Heat Shrinkable Low Voltage Breakouts
Heat shrinkable low voltage breakouts designed to provide effective electrical screening, insulation control, and environmental sealing at cable crutch areas in multi-core cable terminations and joints.
Crutch Sealing and Screen Continuity for LV Cable Systems
Low voltage breakouts are heat-shrinkable moulded accessories fitted at the crutch of multi-core LV cables — the point where individual cores fan out from the main cable body. Applied over the prepared crutch, the breakout recovers under heat to form a dimensionally accurate, sealed transition that insulates, mechanically reinforces, and moisture-seals the cable crutch area.
For screened LV cables, semi-conductive breakouts maintain continuity of the cable's electrical screen across the crutch — preventing stress concentrations at the screen cutback point and ensuring screening integrity is preserved through to the termination. Two variants cover the full LV range: standard insulating grade for unscreened cables, and semi-conductive grade for cables with copper tape or wire screens.
- Material Crosslinked Polyolefin
- Voltage Up to 1 kV
- Shrink ratio 3:1
- Variants Standard and Semi-conductive
- Configurations 2-core, 3-core, 4-core
- Flame retardant Yes — IEC 60332-1
- Halogen-free Yes
Why LV Breakouts Are Specified
Covering insulation control, screen continuity, and environmental sealing requirements across the full range of LV cable crutch applications.
Electrical Insulation and Sealing
Crosslinked polyolefin body provides continuous insulation across the crutch zone — protecting conductor cores from mutual contact and preventing insulation breakdown at the transition between the cable body and individual cores.
Semi-Conductive Screening
Semi-conductive grade maintains electrical screen continuity across the cable crutch for screened LV cables — suppressing stress concentrations at the screen cutback point and preserving the integrity of the cable's screening system through to the termination.
Moisture and Environmental Sealing
Hot-melt adhesive inner lining activates under heat, bonding to the cable surface and forming a continuous moisture barrier at the crutch — excluding water, condensation, and contaminants from the cable end preparation zone.
Mechanical Protection
Provides structural reinforcement at the cable crutch, distributing mechanical stress across the core separation point and reducing the risk of insulation damage from bending, vibration, or movement at the cable entry interface.
Indoor and Outdoor Suitability
UV-stabilised compound is suitable for both indoor switchgear enclosures and direct outdoor installations — without requiring separate product grades for protected and exposed environments across standard LV applications.
Simple Heat-Shrink Installation
Single heat application from a hot air gun completes the breakout installation — no secondary adhesive, taping, or mechanical clamping required. The adhesive activates in the same pass, minimising installation time at the cable preparation stage.
Material & Performance Data
Reference data for engineering and procurement. Contact our technical team for full test reports or project-specific qualification data.
| Base material | Irradiation-crosslinked polyolefin — standard insulating grade |
|---|---|
| Semi-conductive variant | Carbon-loaded crosslinked polyolefin — for screened LV cable applications |
| Colour | Black (standard) — other colours available on request |
| Shrink ratio | 3:1 (recovered diameter : supplied diameter) |
| Voltage class | Up to 1 kV system voltage |
| Adhesive inner lining | Hot-melt thermoplastic adhesive — factory-applied, activates during heat shrink |
| Flame retardant | Yes — compliant with IEC 60332-1 |
| Halogen-free | Yes |
| UV resistance | Yes — UV-stabilised, suitable for outdoor installation |
| Installation method | Hot air gun (recommended) or controlled-flame propane / butane torch |
| Operating temperature | –55°C to +90°C (continuous service) |
| Core configurations | 2-core, 3-core, 4-core |
Where LV Breakouts Are Used
Installed across LV cable systems wherever crutch sealing, insulation control, or screen continuity is required at multi-core cable ends.
LV Cable Terminations
Primary application at LV cable ends — sealing the crutch area in 2-, 3-, and 4-core cable terminations across indoor and outdoor distribution installations.
Screened Cable Joints
Semi-conductive grade applied at the crutch of screened LV cables — maintaining screen continuity at the joint and preventing stress concentrations at the screen termination interface.
Switchgear Connections
Cable entry sealing at LV switchgear, distribution boards, and panel enclosures — providing a clean, sealed crutch at the cable termination point within the equipment enclosure.
Transformer Connections
LV cable-to-transformer terminations in distribution substations and pad-mount transformer installations — indoor and outdoor environments at the secondary terminal connections.
Industrial Electrical Systems
Motor, panel, and equipment cable connections in industrial facilities — providing consistent crutch sealing and mechanical protection across multi-core LV cable terminations in plant electrical installations.
