3M Cold Shrink Cable Terminations (MV-HV 11kV 33kV 66kV)
Thorne & Derrick distribute 3M Cold Shrink Cable Terminations for medium and high voltage 11kV 33kV 66kV cables and electrical systems – we provide competitive prices for cold shrink cable terminations from extensive stocks to UK and international destinations.
3M QTIII cold shrink terminations conform to the dielectric test performance requirements of international standards including IEEE-48, CENELEC HD629.1 S1 and VDE0278
Also: 3M Cold Shrink Cable Joints for MV-HV cable jointing.
Using cold shrink cable terminations reduces the risk of cable jointer error or causing damage to the insulation of the MV-HV cable.
3M Cold Shrink terminations are available in a Standard QTII range (3M Quick Term II – Partially Integrated) and a Premium QTIII range (3M Quick Term III – Fully Integrated).
Cold Shrink Features & Benefits
- Tight cable sealing – termination retains resiliency and pressure even after prolonged aging and pollution exposure in outdoor locations
- Flexible Cold Shrink – accommodates all power cable manufacturers bend radius tolerances and recommendations
- Reliability – high dry and wet insulation resistance
- Outdoor cable terminations – excellent resistance to to ozone and ultra-violet radiation
- Versatile – Cold Shrink cable terminations install quickly and accommodates a wide range of cable sizes
Cold Shrink Terminations
3M QTII v. 3M QTIII
The following tables and videos demonstrate the specification differences and features of both the 3M QTII and 3M QTIII versions of Cold Shrink cable termination.
|3M QTIII Premium Cold Shrink Cable Terminations||3M QTII Standard Cold Shrink Cable Terminations|
|Fully Integrated Cable Termination||Partially Integrated Cable Termination|
|Moisture Blocking Mastic (1.)|
|Integrated into cable termination||Applied separately|
|Outer Insulation (2.)|
|Very good track resistance||Good track resistance|
|Stress Control Tube (3.)|
|Integrated into cable termination||Integrated into cable termination|
|Silicone Grease-Stress Relief (4.)|
|No – Integrated mastic is sufficient||Yes – Applied separately|
|Stress Control Mastic (5.)|
|Integrated into cold shrink termination||No – Requires silicone grease|
Cold shrink terminations are shown here with the MV HV cable conductors terminated using mechanical shearbolt cable lugs, such as Pfisterer Sicon, however conventional MV HV cable lugs using compression (crimping) technology are also compatible including Cembre type with the apppropriate crimping tools.
*Data based upon U.S. failure data of U.S. manufactured 3M Cold Shrink Medium & High Voltage Cable Accessories between 2009 and 2012.
➡ Read Blog: 3M Cold Shrink Benefits v Heat Shrink
The 3M QTIII Premium range of Cold Shrink offers the greatest simplicity and flexibility, covering a broad range of MV-HV cable sizes and types and accommodating voltages from 11kV up to 66kV/69kV.
As they are fully integrated this reduces the time required to install, reducing scope for cable jointer error and the shorter installation length enables cable termination into a wide range of cable end boxes and switchgear.
Alternatively, the Standard 3M QTII Cold Shrink termination range is partially integrated, providing all the benefits of using cold shrink technology over heat shrink terminations whilst being a viable cost-based option to the fully integrated premium range. The 3M QTII range covers many of the most common cable configurations and conductor sizes unique to the UK medium and high voltage power cable market.
3M QTII Cold Shrink Cable Terminations
➡ Watch Video Demonstration of QTII Cold Shrink Terminations:
Terminating Copper Tape Screened MV HV Cables Using Cold Shrink
Earthing copper tape screens/shielded cables using tinned copper earth braid and constant force springs bonding to MV HV cable.
