The World’s First 11KV Longwall Electrical System

Ampcontrol produced the world’s first 11kV Armoured Face Conveyor (AFC) longwall mining system for installation in Zone 1 hazardous areas.

We supplied a full turnkey electrical solution for the project including engineering, manufacture, installation, testing and underground commissioning support.

During the project scoping phase it was identified that the AFC required three electric motors each rated at 1.5MW. To provide this level of power at the current industry standard voltage of 3.3kV would result in significant voltage drop, motor torque reduction and increased short circuit currents which exceed the rating of existing switchgear and would therefore require the installation of impractical, large cables.

Powering three 1,600kW AFC motors, our 11kV electrical system addresses all of these issues and has provided a step change in AFC capacity to deliver increased production rates along with the potential for increased coal face widths which were not feasible using 3.3kV.

An 11kV electrical system for powering the longwall AFC had never been previously used in underground longwall coal mining anywhere in the world and, due to the hazardous zone rating of the mine site, we had to devise electrical equipment that not only performed at the enhanced operating levels of 11kV but were safe in the explosion risk zone.

To meet the challenge, we customised numerous products as well as developed world first 11kV products to suit the application and environment. Critical to the project’s success we had to prove it was safe to use 11kV electrical circuitry in the Hazardous Zone through extensive engineering design review, calculation and verification testing.

As part of this project we developed a new Intrinsically Safe (IS) LED lighting system, an innovative 11kV protection scheme and a SIL-3 rated high integrity isolation system.

Ampcontrol, together with our project partners were awarded a 2010 National Engineers Australia Engineering Excellence Award for this project.