Cable Replacement, Splicing & Terminating : A Video Tutorial
Published 19 Sep 2019
The following article has been republished with kind permission of Martha Davis (Senior Director of Content – T&D World and Utility Analytics Institute) from Transmission & Distribution World and their video sponsor Burns & McDonnell.
Burns & McDonnell is a full-service engineering, architecture, construction, environmental and consulting solutions firm, based in Kansas City, Missouri.
Participating Utility: Kansas City Power & Light (KCP&L).
Transmission & Distribution World’s mission is to provide utility executives, managers, engineers, supervisors, operators and linemen with must-read information on:
- Maintenance of the Electric Power-Delivery Systems
This includes an in-depth understanding of transmission, distribution, substations, automation and power flow control.
Want to learn how to perform tasks in the field?
T&D How videos are real-life and shot-on-site, showing transmission and distribution crews and cable splicers at work.
The cable replacement project begins
Video: Kansas City Power & Light (KCP&L) crews begin a cable replacement project at the Meritex Caves in suburban Kansas City.
In Part 1, the crew installs new cable between an above-ground enclosure and a three-phase distribution pole. The linemen crew in the bucket truck prepare a copper cable feed from overhead to underground – a boom is used to enable a vertical cable lift by attachment to a wire mesh Kellem cable grip. The cable pull positions the cable onto the pole. An Altec cable pulling frame supports the cable pull into the underground cable duct.
Video: In Part 2 we watch crews install a new di-electric switch in the caves below ground and pull cable from above ground, then create new splices into the switch.
See the engineers use “noisy sticks” to provide electrical safety check procedures for voltage detection and isolate the high voltage switching cubicles. The solid-dielectric-in-air fault interrupting switch is positioned for the cable splicer to commence cable termination.
The cable termination process starts with the “tamping down” of the neutrals prior to sliding on the cold shrink tube and separable tee-connector cable termination. Semi-conductor insulation is peeled back and cable insulation cut away with the aid of a heat shrink gas torch to soften the insulation layer. Compression style crimp lugs are terminated onto the cable using battery crimping tools as the cable is connected to the switch.
Video: In Part 3 a splicing crew installs new splices at the enclosure feeding power from the distribution pole to the caves underground.
See the cable splicer working 6 cables into the enclosures from the pole – peeling back the cable outer jacket on the concentric neutrals and installing protective water-sealing mastic and cold shrink. Clearances are measured and heat source used to expose cable imperfections, such as cuts, which can then be located and removed by sanding.
The medium voltage cable is terminated to the neutral busbar using separable elbow tee-connectors. Dummy caps are installed and used to test the ground wires.
3m scotch tape for electrical insulation
Video: In Part 4 crews go up on the distribution pole to create new splices and secure the grounding wire.
The distribution pole has been re-cabled and ready for connection as the cable phases are designated A, B and C by the linemen/splicers and prepared for termination.
Watch the electrical taping techniques of the experienced cable jointer using 3M Scotch 33 tape to provide electrical insulation layers to the cable – neutral tails are taped up and switches opened up to begin the cable connection.
closing the switches
Video: In Part 5 the crew adds jumpers and closes the switches to energise the line, bringing power from above ground to 80 feet under in the Meritex Caves, using new and larger cable to meet increased electrical demand.
Watch the linemen and cable splicers “running the tops”, use “pelicans” (hotline clamps) and wire brushes to clean thoroughly. Fault indicators are applied and “beat-on” wedge connectors installed by hammer. The “pelicans” are connected to the switch pins and a drop-out wire installed down from the arrester. Lastly, cable tags are used to provide identification to the medium voltage cables allowing energisation of the cable once switches are closed using switch sticks.
THORNE & DERRICK
Thorne & Derrick are national distributors of LV, MV & HV Cable Installation, Jointing, Substation & Electrical Equipment – servicing businesses involved in cabling, jointing, substation, earthing, overhead line and electrical construction at LV, 11kV, 33kV, 66kV and EHV. Supplying a complete range of power cable accessories to support the installation and maintenance of low/medium and high voltage power systems:
- Slip-on Cable Terminations
- Cold-shrink Cable Terminations
- Heat-shrink Cable Terminations
- Cable Joints – Heat & Cold-shrink
- Separable Connectors (Euromold)
- Surge Arresters & Switchgear/Transformer Bushings
Key Product Categories: Duct Seals | Cable Cleats | Cable Glands | Electrical Safety | Arc Flash Protection | Cable Jointing Tools | Cable Pulling | Earthing | Feeder Pillars | Cable Joints LV | Joints & Terminations MV HV