A manager of a large gold mine once told me after I commented on the two hour drive to the mine off the main road, that they don’t build mines in the middle of cities. I had never thought about that before but reflecting on his comment and applying it to my experience selling to mines, I found it to be very true. Mines are built in some of the most remote parts of the world, mainly due to the open space required to pull precious and industrial metals out of the earth. The remote nature of mines means that utility power is often unavailable at the site, requiring the use of several megawatts of generator power to power the mine operations and man camps where the miners live.
The Requirements and the Concept
Recently, Power Assemblies was approached by a Caterpillar generator dealer in Alaska to build a mobile substation to feed one of these mine sites in a remote area of the state. The substation needed to be constructed in a self-contained metal box called a Conex so it could be moved around the site depending on the power needs of the mine. Mounting a substation in a Conex is not a new concept, however making the Conex mobile with easily accessible power connections was a fairly custom undertaking.
The design engineers of Power Assemblies decided the best way to make the Conex mobile would be to mount it on a custom trailer which could be towed by a truck or large shovel, which are prevalent on mine sites. Inside the Conex was a primary 15KV fusible switch, dry-type pad mount transformer, and a 480V secondary distribution switchboard. The incoming connections to the switch were made through the bottom of the Conex by providing a large cut out in the bottom of the trailer leading to the switch. The connection to the distribution switchboard was made by mounting several rows of camlocks on the outside of the Conex to allow the generator cable assemblies to connect to it.
The completed mobile substation was shipped to the Caterpillar dealer within 8 weeks after receipt of order. It was on site shortly thereafter and has been distributing power various parts of the site ever since.