2. Design Lead Team Mr.H.K.Agarwal,C.E.O Mr. A. K. Pal, Sr. General Manager Mr. T. C. Roy, Manager Mr. R.S.Dutta,Sr.Drafts man Mr. Ashim Bhowmick,Sr.Engineer Supreme & Co. Pvt. Ltd.

3. M/s Sterlite Grid Limited faced a problem in 400kV D/C Quad Transmission Line Bongaigon to Siliguri. Un-Compressed zone of Compression type dead end sleeve are elongated in line. One of the supplier incorrectly supplied EC Grade Dead End Sleeve instead of Al.Alloy Sleeve. Conductor Used In Line :AAAC 525 Sq.mm Overall Diameter : 29.79 mm Minimum UTS : 146.03 kN M/s Sterlite Grid Limited faced a problem in 400kV D/C Quad Transmission Line Bongaigon to Siliguri. Un-Compressed zone of Compression type dead end sleeve are elongated in line. One of the supplier incorrectly supplied EC Grade Dead End Sleeve instead of Al.Alloy Sleeve. Conductor Used In Line :AAAC 525 Sq.mm Overall Diameter : 29.79 mm Minimum UTS : 146.03 kN

4. 1. Due to the lower Tensile strength rating of EC Aluminium sleeve, it cant perform that designated mechanical function of dead ending conductors. 2. While the EC sleeve is unsuitable as mechanical component, it will still function perfectly as an electrical component by adequately transmitting current to the jumper. 3. The solution lies in the physical separation of dead end assembly parts into discreet mechanical and electrical components. 4. While the sleeve already installed and this will continue to function as electrical component, we overlay a mechanical component on the existing installation which will allow the line to be tensioned with appropriate factor of safety. 1. Due to the lower Tensile strength rating of EC Aluminium sleeve, it cant perform that designated mechanical function of dead ending conductors. 2. While the EC sleeve is unsuitable as mechanical component, it will still function perfectly as an electrical component by adequately transmitting current to the jumper. 3. The solution lies in the physical separation of dead end assembly parts into discreet mechanical and electrical components. 4. While the sleeve already installed and this will continue to function as electrical component, we overlay a mechanical component on the existing installation which will allow the line to be tensioned with appropriate factor of safety.

5. Q UOTE :9.11.6.1. H ELICAL T ERMINATIONS FOR CONDUCTORS (G REEN B OOK 9-50) Helical dead-ends are used to terminate conductors. They have been used successfully for the past 40 years. The typical device is designed to hold the mechanical load of the conductor and is not designed to transfer electrical loads. Most helical terminations for smaller ACSR and conductors of homogeneous construction (such as AAAC or AASC. The structural reinforcing rod layer is similar to an armour rod layer and increases the contact length of the dead end.

6. The second layer is a helical termination that is wrapped over the structural reinforcing layer. The helical termination is designed such that the bore of the helical wrap is smaller than the diameter of the conductor. This results in compressive force being applied to the conductor along the contact length of the product. The helical termination only contacts the out side layer of the conductor.So it must pass the compressive load into the inner layer of the conductor. In case of multi-layer ACSR,the helical dead end cannot pass enough holding strength onto the core to develop 90% RTS of the conductor. In these cases, specially designed two layer helical termination may increase the holding strength above the 95% RTS level.

7. DRAWING

8. B RIEF T ECHNICAL P ARAMETERS : As suggested in above drawing, we shall use aluminium alloy re-inforcing rods helically wound on conductor so that such re-inforced conductor would be nearly equal to sleeve outer diameter of compressed portion of dead end. Add one more layer high strength aluminium clad steel looped and helically wound dead-end covering the entire length spanning the sleeve and re-inforced portion of conductor. We shall install additional corona-ring of smaller dia of 200 to shield the extended portion. As suggested in above drawing, we shall use aluminium alloy re-inforcing rods helically wound on conductor so that such re-inforced conductor would be nearly equal to sleeve outer diameter of compressed portion of dead end. Add one more layer high strength aluminium clad steel looped and helically wound dead-end covering the entire length spanning the sleeve and re-inforced portion of conductor. We shall install additional corona-ring of smaller dia of 200 to shield the extended portion.

