Some five years ago, while employed by Joy Mining Machinery, Lindsay Auston
visited a mine in West Virginia. It was the first time Auston saw a single KH power
supply unit powering an RS20 Control System.
"We were impressed by its power and reliability," Auston said.
Auston left Joy three years ago, recently forming NSW-based Longwall Advantage to
provide an alternative source for longwall control system services. The company has
the agency for KH Controls.
Between 45 and 50 of the roughly 60 longwall systems in the United States have
controls systems powered by KH Controls power supplies. In addition, the longwall
lighting system introduced by KH in 1997 will be in service on 15 US longwalls by
the end of the year. Auston said Longwall Advantage was also reviewing whether to
introduce the lighting system into Australia.
Auston said he first saw an opportunity to introduce the KH Controls systems into
Australia when the safety related aspects of IS power supplies were first brought into
doubt some two years ago. Auston contacted Roger and Kevin Huczko of KH
Controls in the United States to review the design acceptability to Australian
Standards. An application for a Certificate of Conformity was submitted in March
1999 to SIMTARS.
"After 18 months of exhaustive testing we now have a certificate of conformity that
allows the coal industry access to the highest rated capacity IS supply in Australia
today," Auston said.
Testing of the power supplies is due to begin at a Bowen Basin mine in late October.
Compatibility compliance testing with the power supplies has been completed by Joy
and is due for completion with DBT.
The company said the certificate confirms an Ex (ia) I IP55 power supply conforming
to AS 2380.1 and AS 2380.7 with the following parameters:
Um = 125 VAC
The power supplies are available in a range from 10V, 750mA to 13.4V3.2A under
the same Certificate of Conformity and can be custom designed for specific
application such as AFC CST drives or gas monitoring systems. The power supplies
are available as stand alone electronic assemblies or as a complete assembly
including Ex d I flameproof enclosure.
"The model ISS1 power supply provides battery-like power quality while complying
with the strictest of international standards for intrinsic safety," Auston said.
The original version of the power supply expanded into a family of various ratings
and certifications for specific customer needs. The USA MSHA version is available in
output ratings up to 13.0 volts and 8.1 amperes. The EN version is available in output
ratings up to 13.4 volts and 3.2 amperes. The recently certified Australian Standard
version is available in output ratings up to 13.4 volts and 3.2 amperes.
KH Controls is a leading supplier of intrinsically safe power and lighting systems for
the US underground coal mining industry. Products include a family of intrinsically
safe power supplies, lighting systems, integrated systems and custom electronic
solutions. Power supplies are available in USA MSHA, European Norm and
Australian Standard versions.