Utility Distribution Networks
LV service cable terminations and underground distribution network joints for utility and DISCOM installations — supplied as part of cable accessory kits or separately for site stock.
How to Select the Right LV Breakout
Five parameters determine the correct breakout size and grade. Confirm each before specifying to avoid sizing or grade mismatches.
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01
Voltage Class
Confirm that the cable system operates at LV (up to 1 kV). LV breakouts are not suitable for medium-voltage cable systems — for MV applications at 11 kV and above, anti-tracking grade breakouts are required. For screened LV cables operating near the upper end of the LV range, confirm the voltage class with our technical team.
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02
Standard or Semi-Conductive Grade
Select standard insulating grade for unscreened multi-core LV cables where the requirement is crutch sealing and mechanical protection only. Select semi-conductive grade for cables with a copper tape or wire screen — where screen continuity across the crutch is required to maintain the integrity of the cable's screening system. Confirm whether the cable has a screen from the cable data sheet before ordering.
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03
Number of Cores
Breakouts are available in 2-core, 3-core, and 4-core configurations. The core count determines the internal finger geometry of the breakout body. Confirm the core count from the cable drum label or data sheet — a 3-core breakout cannot be used on a 4-core cable and vice versa.
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04
Cable and Core Dimensions
Measure the overall cable outer diameter at the crutch and the outer diameter of each individual insulated core. The crutch body diameter determines the skirt size and the core outer diameter determines the finger bore. Both dimensions must fall within the recovered diameter range of the selected breakout — use the 3:1 shrink ratio to confirm dimensional compatibility before ordering.
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05
Installation Environment
Standard LV breakouts are UV-stabilised and suitable for both indoor and outdoor installations. For installations in chemically aggressive environments, coastal locations with salt-laden air, or sites with elevated contamination levels, confirm the suitability of the standard grade with our technical team. For outdoor MV applications or heavily polluted environments, anti-tracking grade breakouts should be specified instead.
For screened cables with non-standard constructions, or for projects requiring a specific colour or configuration not listed above, contact our technical team before ordering.
Common Technical Questions
A standard LV breakout is made from insulating crosslinked polyolefin and provides crutch sealing, insulation, and mechanical protection for unscreened multi-core LV cables. A semi-conductive breakout is made from carbon-loaded polyolefin, which has a controlled surface resistivity. It is used on screened LV cables to maintain electrical continuity across the cable screen at the crutch — ensuring the screen is not interrupted at the point where it is cut back. If the cable has a copper tape or wire screen, use the semi-conductive grade. If the cable has no screen, use standard insulating grade.
Using an insulating breakout on a screened cable creates a gap in the electrical screen at the crutch. This breaks the continuity of the screening system and may create an electrical stress concentration at the point where the screen terminates. For LV screened cables, this can lead to progressive insulation degradation at the screen cutback edge over time. Semi-conductive grade bridges the screen termination and eliminates this risk. The correct grade must always be matched to whether the cable is screened or unscreened.
LV breakouts are rated for systems up to 1 kV and are formulated for general-purpose insulation and sealing. Anti-tracking (AT) breakouts are rated for medium-voltage systems up to 36 kV and incorporate a specialised compound that suppresses surface tracking — the formation of carbonised conductive paths under combined electrical stress and environmental contamination. AT grade is mandatory for MV applications because the electrical stress levels involved can cause surface tracking on standard polyolefin. LV breakouts should not be substituted for AT breakouts in MV applications.
No. The hot-melt adhesive is factory-applied to the bore of the breakout. It activates automatically during the heat-shrink process — melting and flowing into the cable surface as the breakout recovers. No secondary adhesive application or taping step is required. Ensure the cable surface at the crutch area is clean, dry, and free from oil or grease before installation to achieve full adhesive bonding.
Yes. The breakout is applied over the prepared cable cores after the armour has been terminated, the bedding cut back, and the crutch area cleaned and prepared per the jointing kit instructions. The relevant measurement for breakout selection is the overall crutch diameter including any remaining bedding or filler, not the armour outer diameter. For SWA cables with a copper screen beneath the armour, confirm whether semi-conductive grade is required based on whether screen continuity at the crutch is specified.
Yes — LV breakouts are UV-stabilised and suitable for outdoor LV cable terminations and joint locations. For exposed outdoor LV installations in coastal, tropical, or heavily polluted environments, contact our technical team to confirm the suitability of the standard LV grade for the specific environmental conditions. For outdoor medium-voltage applications, anti-tracking grade breakouts must be used — standard LV grade is not suitable for MV systems regardless of the installation environment.
Need Help Selecting the Right Breakout?
Speak with our technical team for sizing, application guidance, and product recommendations.