Repairing distribution cable and conductor without a shutdown
A torn jacket on a live feeder does not have to become an outage. It also does not stop being a live cable.
What no shutdown actually buys you
Water finds a nicked jacket long before anybody reports a fault. It travels under the sheath, reaches the armour and corrodes it out of sight. By the time the feeder trips, the job is no longer a jacket job. Stopping that sequence is the only reason to carry repair sleeves on a van.
A wraparound sleeve closes around the cable where it lies. Nothing is cut, nothing is unbolted, nothing is drawn back out of the duct. The manufacturer's published wording is that a system shutdown is not required for the repair.
Read that narrowly. The part removes the outage. It does not remove the permit. Work on or beside an energised feeder is still live work, and the rule that governs it belongs to your network, not to a datasheet. Heat has to be applied at the working position, so a hot-work clearance is part of the same conversation.
Two code ranges cover distribution sizes. GMRS runs from 5 to 192 mm cable outside diameter. GWS, badged Insulsleeve, covers 10 to 200 mm. Between them they take most LV and MV distribution cable in the ground. The web chart and the PDF chart do not agree row for row, and the size chart sets out where.
The seal is a hot melt adhesive lining, published as giving environmental sealing to IP68 once the sleeve has recovered. Read the boundary on that number. It describes water kept out from the moment the bond cools. It says nothing about water that already tracked past the damage last monsoon. Dry the run first, or at least establish how far it went.
The wall is flame retardant and self-extinguishing. Outer-wall operating temperature is quoted as -55 °C to +125 °C. The method is IEC 216.
Triage the damage before anyone orders a part
Three levels, looked at in this order. Only the first one is a repair sleeve. The triage below is this reference's own and the manufacturer publishes no equivalent. Where a kit instruction sheet or your own repair standard says otherwise, that document governs.
Level 1: jacket only
The outer sheath is split, gouged or burned through. Bedding, armour, screen and cores are untouched underneath. Measure the cable outside diameter and the length of the damage, then read those two figures off the chart. This is the repair sleeve's whole job. The manufacturer's own application list is damaged cable jackets and retrofit protection of connections.
Level 2: into the insulation or the screen
Bedding, armour strands, semiconducting screen or core insulation is showing. Stop there. A sleeve seals over a layer. It does not rebuild one, and it restores no screen continuity. Specify a joint, and treat the cable as faulted until it has been tested.
Level 3: loss of conductor section
Strands are cut, melted or missing. The cable has lost current-carrying metal at that point, and no sleeve puts it back. That is a cut and a joint, or a fresh length, depending on how far the damage runs.
GMRS and GWS, closure by closure
Both fold around a cable already in place. What differs is how the seam is held while the heat goes on. In a flooded trench that difference decides which one a crew can actually close.
| Property | GMRS repair sleeve | GWS Insulsleeve |
|---|---|---|
| Codes | GMRS-19 to GMRS-250 | GWS-55/8 to GWS-240/50 |
| Cable OD covered | 5 to 192 mm | 10 to 200 mm |
| Seam held by | Heat-resistant tape wrapped over the fold | A stainless steel channel zipped along the seam |
| Sleeve length | 100, 200, 300 and 400 mm | Up to 1500 mm |
| Recovered wall | Not on the selection chart | 2.7 mm |
| Minimum overlap | 25, 50 or 75 mm by size | Not on the selection chart |
| Shrink ratio | 3:1 | Not stated; the chart gives supplied and recovered diameters |
| Shrink-complete indicator | None published | Temperature-sensitive paint changes colour |
A sleeve does not make bare conductor touch-safe
Say this out loud before the van leaves. A wraparound repair sleeve is a jacket part for insulated cable. Shrunk over bare overhead conductor it is not a touch rating and not a reason to reduce an approach distance. Retrofit covers for bare overhead line are a separate product family, and this reference holds no selection data for them. Do not size one from the charts here. The repair sleeve's own electrical figure is a dielectric strength above 15 kV/mm. The method is ASTM D2671. That is a property of the polyolefin. It is not a voltage class for the cable you repaired.
Where this is the wrong part
Refuse the repair and raise a joint when any one of these is true. The list is written so a supervisor can sign against it.
- Bedding, armour, screen or core insulation is exposed. The sleeve seals over a jacket and rebuilds nothing beneath one.
- A conductor strand is cut, melted or missing. Section loss is a joint, never a sleeve.
- Cable outside diameter falls outside 5 to 192 mm for GMRS, or outside 10 to 200 mm for GWS.
- The damage is longer than the sleeve you can get onto it. GMRS lengths stop at 400 mm. Insulsleeve is available to 1500 mm.
- The published overlap cannot be achieved. GMRS-19 to GMRS-70 want 25 mm, GMRS-115 and GMRS-160 want 50 mm, GMRS-180 and above want 75 mm.
- The bond area cannot be brought clean and dry. Hot melt seals a surface. It does not push standing water out of the way.
- You cannot reach the full circumference. A cleat, a bend, a duct mouth or a wall penetration that blocks the underside of the cable blocks the closure.
- No flame is allowed at the working position. Both ranges recover with heat, and neither datasheet publishes a flame-free method.
Where to go next
- Heat shrink sleeve size chartEvery GMRS and GWS row, and the places the two published charts disagree.
- Wraparound cable repair sleeveThe part on its own: construction, the closure, and what the seal is claimed to do.
- How to install a wraparound heat shrink sleeveSurface preparation, the overlap, and reading the colour change.
- Why wraparound sleeve repairs fail in the groundWhat a rushed seam does two winters later.
- Wraparound or tubularThe one question that decides it when a cable end is available.
- Insulsleeve on the manufacturer's siteGala Thermo Shrink Pvt. Ltd. of Mumbai manufacture both ranges.
- Heat shrink cable repair sleeve, manufacturer's pageThe GMRS application list and the material figures quoted above.
- Wraparound sleeve datasheet, PDFBoth selection charts on one sheet, Issue 2 of October 2024. It adds GMRS-565, GMRS-628 and GMRS-785, repeating the 60 to 132, 65 to 150 and 75 to 192 mm bands under new codes. Quote the code you were given, not the band.
Send the three numbers that settle it
Cable outside diameter in millimetres, the length of the damage, and what is visible at the bottom of it. Add the voltage class, and say whether the run is buried, in a duct or in air.