Open End Enquire

In air

An energised end, in air, that the next person must see

The end is at working height, dry, and still connected. The cap has to close it and it has to say so.

What this page does not answer

This is a cable-industry part, fitted with a gas torch by a jointer, on a cut power or control cable end. Capping off a live wire inside a house is a different job under different rules and belongs to a qualified electrician. Nothing here answers it. What the manufacturer publishes for this kit is material data, not a system voltage rating, so read the figures below as what the moulding is made of and not as a licence to leave an end energised.

Live end cap kit, GLEC series

Live end cap kit, GLEC series

A two-stage closure for a cable end that is still connected. Four small inner caps seal the cores one at a time; a thick-wall outer cap then goes over the assembly carrying the flash symbol that identifies the end as energised. Moulded in cross-linked polyolefin by Gala Thermo Shrink Pvt. Ltd. of Mumbai, four sizes, 1.5 to 300 sq mm conductor.

  • Each core sealed separately before the outer cap is applied
  • Thick-wall outer cap marked with a live flash symbol
  • Supplied as a four-piece plus one-piece kit
  • Four GLEC sizes cover conductor from 1.5 to 300 sq mm
  • Dielectric strength 12 kV/mm min., volume resistivity 1 x 10¹⁴ Ohm.cm min.
  • Continuous temperature limit -40 °C to +110 °C
MaterialCross-linked polyolefin
SizesFour, covering 1.5 to 300 sq mm conductor
Kit contentsFour inner caps plus one outer cap
Inner cap codeGLEC 001S
Outer capThick wall, marked with a live flash symbol
Continuous temperature-40 °C to +110 °C
Dielectric strength12 kV/mm minimum
FittingGas torch
ASTM D638ASTM D570ASTM D2671ASTM D149ASTM D257ASTM D150ESI 09-11IEC 216

Two caps, and the order they go on in

The kit closes the end in two stages and the order is the design. Each core is sealed on its own first, with a small inner cap recovered over that core's insulation, so the phases stay individually covered instead of sharing one cavity under a single lump of adhesive. Those inner caps carry the size code GLEC 001S; four come in the kit.

Only then does the outer cap go over the assembled bundle. It is the thick-wall piece and it does three things the inner caps do not: takes the end down to one closed profile, gives it a surface that survives handling, and carries the mark. That is why the kit is counted as four pieces plus one rather than as five caps.

Sizing therefore happens twice. An inner cap is chosen against a single core; the outer cap has to pass over the assembled bundle, not over the conductor size in the cable schedule. Four GLEC sizes cover 1.5 to 300 sq mm conductor, and the dimension tables are read the same way whatever the variant: that method is on the size chart page. The ordering variants sit on the manufacturer's own live end cap page.

The mark is not decoration

A capped end is an anonymous end. Once the cores are covered, an energised end and a spare dead one look identical from three metres away, and the person who arrives next is usually not the person who fitted the cap. The flash symbol carries the information across that handover, and it sits on the outside of the thickest wall in the assembly because it has to stay legible after the end has been dragged over a drum flange, stacked against a wall and left out through a monsoon.

Closing an end and identifying it are separate duties and only one of them is tested. The figures below describe the moulding: how well it insulates, what it withstands, how it behaves after 500 hours hot. None of them says whether the symbol can still be read two years later. Treat the marking as a site control somebody has to look at, not as a property verified once at the works.

The thickness follows from that second duty. The outer piece is the one that gets handled, and a cap that seals perfectly while scuffing its symbol off in the back of a van has done half its job.

What this kit is not for

The wrong reader reaches this page more often than the right one, so the limits come first.

  • Not a domestic wiring part. A consumer-unit tail, a lighting drop or a junction box is outside this range and outside these rules.
  • Not a way of making an energised end safe to approach. It closes the end and labels it. Isolation is still isolation.
  • Not a vent. A sealed end on a hot high-voltage cable can build internal pressure; that is the relief-valve variant on de-gassing end caps, not this kit.
  • Not fitted cold. Every piece recovers with heat, so where hot work is prohibited the decision changes before the part does: see where a torch is not allowed.
  • Not a termination. This closes an end that is waiting. It does not take a cable into equipment.
  • Not the plain sealing cap. Where the end is dead and headed into a duct or a trench, the base Insulcap end cap is the part, and it goes deeper than this one ever will.

Electrical properties

PropertyValueTest method
Dielectric strength12 kV/mm (min.)ASTM D149
Volume resistivity1 x 10¹⁴ Ohm.cm (min.)ASTM D257
Dielectric constant5 (max.)ASTM D150

Published for the cross-linked polyolefin the caps are moulded from. These are material figures, not a rating for the circuit the end belongs to.

Thermal limits

PropertyValueTest method
Continuous temperature limit-40 °C to +110 °CIEC 216
Shrink temperature125 °CIEC 216
Low temperature flexibility, -40 °C for 4 hrsNo crackingASTM D2671
Heat shock, 250 °C for 30 minNo cracking or flowingESI 09-11
Accelerated ageing120 °C for 500 hrsASTM D2671
Tensile strength after ageing11 N/mm² (min.)ASTM D638
Ultimate elongation after ageing300% (min.)ASTM D638

Questions this page gets

Can I use this to cap off a live wire at home?
No. It is a cable-industry kit fitted with a gas torch to a power or control cable end. If the wire is inside a house the work is an electrician's, not a purchase.
Does the flash symbol mean the cap is rated for the voltage on that cable?
No. The symbol identifies an energised end to whoever arrives next. What is published for the moulding is material data measured on a sample: 12 kV/mm minimum dielectric strength, 1 x 10¹⁴ Ohm.cm minimum volume resistivity. Neither is a system voltage rating and neither should be quoted as one.
Can the outer cap go straight over the cores without the inner caps?
The published construction seals each core first, and no single-cap version of this kit appears in the manufacturer's data. Ask before assuming the outer cap alone is equivalent.
The end will stand in a yard through a hot summer. Does that matter?
The continuous limit for the material is -40 °C to +110 °C (-40 °F to 230 °F) and the ageing row above was taken after 500 hours at 120 °C. A stockyard is not the problem. A cable running hot enough to push gas up to the end is, and that is a different cap.

Send the cable make-up, not a part number

Core count, conductor size in sq mm, cable type, overall diameter over the sheath. With those four the reply can name a size instead of asking for them.