A partnership agreement has been signed between MV Switchgear and a US switchgear manufacturer in which the local division undertakes to manufacture vacuum interrupters (VI’s) for a new product being launched into the US market.
“The company, which specialises in the manufacture of high voltage switchgear and automation products for transmission and distribution systems, is developing a novel switchgear product range incorporating vacuum interrupter technology. It approached us due to our well-established reputation as a manufacturer of high quality VI’s – an additional attraction for them in partnering with us being that we don’t supply VI’s to any of their competitors or suppliers,” Rhett Kelly, MV Switchgear’s Design & Development Manager, explained.
MV Switchgear’s Vacuum Interrupters South Africa (VISA) plant, the only VI manufacturing facility in the Southern Hemisphere, has been in operation for over 30 years. The partnership agreement with the US company marks the first time the plant is to embark on large-scale manufacturing of VI’s for another switchgear manufacturer, as to date it has manufactured VI’s primarily for its own products.
In terms of the agreement, signed in May 2020, MV Switchgear undertook to build prototype VI’s and various VI parts in accordance with the US company’s designs as part of the technology development process and thereafter will manufacture the VI’s for full-scale production.
“Production commenced this year with capacity for up to 20 000 VI’s per year. The agreement also makes provision for us to make VI parts as well as manufacture and assemble the VI’s. So far, we’ve proven to the US company our ability to make the parts that are required,” Rhett pointed out.
The VI’s are of a different design configuration than those MV Switchgear currently produces. The differences include greater compactness, the new VI’s being about an eighth of the size of the existing product, while having a much higher voltage rating of 27kV, as against 12kV, unique vapour and bellows shield designs, stringent tolerances and utilising specialised non-conventional materials.
“We have had to expand our quality management system and controls in order to meet the US company’s stringent requirements,” said Rhett.
In order to meet the increased volumes required, the US company has invested a substantial amount of money for ACTOM to upgrade the existing VISA plant.
Part of this amount has gone towards refurbishing and upgrading an existing second braze furnace that has been out of service for several years, as just one operating braze furnace has been sufficient until now to serve MV Switchgear’s internal production requirements.
The other part of the investment is to establish a semi-automated VI test facility in the plant to manage the testing of the increased volumes of units due to be produced.
The custom-designed testing programme includes power frequency voltage withstand testing, high voltage conditioning of the contacts, power frequency arc conditioning, resistance measurement, pressure measurement using a magnetron, and X-ray emission testing.
The braze furnace refurbishment was completed at the beginning of last year, while installation and commissioning of the semi-automated test facility was completed in August this year.
