Advantages of Cold Shrink Technology Over Heat Shrink Technology

After heat shrink products are installed, they should not be moved or bent, as this can compromise the environmental seal or the insulation-to-insulation interface for products. The crystalline regions in the heat shrink material make it very rigid and hard and prevent it from being able to shrink onto the cable or from exerting any inward pressure. EPDM Rubber Silicone Cold Shrinkable Tubing Insulation can be bent up to the maximum bending radius of the cable and will continue to exert inward pressure on the cable and continue to perform. Heat shrink medium voltage accessories typically may be installed in many more pieces than comparable cold shrink accessories. This may lead to more installation errors as there are more pieces to misplace or forget to install. Also, these additional pieces add to the installation time, which is considerably longer for heat shrink products than cold shrink products. 

After about 8-10 years, heat shrinkable tube may cause an interface issue on medium voltage accessories. People used large heat shrink splices in an aerial application (because cold shrink splices were not available in a size that would accommodate their extra-long connector), but after 8 years in service, frequent failures in the form of flashes down the interface would occur in cold weather. 

Heat shrink products must be heated uniformly all the way around to get a good installation and to make sure all the mastic flows properly to provide a seal. When heat is applied to heat shrink materials it can be unevenly heated, like from the front side or top side only, due to tough working conditions, experience of the installer, a tight cable compartment or other constructions and cables, that are in the way for the torch. This results in burning marks, significant insulation wall thickness differences, but also hot melt adhesives and mastics that are not activated due to lack of heat through the heat shrink material. Once a heat shrink accessory is installed, it must not be bent because the seal could be compromised.  

Cold shrink accessories are typically a one piece rubber design that shrink on to the cable when the support core is removed. The installation is easy and simple, as aligning the accessory in the correct position and removing the support core is all that is required. 

When the accessory is positioned, removing a few additional wraps of the support core will secure the accessory. The best way to remove the support core is to move the end of the core around the cable counterclockwise and then apply a short pull. This method keeps the support core away from the cable and connector or lug