Cold shrink cable accessories install in 7–10 minutes per termination. Heat shrink takes 20–25 minutes. The 10–18 minute gap comes entirely from the core shrinkage method—removing a support core versus heating each component for 3–4 minutes. This difference affects project labor, outage windows, and installation consistency.

The Real Numbers — Installation Time Benchmarks

Metric	Cold Shrink	Heat Shrink
Single termination (skilled installer)	7–10 min	20–25 min
Straight joint (two-person crew)	~15 min	45–60 min
Hot work permit required	No	Yes
Post-install cooldown	None	3–5 min per component

These figures are drawn from field measurement records across multiple 10kV and 35kV XLPE cable terminations and straight joints. A two-person crew completes a cold shrink straight joint in roughly 15 minutes—three times faster than a heat shrink equivalent.

Where the Time Gap Actually Lives

Phase 1: Cable Preparation — Identical for Both

Strip the cable jacket, remove the semiconductor layer, clean the exposed insulation, and apply stress control materials for 5–8 minutes, regardless of the accessory type. The stripping dimensional deviation must be controlled within ±2mm; otherwise, the stress cone will not be able to properly overlap with the semiconductive break.

Phase 2: Core Shrinkage — The 18-Minute Divergence

Cold shrink (approximately 60 seconds):

Slide the pre-expanded silicone cold shrink tube over the prepared cable section
Remove the support core by unwinding it counterclockwise
The silicone shrink tubing contracts naturally at ambient temperature—no heat source required

Heat shrink (10–20 minutes):

Each component requires 3.5–4 minutes of controlled heating at 120–150°C
Infrared temperature monitoring is essential to prevent overheating the XLPE layer
Components must cool before proceeding to the next
A typical medium-voltage termination requires heating 3–5 separate components

Phase 3: Final Sealing — Cold Shrink Eliminates the Wait

Cold shrink wrap installation completes with a dynamic “living seal” that expands and contracts with cable temperature variations.Heat shrink materials become rigid after cooling, requiring additional cooldown time before the cable can be moved or energized.

The Hidden Cost — What the Time Difference Actually Means on Site

For a project with 50 terminations, the math is straightforward:

Cold shrink total installation: approximately 6–8 hours (including preparation)
Heat shrink total installation: 17–21 hours
Difference: over 10 labor hours

The impact extends beyond labor. Cold shrink eliminates the need for hot work permits—a requirement that adds administrative delay and restricts installation in hazardous areas.In confined spaces such as cable trenches or tunnels, the absence of heating equipment makes cold shrink the only practical option.

The Installation Mistakes That Don't Make It Into the Brochure

Three Hidden Errors in Cold Shrink Installation

Error 1: Pulling the support core too fast

The cold shrink grip requires steady, continuous core removal. Jerking the ribbon can cause the silicone to snap down unevenly, trapping air pockets against the dielectric.When the stress cone portion is not installed properly, an air gap forms at the interface, leading to failure of the stress control component.

Error 2: Stress cone misalignment

If the stress cone shifts more than 5mm from the screen cutback, the electric field concentration zone no longer covers the semi-conductive break. The result is a 50% reduction in insulation service life.Field installers must verify the center mark alignment within 5 minutes of core removal.

Error 3: Accessory size mismatch

Cold shrink accessories are supplied in specific diameter ranges. A deviation in interference fit—less than 2mm or greater than 5mm from the specified cable insulation outer diameter—compromises both sealing integrity and radial pressure.

A Real-World Failure Case

At one 35kV substation, a cold shrink single-core termination failed within 72 hours of energization. Post-failure analysis traced the cause to incorrect cable preparation dimensions—the semiconductor layer was stripped 8mm beyond the specification. The stress cone could not overlap the semi-conductive break properly, creating a void that initiated partial discharge tracking.Installation quality issues account for over 91% of cable accessory failures in field service.

Beyond Speed — What Cold Shrink Brings to the Table

Constant Radial Pressure

Cold shrink cable accessories maintain continuous radial pressure of approximately 0.08 to 0.15 MPa throughout their service life.This active pressure tracks cable thermal expansion during load cycling—cables heat to ≥90°C during peak demand and cool to ambient temperatures off-peak.Heat shrink, by contrast, forms a static seal that cannot accommodate these dimensional changes, potentially creating micro-voids at the interface.

Silicone cold shrink tube materials exhibit a permanent set of less than 10%—meaning they return to nearly their original dimensions after expansion, maintaining sealing force for decades.

Factory Electrical Testing

Cold shrink accessories undergo 100% factory electrical testing before shipment—partial discharge levels must remain below 5pC at 1.5 × U₀ per IEC 60502-4.Heat shrink components are supplied as untested layers in a kit; failures are only detected after installation in the power network.

Installer Skill Tolerance

Cold shrink installation depends on material elasticity, not jointer technique.The cold shrink grip creates uniform pressure across the entire termination body once the carrier is removed.Heat shrink performance, however, is highly dependent on proper heating technique—uneven heating or trapped bubbles lead to premature failure.

