Published in the August 2006 American Longwall Magazine

A compact, 50-pound portable unit, the Fault Wizard uses time domain reflectometry (TDR), or radar, to locate problems in the line that cannot be easily found by sight.

The TDR technology is not new, according to company representative Mike Lester of Skaff Engineering, but the way in which the unit operates to quickly find problems and let the operator know about them, is.

Cable troubleshooting begins with simple connections to an isolated cable. The Fault Wizard then sends a pulse down the cable to the problem and reflects back, giving the unit its data and an easily-read distance to the operator.

“We can figure out distance to open circuits, arcing faults, and dead shorts … very accurately, within a few feet,” Lester said. When the information readout appears on the screen, a sound is produced at the problem area – often loud enough to be heard over working equipment – that directs the user to the precise fault point.

From that point, Lester said, work can resume very quickly. “You shut the machine down, fix the bad cable, and you’re back in production, instead of hunting for that cable fault for hours or … sometimes more than a shift.”

The Fault Wizard is able to do low- and high-voltage tests and has a capacity of 10 kilovolts (good for cables up to 35kV rated), which Lester notes will not cause damage to a cable in good condition. Additionally, the unit can work on a cable up to 10,000 feet in length.

The unit is battery-operated and can be stored underground when not in use – both conveniences to operations that need answers quickly and efficiently. Additionally, the Fault Wizard is constructed to always be at the ready – Lester said there are more than 200 units in use now at coal operations.

With longwall faces getting wider, another advantage of the unit is its ability to be used at the headgate or tailgate, though Lester notes typical use is at the former. No matter the location, when the need arises, its user-friendly design ensures anyone at the face can be quickly trained to use it, he added.

While the unit has been on the market for nearly half a decade, Lester said he is always happy to see the units going into more mines and that operations can be confident in its performance.

“The Fault Wizard has a one-year warranty. We perform any needed repairs in a prompt timeline, often within days. The manufacturer stands behind this machine.”