reach; the continuous limit is what the finished joint lives at.
Under-shrink is the defect that passes inspection
A softened component and a fully recovered one look the same from a ladder, so heat delivered rather than appearance has to be the acceptance criterion. The manufacturer's answer is a marking: the GXO/E-1524 page states that temperature-sensitive paint changes colour when shrinking is complete, and the 12 kV and 36 kV pages repeat it. No other termination series here publishes it — not GPO/E, not GXOS/E, not GLT-1100.
The kit also sets two heat targets. Every non-tracking part is published at 125 °C [IEC 216]; the stress control tube at 100 °C minimum and full recovery at 130 °C. A pass that satisfies the sheds need not satisfy the tube, and the tube carries the graded field.
Not published — ask the manufacturer
There is no published installation procedure — no method statement, sequence drawing or downloadable jointing document exists for any termination kit in this range. The paint changeover temperature is not published, nor its tolerance, so a colour change is not evidence that a stated figure was reached. Heating times, flame settings and gas consumption are not published. Crimp die numbers and lug torque figures are not published.
What supervisors ask before the crew goes up
Is there a downloadable installation procedure for these kits?
Does the order of work change between an indoor and an outdoor kit?
Which parts carry the shrink-complete paint?
Can the whole kit be shrunk at one setting?
Does a 1.1 kV kit follow the same steps?
Get the manual and the crimp data before the crew mobilises
Quote the kit code from the box, the number of ends, and whether each is indoor or outdoor. Ask for the manual against that code, the crimp die number for the supplied lug, and how many aid packs ship on the order.