Published in the August 2006 American Longwall Magazine

American wire and cable company Amercable said power cables are integral in preventing longwall systems from chewing up coal and spitting out profits, and as system sizes and equipment demands continue to grow, Amercable has expanded to provide complete engineering and technical support for mines.

This includes training mine personnel on the industry’s best practices of cable management and cable handling and splicing techniques on low and high voltage trailing cables.

“We train mine personnel on proper bend radius and proper tensioning for cable handling. For splicing we focus on proper preparation, rebuilding each component originally supplied by Amercable, and on rebuilding the helix of the power and grounding conductors prior to re-jacketing,” the company said.

At a time of record setting longwall faces, Amercable’s Tiger Brand longwall cable, which has extra pull, flex strength and added torsion resistance to help prevent kinking or corkscrewing, has been a popular choice among customers.

“Larger longwall systems also require a larger scale of maintenance, where quick circuit and voltage identification are extremely critical to minimize down time.”

Amercable said there are some common best practices they teach at mines in order to gain maximum efficiency and extended cable service life.

“Cables need to be removed from the factory shipping reel by jacking it up and placing on an axle instead of ‘flopping’ the reel and ‘walking’ the cable off the reel round and round,” Amercable field engineers said.

“Also, pulling continuous miner cables around the ‘rib’ corner under high tension causes a lot of mechanical damage and cuts and abrasions to the jacket. Cables should be gripped in several locations along the length prior to pulling around a rib corner or pulling long lengths straight down the haulageway.”

The company’s Chlorinated Polyethylene (CPE) jacket provides the physical performance and strength needed to resist wear, tear, abrasion and compression cuts caused by everyday mining use and are brightly colored for easy circuit or voltage identification for repair personnel.

For extremely abrasive environments, AmerCable’s Thermoplastic Polyurethane (TPU) jacket provides the extra-tough physical properties needed in the roughest mining environments.

In longwall operating environments where sharp-edged or highly abrasive material is falling on the Bretby chain, many customers are turning to the TPU cables.

TPU’s physical properties in crush, cut-through, and abrasion resistance far exceed those of common thermoset rubber jackets and have five times the abrasion resistance and twice the tear and tensile strength of normal rubber-based materials. It has also passed Mine Safety and Health Administration flame tests for use in underground mining applications.

AmerCable has helped many customers with productivity/handling issues. When a mine in Arizona experienced electrical failures at a high monthly rate, AmerCable introduced them to the TPU jacketing material, held cable handling classes for all employees and conducted splicing classes for all electricians.

The mine changed out all rubber jacketed cables to TPU and, with the classes, reduced electrical failures to 30 per month (an approximate 75% reduction).