Which One Should You Specify?

Cold shrink is the better choice when:

Outage windows are tight or the project involves emergency restoration
Installation occurs in confined spaces (cable trenches, tunnels, switchgear rooms)
Multiple crews work in parallel with varying experience levels
The site is outdoors or in humid conditions (heat shrink is weather-sensitive)

Heat shrink may still be appropriate when:

Budget is strictly constrained and material cost is the primary driver
Installation team is highly experienced with heat shrink techniques
The site permits open flames and hot work without restrictions
The project involves a small number of terminations where labor savings are negligible

The 18 Minutes Are Real

The 10–18 minute installation gap between cold shrink and heat shrink cable accessories is not a myth. It does not come from cable preparation—that phase is identical for both technologies. The gap lives entirely in the core shrinkage step: cold shrink completes in seconds by removing a support core, while heat shrink requires minutes of controlled heating per component, plus cooldown waits between each.

For engineers planning medium-voltage cable installations, this difference translates directly to project labor hours, outage scheduling, and long-term reliability. The time savings alone frequently justifies the slightly higher material investment when labor rates and project schedules are factored in. Understanding where those 18 minutes hide is the first step toward making the right specification for the job.

8.7/15 kV Fully Cold Shrink Three-Core Terminal – Installation Outline Drawing

Cold Shrink Vs Heat Shrink Cable Accessories: The 18-minute Installation Gap Explained

Electrical Performance Tests

No.	Test Item	Standard Requirements
1	Power Frequency Withstand Voltage	39 kV, 5 min, no breakdown
2	Partial Discharge Test	Partial Discharge Magnitude≤ 10 pC at 15 kV
3	Impulse Voltage Test	95 kV, 10 positive and 10 negative impulses, no breakdown
4	Constant Voltage Load Cycling Test (in Air)	23 kV, conductor temperature 95–100 ℃, total 60 cycles, no breakdown, no flashover
5	Thermal Stability Test (185 mm² Conductor)	23.4 kA, 2 s, twice, no visible damage
6	Dynamic Stability Test	82.6 kA, ≥ 10 ms, no visible damage
7	Moisture Test (Indoor)	11 kV, 300 h, no breakdown, no flashover
8	Salt Spray Test (Outdoor)	11 kV, 1000 h, no breakdown, no flashover

Product overview

◆The product is available in single-core, two-core, three-core, four-core, and five-core versions, and has been widely used for low-voltage cable terminations and intermediate connections.

◆Excellent surface hydrophobicity, ensuring the product maintains strong resistance to contamination.

◆Compact size, lightweight, and reliable performance.

◆Application Scope: The product demonstrates excellent cold and heat resistance, making it particularly suitable for high-altitude, cold, humid, salt-spray, and heavily polluted environments.

Installation requires no open flame, making it ideal for flammable and explosive areas such as petroleum, chemical, mining, and tunneling sites.


8.7/15 kV Single-Core Cold Shrink Indoor Termination – Installation Drawing	8.7/15 kV Three-Core Cold Shrink Outdoor Termination – Installation Drawing	8.7/15 kV Three-Core Cold Shrink Outdoor Termination – Supporting Drawing	8.7/15 kV Three-Core Cold Shrink Joint – Supporting Drawing

Technical Data - Model Selection

Product Type	Model	Conductor Cross-section(mm²)	Product Type		Model	Conductor Cross-section(mm²)
8.7/15 kV Three core cold shrink indoor terminal	GHD-15HNLS-3*25-50	25-50	8.7/15 kV Single core cold shrink indoor terminal		GHD-15HNLS-1*25-50	25-50
	GHD-15HNLS-3*70-120	70-120			GHD-15HNLS-1*70-120	70-120
	GHD-15HNLS-3*150-240	150-240			GHD-15HNLS-1*150-240	150-240
	GHD-15HNLS-3*300-400	300-400			GHD-15HNLS-1*300-400	300-400
8.7/15 kV Three core cold shrink outdoor terminal	GHD-15HWLS-3*25-50	25-50	8.7/15 kV Single core cold shrink outdoor terminal		GHD-15HWLS-1*25-50	25-50
	GHD-15HWLS-3*70-120	70-120			GHD-15HWLS-1*70-120	70-120
	GHD-15HWLS-3*150-240	150-240			GHD-15HWLS-1*150-240	150-240
	GHD-15HWLS-3*300-400	300-400			GHD-15HWLS-1*300-400	300-400
8.7/15 kV Three core cold shrink intermediate joint	GHD-15JTLS-3*25-50	25-50		8.7/15 kV Single core cold shrinkintermediate joint	GHD-15JTLS-1*25-50	25-50
	GHD-15JTLS-3*70-120	70-120			GHD-15JTLS-1*70-120	70-120
	GHD-15JTLS-3*150-240	150-240			GHD-15JTLS-1*150-240	150-240
	GHD-15JTLS-3*300-400	300-400			GHD-15JTLS-1*300-400	300-400

8.7/15kV Cold Shrink Cable Accessories