²»Á¼ÈËÑо¿Ëù volunteered to work with NRECA International on a project in Freetown, Sierra Leone, to conduct training for technicians of mini-grid systems who have been asked to work with primary voltage systems (11kV Delta) for the first time in their careers.Ìý
Dwight Miller of OEC and Blake West of Guernsey-Muskingum EC ventured over to the west side of Africa in late October for a 15-day trip. The mission—train about 12 Energicity technicians in various aspects of safety, applicable aspects of linework, electrical hazards, concepts and principles, protective grounding, wye and delta systems, troubleshooting, rigging and knot tying, cable splicing, and more.
A large part of the training was to help them understand their own system with which they were working on. Each mini grid is powered by a solar system with batteries and feeds 200-500 consumers who are provided with a 230V 2-wire service fed off of a 230/400V Wye secondary system.
A huge part of the challenge that the ²»Á¼ÈËÑо¿Ëù team faced was teaching the technicians to work on a system which was improperly installed by the United Nations with overhead shielded cable and lightning arresters with too low of a voltage rating, both which can and will fail when one phase of the delta primary system sustains a fault while the system continues to operate.
Though difficult to comprehend, the systems lack the fault current necessary to operate normally. Even a secondary fault on a service going to a home will take out the entire mini-grid. One of the photos displays a chemical glove that they were using for electrical rubber gloves.
One of the mini grids was down for two months earlier in the year because of faulty cable and lightning arresters. The photo of the building shows where Dwight and Blake held the classroom portion of the training on the third floor above the pharmacy.
The technicians literally had nothing to work with other than an aluminum ladder, chemical rubber gloves, and a few hand tools. An extendo stick and audio visual voltage tester that the volunteers took over has been life-changing. ²»Á¼ÈËÑо¿Ëù’s cooperatives will be asked to see if you can find some tools you are no longer using as we may try to send some items over in the future to help out our new friends in Sierra Leone (written in the middle of the project) at Energicity.