Mine Cable Handling

• The first part of safe mine cable handling is knowing what is inside the cable jacket.

Most mine cable damage occurs due to Mechanical damage:

From the moving / dragging process or from crush and impact.

Driving over the cable, rocks / material falling on / burying the cable.

Excess pulling tension.

Often the cable is damaged internally with no damage showing on the jacket.

The crushed or flattened EPR insulation fails or small strands start to poke through to the shielding causing tripping - to catastrophic failure. The strength of the cable is the strength of the three phase conductors not the jacket. Know the limitations:

Bend Diameters*: •Copper Wire Braid Shielded Cables (Type SHD-GC 2 and 5Kv) = 6 times the cable diameter; •Copper Wire Braid Shielded Cables (Type SHD-GC 8, 15, and 25Kv) = 8 times the cable diameter; •Round non-shielded Cables = 6 times the diameter; *The use of D-Rings, two large diameter ropes, or two wide nylon slings properly attached are recommended for moving these cables.

Pulling Tension: The maximum recommended working tension for portable mining cables, expressed in pounds force: AWG / kcmil 3/C #8 149 lbs. #6 236 lbs. #4 376 lbs. #2 597 lbs #1 753 lbs. 1/0 950 lbs. 2/0 1,198 lbs 4/0 1,250 lbs. / / 500 kcmil 1,250 lbs Cable Abuse Cable Abuse D- Rings A good rule of thumb is to pull no more than 100’ loops Moving cable with a sling. Allow for at least 3 feet between attachment points Couplers should always have their covers on when not in use. And always be cleaned and inspected before use. Un-spooling cable Always pull the cable off the spool allowing the spool to turn on an axle – thereby eliminating any twisting of the cable. If cable is to be moved on a tray or boat – always lay the cable out in a “figure 8”. So the cable will be able to be deployed without any twisting. Loading a cable tray for a tunnel boring machine

Starting the figure 8 Loaded Cable Stands Cable stands are useful as a way to keep cable runs visible Overhead crossings Allow for 10% – 15% “Sag”. Never use a spliced or repaired cable section for an overhead crossing If you have to move an energized cable Use a hot stick and hot gloves In summary:

Use proper spooling techniques in both un-spooling and re-spooling cable to insure that there are no twists and or kinks in the cable. Do not stretch or exceed the rated pulling tension for the conductor size. Do not exceed to bending radius of the cable you are working with. Always stack the cable in a “figure 8” before deployment from a sled. Avoid mechanical damage from driving over the cable or other form of crush and impact. Make sure that the cable is visible when deployed. Look for visible damage on the cable – but remember that cable wears out from the inside as well. Avoid handling energized cable – if you have to move an energized cable use the correct equipment for the task – hot stick / hot gloves. Electrical cable is a very safe and efficient way to transfer energy – but that energy is always attempting to escape. Be safe – lead by example! Thank you for your time!

Cory Hayes TF Cable