Local designer, manufacturer and supplier of equipment, systems and services for medium voltage (MV) electricity distribution MV Switchgear, a division of electrical equipment supplier Actom, has been awarded a contract for GELPAG solid insulated switchgear (SIS) units for more underground substations at the extensive new Kamoa-Kakula copper mine, in the Democratic Republic of Congo (DRC).

The award follows as the company has executed two large contracts over the past two years involving the manufacture, supply and installation of numerous air-insulated switchgear (AIS) panels for 11 kV substations at the mine.

A total 233 of MV Switchgear’s well-known and widely used SBV4E brand of AIS switchgear panels were produced and supplied by the division to equip surface and underground substations at the new mine.

They comprised 140 panels for eight surface substations and 93 panels for five underground substations.

The latest contract for 149 GELPAG SIS units for eight underground substations, was awarded late last year for delivery in August 2023 and has resulted in having to address changes in underground conditions at the mine as mining operations progressed.

“Harsh environmental conditions such as high levels of humidity and dust were found to be present in these underground sections, necessitating the introduction of more specialised switchgear equipped to cope with these conditions,” said MW Switchgear design and development manager Rhett Kelly.

“In such a situation the choice is typically between fixed pattern gas-insulated switchgear and SIS. We were confident in recommending to DRA Global of South Africa, the engineering consultants for the Kamoa project, our GELPAG SIS product for this purpose,” Kelly noted.

With MV Switchgear experiencing growing demand for GELPAG since introducing it into the local market in late 2020, it recently arranged, in collaboration with its overseas-based original-equipment manufacturer (OEM) partner, to start local manufacture of some of the product’s ancillary components.

“By taking this step we’ve substantially shortened the production lead times, as we can now manufacture the agreed locally produced components in parallel with the OEM’s production of the main product, thereby speeding up both final assembly of the product in our plant as well as delivery to the end-user,” Kelly said.

The Kamoa-Kakula mine will be the first recipient of GELPAG panels in terms of the new arrangement.

The division’s technology development specialist, Johan Jordaan, meanwhile said that the components being manufactured locally, now and in the future, were the LV compartment, internal arc ducting and the drop-down boxes for the cable terminations.

“While not normally required for the GELPAG product range, custom drop-down boxes have been designed to accommodate the 3-core cable terminations with core balance current transformers specified by the customer,” he said.

“To further speed up and simplify production and delivery, we’ve developed an LV connector system which allows the panel’s circuit-breaker, disconnector and earth switch wiring to interface with the LV control wiring via a standard multi-pin plug-and-socket system,” he added.

MV Switchgear has also developed a wiring test rig to enable it to test and verify the wiring of each LV compartment before the GELPAG panels they are to be connected to arrive from abroad.