ABB Installation Products 756LR-J0270 35kV 600 Series Deadbreak Elbow with Test Point (with Insulated Plug, Cap, Stud, Lug and…

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How to Install 756LR/776LR Deadbreak Elbow Connectors

This guide provides detailed instructions for the safe and proper installation of 756LR and 776LR deadbreak elbow connectors on 35kV class systems, including cable preparation, lug crimping, and connection to mating apparatus. Ensure all apparatus are de-energized before starting.

Estimated time: 1h 30m

1. De-energize Apparatus and Inspect Parts

   DANGER: Ensure all apparatus in the work area are de-energized during installation or removal of any parts. Do not touch or move energized products. This product should only be installed by competent personnel trained in high voltage safety practices. Inspect all parts for damage, correct rating, and compatibility with mating components.

2. Prepare Cable Position and Clean Jacket

   Position the cable in its final assembled location, ensuring enough slack to provide adequate clearance for removing the elbows. Cut the cable 1-3/4 inches (45mm) from the centerline of the mating product. Clean the outer jacket of the cable for a distance of 24 inches (610mm).

3. Prepare Cable Ends

   Follow the specific instructions supplied with any grounding device or cable shield adapter (e.g., 20MA, 21MA, 600ECS, 10TL) for removal of the cable outer jacket, shield connection, and grounding. For jacketed and non-jacketed cables, remove the outer jacket (where applicable) and prepare the cable as shown in the provided diagrams, exposing insulation, semi-con shield, and neutral/shield wires to specified lengths.

4. Install Cable Adapter

   Bevel the end of the cable insulation at a 45-degree angle, approximately 1/4 inch (6mm) back. Thoroughly clean, then lubricate the cable insulation, always working toward the semi-con shield. Install the cable adapter, small end first, until it is flush with the edge of the tape marker.

5. Prepare Conductor for Lug

   Remove any protruding cable insulation by cutting it even with the end of the cable adapter. Do not cut or nick the cable adapter or the conductor. Verify the length of the exposed conductor is between 4-3/8 inches (111mm) and 4-3/4 inches (121mm). If not, redo the assembly.

6. Crimp Compression Lug

   For copper conductors, fully insert the conductor into the compression lug. For aluminum conductors, wire brush the conductor and immediately fully insert it into the compression lug. Measure the “Check Dimension” before crimping; it should be less than 7 inches (178mm). Crimp the compression lug following its supplied instructions. Wipe all excess inhibitor from the compression lug and cable adapter surface after crimping. Verify the distance from the end of the compression lug to the cable adapter after crimping is between 6-7/8 inches (175mm) and 7-5/8 inches (194mm). If not, redo the assembly.

7. Install Elbow onto Cable Adapter

   Lubricate the cable adapter and the inside of the elbow cable entrance. Install the elbow onto the cable adapter until the elbow cannot advance further. Make sure the cable adapter is still flush with the tape marker. If not, reposition the cable adapter. Remove the tape marker.

8. Connect Elbow to Mating Part

   DANGER: Do not connect or disconnect mating products while energized. Do not energize while disconnected. Remove protective caps from both the elbow and the mating part. Hand tighten the threaded stud (supplied with the elbow) into the mating part if it is not already equipped. Clean and lubricate both the elbow and the mating part with the supplied lubricant, keeping surfaces clean. Push the elbow onto the mating part, lining up the hole in the compression lug with the stud on the mating part.

9. Connect Opposite Mating Part (if applicable)

   Clean and lubricate the mating part for the opposite end of the elbow. Insert this mating part into the elbow. Engage the threads and hand tighten. Torque the mating part according to the instructions supplied with that specific mating part.

10. Install Insulating Plug and Cap (if used)

    If an insulating plug is used as a mating part, clean and lubricate the inner surface of the voltage detection cap. Place the cap on the elbow and push down hard until it snaps into place. CAUTION: The insulating plug provides a means for detecting system voltage; follow voltage test directions.

11. Ground the Cable Shield

    Insert one end of a piece of wire with ampacity at least equivalent to No. 14 AWG Copper through the grounding eye and twist to make a small loop. Do not damage the eye. Connect this wire to ground using a suitable connector. The shield of the cable must be grounded according to the instructions supplied with the grounding device, or through an alternate method if no grounding device is used.

12. Waterproof Cable Jacket and Perform Voltage Test

    It is recommended that the jacket of the cable be waterproofed at this point to prevent moisture from entering the cable. For voltage testing, remove the test point cap with a hotstick (peel off at an angle). WARNING: The voltage test point is a capacitance device, not directly connected to the conductor. Use a suitable sensing device made for capacitive test points. Do not use conventional voltage measuring equipment. Treat the elbow as energized until a 'no voltage' indication is confirmed by other means. After testing, clean and lubricate the inside surface of the cap with silicone lubricant and replace it on the test point.

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