British equipment starts Russian mining

. Made by Baldwin and Francis in Sheffield, using an OEM kit of parts supplied by Soft Start in Great Yarmouth, it will simultaneously start three separate motors, each rated at 400kW, and run the mine’s main gate conveyor which carries coal from the working face to the mine shaft. The kit consisted of thyristors power modules, a fibre optic Electronic Potential Transformer for firing the thyristors, electronic control modules and a user interface. Baldwin and Francis took the components and built them onto a chassis which was then enclosed in an Ex D housing. Because of space limitations, the thyristors had to be supplied with specially made, right-angled couplings instead of conventional in-line ones. The fibre optics were necessary to electrically isolate the high and low voltage sections of the soft starts and eliminate the possibility of flashovers. Mark Ramsden of Baldwin & Francis explained, “The worldwide mining industry is still fairly new to electronic solutions to do with starting motors underground and we are doing a lot of pioneering work in this respect. Electronics tend not to like the heat and gases typically found underground, and the thought that they may cause a spark is an anathema to mining engineers the world over. It is our job to show that electronics is robust enough and starter sparking isn’t a problem.”