3M Cold Shrink QT-III Silicone Rubber Indoor Tubular Termination Kits 7640-T and 7650-T Series 5, 8, 15, 25/28 and 35 kV Data Sheet September 2016 Description 3M Cold Shrink QT-III Silicone Rubber Indoor Tubular Termination Kits, 7640-T and 7650-T Series, contain one-piece, non-skirted, silicone rubber terminations, qualified as IEEE Standard 48 Class 1 for indoor and weather-protected applications. The termination assemblies consist of a tubular insulator, high-dielectric constant (High-K) stress control tube, conformable High-K stress controlling compound and built-in environmental top sealing compound. The insulator is made of a dark gray silicone rubber with excellent tracking resistance and hydrophobic properties. The complete assembly is pre-stretched and loaded onto a removable core. The disposable core can be recycled. The kits are designed for terminating solid dielectric Jacketed Concentric Neutral (JCN) and Concentric Neutral (CN) power cables rated 5 through 35 kV. Kit Contents Each kit contains sufficient quantities of the following materials to make one single- phase termination (lugs are not included in kit). 1 High-K , Tracking Resistant, Silicone Rubber Indoor Tubular Termination 2 Strips Scotch Mastic Strip 2230 (black with white release liners, bagged) 1 Instruction Sheet Features Conforms to IEEE Standard 48 Class 1 requirements for 5, 8, 15, 25/28 and 35 kV terminations One-piece versatile design, allowing quick installation and accommodating a wide range of cable sizes Cold shrink delivery system allows easy installation: Simply place termination over prepared cable and unwind core to shrink into place (no force fit required) High-K stress control: Specially formulated high-dielectric constant material minimizes surface stress by more uniformly distributing the electrical field over the entire surface of the insulator Compact design provides for easier installation in restricted spaces Silicone rubber insulators, EPDM stress control tubes, stress controlling compound and environmental sealing compound are compatible with common solid dielectric insulations, such as polyethylene (PE), cross-linked polyethylene (XLPE) and ethlylene propylene rubber (EPR) 1 of 11 3M Cold Shrink QT-III Silicone Rubber Indoor Tubular Termination Kits, 7640-T and 7650-T Series 5, 8, 15, 25/28 and 35 kV Stress Control The 3M Cold Shrink QT-III Silicone Rubber Indoor Tubular Termination Kits, 7640- T and 7650-T Series, controls the electric field stress distribution with special High-K materials, which are an integral part of the termination. The High-K materials, with a dielectric constant (K) of greater than 15, capacitively distribute the field that surrounds the termination. The stress concentrations in a continuous length of shielded cable are typically 50 V/mil adjacent to the shield to about 70 V/mil at the conductor. The 3M Cold Shrink QT-III Silicone Rubber Termination reduces the cable stresses at the termination to less than those in the continuous shielded portion of the cable. Electrical flux is refracted to distribute the voltage stress in a controlled manner along the entire termination length extending beyond the cable shield cutoff. By controlling the electric field, the stress concentrations on the termination insulator surface are kept below 15 V/mil at rated voltage. This stress distribution permits high power frequency performance and impulse performance with a compact termination design. Figure 1 illustrates an actual computerized stress plot of the 3M Cold Shrink QT-III Silicone Rubber Termination. Semi-conductive Insulation Shield Applications The 3M Cold Shrink QT-III Silicone Rubber Indoor Tubular Termination Kits, 7640- T and 7650-T Series, are designed for: 5, 8, 15, 25/28 and 35 kV voltage classes Jacketed Concentric Neutral (JCN) and Concentric Neutral (CN) cables Solid dielectric insulations, such as polyethylene, XLPE and EPR Contaminated and non-contaminated indoor (weather-protected) locations Free-hanging or bracket-mounting arrangements Upright or inverted installations Switchgear, transformer, motor lead, bus and similar connections These terminations can be field tested using normal cable testing procedures (Reference IEEE Standard 400 Guide for Field Testing and Evaluation of the Insulation of Shielded Power Cable Systems.) (Refer to most recent version.) 2 of 11