9. G UARANTEED T ECHNICAL P ARTICULAR 1.Maker’s Name & Address : Supreme & Co. Pvt. Ltd. P-200 Benaras Road Howrah 711108 2.Drawing No. :19003/P (Part -14/1) Date: 19.09.2014 3.Protective Helix Material :High Strength Al.Alloy type 6061 4.No of rods per set:13 5.Diameter of rod:7.87mm 6.Length of rod:2080mm 7.Dead End Grip Materials:Al.Clad Steel wire 8.No of rods per set:8 9.Diameter of rod:3 mm 10.Length of Rod :2750 mm 11.Glue & Grit:Used 12.Grading Ring: Extruded Aluminium tube as per IS 733 or IS 1285 or Al.Casting IS 617 Gr 4600 13.Packing :In Wooden Crate

10. EXPERIMENTAL TYPE (D ESIGN ) TEST : EXPERIMENT NO.: 1 (With Out Steel Sleeve) ON A PIECE OF AAAC 525 SQ. MM. CONDUCTOR ONE SIDE COMPRESSED WITH M/S. SUPREME MAKE COMPRESSION DEAD END CLAMP & THE OTHER SIDE WERE COMPRESSED WITH M/S. STERLITE PROVIDED DEAD END CLAMP WITHOUT STEEL SLEEVE. Mechanical Failing Load Test: (i) A tensile load of 139KN (i.e 95% UTS of Conductor) was applied and hold for 5mins. Result : No Slip observed (ii) Load increased up to 161 KN (i.e 110% UTS of Conductor ) and hold for 5mins. Result : Conductor Strand broken down EXPERIMENT NO.: 1 (With Out Steel Sleeve) ON A PIECE OF AAAC 525 SQ. MM. CONDUCTOR ONE SIDE COMPRESSED WITH M/S. SUPREME MAKE COMPRESSION DEAD END CLAMP & THE OTHER SIDE WERE COMPRESSED WITH M/S. STERLITE PROVIDED DEAD END CLAMP WITHOUT STEEL SLEEVE. Mechanical Failing Load Test: (i) A tensile load of 139KN (i.e 95% UTS of Conductor) was applied and hold for 5mins. Result : No Slip observed (ii) Load increased up to 161 KN (i.e 110% UTS of Conductor ) and hold for 5mins. Result : Conductor Strand broken down

11. EXPERIMENT NO.: 2 (W ITH S TEEL S LEEVE ) ON A PIECE OF AAAC 525 SQ. MM. CONDUCTOR ONE SIDE COMPRESSED WITH M/S. SUPREME MAKE COMPRESSION DEAD END CLAMP & THE OTHER SIDE WERE COMPRESSED WITH M/S. STERLITE PROVIDED DEAD END CLAMP WITH STEEL SLEEVE. Mechanical Failing Load Test: (i) A tensile load of 139KN (i.e 95% UTS of Conductor) was applied and hold for 5mins. Result : No Slip observed (ii) Load increased up to 159 KN Result : M/s Sterlite provided Dead End Clamp Broken down from Un- compressed zone. ON A PIECE OF AAAC 525 SQ. MM. CONDUCTOR ONE SIDE COMPRESSED WITH M/S. SUPREME MAKE COMPRESSION DEAD END CLAMP & THE OTHER SIDE WERE COMPRESSED WITH M/S. STERLITE PROVIDED DEAD END CLAMP WITH STEEL SLEEVE. Mechanical Failing Load Test: (i) A tensile load of 139KN (i.e 95% UTS of Conductor) was applied and hold for 5mins. Result : No Slip observed (ii) Load increased up to 159 KN Result : M/s Sterlite provided Dead End Clamp Broken down from Un- compressed zone.

12. FITMENT TEST AT LINE: Protective Helix on Conductor Helically formed Dead End Grip