Development of cold-shrinkable joints with silicone rubber sleeve for 110-230 kV XLPE cables

One piece, pre-molded joints have been used all over the world for extra high voltage (EHV) XLPE cables. For those pre-molded joints, ethylene-propylene rubber has mainly been applied for many years. We have succeeded to apply a new cold-shrink technology on those pre-molded joints with using silicone rubber that has lower elasticity, better mechanical properties, such as lower permanent set. With cold-shrink technology, pre-molded sleeves can be shipped expanded onto the carrier pipes. So the jointer needs no tools for assembly at the jointing site and just needs to pull out the string of carrier pipes. All the type tests required on IEC standards 62067 Ed.1 were carried out including water immersion and heating cycle tests on our newly developed 220-230kV cold-shrinkable joints (CSJ) and have shown good performance in all the tests.