3M QTIII Cold Shrink Cable Terminations
➡ Watch Video Demonstration of QTIII Cold Shrink Terminations:
Using 3M Cold Shrink To Terminate Cables
|1. Prepare and strip the MV-HV power cable as normal using correct jointing tools and clean with 3M Cable Wipes||2. Place the 3M Cold Shrink termination body over the single or 3 core cable end and position at the correct point on the MV-HV cable||3. Begin to remove the inner core, allowing the 3M termination to cold shrink down onto the cable||4. Once the inner core has been fully removed, the cold shrink cable termination installation is complete|
3M QTIII Silicone Rubber Cable Terminations
3M 7600 range of QTIII Cold Shrink Terminations are designed to terminate 3 core conductor medium/high voltage shielded power cables: 7600-3W Terminations for cables without ground wires and 7600-RJS Terminations cabinet mounted cold shrink kits suitable for MV-HV cables with or without ground wires. QTIII terminations are one piece cold shrink assembly consisting of skirted or tubular insulator body, high dielectric constant (Hi-K) stress control tube, conformable Hi-K stress control mastic with built-in silicone cable lug-sealing compound.
The complete cold shrink termination is pre-stretched and loaded onto a removable plastic core for installation by the MV-HV jointer.
Core removal allows the cable termination assembly to shrink down and seal down and seal onto prepared cable phase insulation and cable lug barrel surfaces.
Material Characteristics Of Cold Shrink
When airborne contaminants are deposited on a Cold Shrink termination surface destructive leakage currents can initiate when the surface becomes wet in both substation or outdoor locations, such as pole-mounted.
Fog and drizzle are normally considered to be worse than rain as these two forms of precipitation can combine with accumulated surface contaminants to reduce surface resistivity and promote leakage current formation. Rain tends to wash the pollutants off the cable termination surface.
3M Cold Shrink silicone rubber 3 core cable breakout boots are hydrophobic; tending to reject and repel moisture accumulation and thereby reducing the probability for discharge-initiated material erosion and tracking on medium/high voltage cable terminations.
Installing the Cold Shrink Breakout Boot
- Slide the Cold Shrink cable breakout boot onto the MV-HV cable from the neck end. Guide individual cable phase legs through the assembly finger cores.
- Remove Cold Shrink boot Neck Core (B) by pulling, while unwinding, the loose pull tab (E) in a counter clock-wise direction around the MV-HV cable.
- Remove each Cold Shrink finger core (A) using the same technique (Step B)
- Cold Shrink cable breakout area is now protected from environmental contamination and moisture.
Severe environmental conditions that are sustained for long time periods can cause any polymeric surface, such as XLPE, to lose its hydrophobicity. Cold Shrink manufactured using EPDM polymers and others tend to lose their hydrophobic nature over time.
Porcelain surfaces become increasingly hydrophilic with time which can result in premature failure or flashover. Silicone surfaces can regenerate their hydrophobic nature. The 3M silicone insulator surface will re-establish its hydrophobic surface within 24 hours.
This unique ability is a major factor for ensuring a long service life of the cable termination.
Pictured: Cold Shrink Terminations manufactured by 3M Electrical shown terminating 11kV polymeric single core power cables to be used as transformer link cables.
Ozone, Heat and UV Resistance
One of the most outstanding physical characteristics of silicone rubber is its retention of desirable properties over the very wide temperature range of -150°F (-100°C) to 600°F (315°C).
While industrial and hazardous area cable termination applications benefit from operating temperature extremes the extremely long life expectancy at moderate operating temperatures is relevant to the stability and reliability of all MV-HV cables and power systems.
The silicone polymer molecular backbone, silicon-oxygen linkage, provides the same strong -Si-O-Si- type bond occurring in quartz, sand and glass. This accounts for 3M Cold Shrink outstanding temperature properties of silicones and their resistance to oxidation by ozone, corona and weathering. Polymer chains from organic rubber materials often have double carbon bond molecular backbones which are quickly cleaved by ozone, light, heat or other influences found in the operating environment.
➡ Should you require customer service or technical support on the selection or specification of LV MV HV Cable Accessories please contact us – view the full range of 3M Cold Shrink Cable Terminations below.