Damaged cable results in feeder breaker fire

A substantial fire recently broke out at an underground coal mine near the breaker shaft and machine system hydraulics on a feeder breaker, according to a Mines Safety Alert issued by the Queensland Department of Natural Resources and Mines.

No injuries were reported as fire extinguishers and a water hose were used to put out the fire.

Initial site investigations reveal the fire started close to where a rotating shaft had rubbed through a cable containing an intrinsically safe electrical circuit.

A guard protecting the rotating shaft was not replaced after it was removed for maintenance work, and as the cable was not secured properly it allowed them to make contact.

Investigations are continuing to look into the possibility that the damaged electrical circuit generated enough heat to initiate a fire in a build-up of grease, oil, coal and other combustible material.

While all contributing factors to the case have not yet been established, the investigation has so far identified the following recommendations to prevent similar incidents:

• Ensure all guards are correctly installed.
• Ensure electrical circuits, including intrinsically safe circuits and associated cables, are adequately protected and secured to prevent damage.
• Ensure maintenance strategies include regular checking of electrical cabling, including intrinsically safe electrical circuit external cabling.
• Ensure housekeeping practices prevent the build-up of contamination such as oils, grease, coal or other flammable materials in the vicinity of electrical equipment and cabling.