MV Switchgear Divisional News – MV Gas-Insulated Ring Main Unit

MV Gas-Insulated Ring Main Unit


“We selected the compact non-extensible FBX-C CCT2 model to adapt for local use to start with because the biggest market for ring main units in South Africa is in miniature substation applications. This model is perfectly suited to this application as it consists of two load-break, fault-make isolators with a circuit breaker T-off to the transformer, which is the market preference,” explained Greg Whyte, ACTOM Switchgear’s marketing and customer services strategy manager.

The company worked in close partnership with Areva T&D, its Europe-based technology partner, in developing additional features for the South African version of the FBX-C CCT2 so that it meets local requirements and conform to the local standards – the applicable standards being NRS 006 and SANS 1874.

The additional special features that distinguish the local version from the standard European equivalent are:

· An integral cable test facility that allows the test connections to be applied before removal of the earthing star point.

· An easily accessible self-powered protection relay.

· Adequate phase-to-phase clearances within the cable compartments suitable for 12 kV applications where unscreened cable terminations are typically used on paper- and XLPE-insulated cable.

· Cable support for 3-core cable.

Areva T&D’s FBX range of ring main units, available in voltages of up to 24 kV, are supplied in extensible or non-extensible configuration according to customer requirements, the extensible version being equipped with a set of bushings on the end of the busbar to allow extra functions to be added to the board later.

How customers should choose between ACTOM Switchgear’s well-proven in-house designed and manufactured “K” range of oil-insulated switchgear and the FBX gas-insulated unit depends firstly on their willingness to pay a premium for the new equipment, Whyte pointed out.

“However, what you have to bear in mind is that although the FBX’s up-front cost is higher, it requires significantly less maintenance than the oil-insulated unit and therefore should be compared on a life cycle costing basis. In addition, from a safety point of view it can be internal arc classified in terms of IEC 62271, therefore giving assurance of its ability to perform safely under internal arc conditions, for example, in the event of a cable termination failure.”

He added that FBX is especially well suited to automation of secondary distribution networks, due to its modular design and various options available that include motorised switching devices and remote control modules.

Primary distribution systems product PIX also on offer

ACTOM Switchgear has also recently introduced a primary distribution systems medium voltage product from Areva T&D called PIX.

PIX is an advanced air-insulated range of switchgear, already well-proven abroad, that is ideally suited to power generation applications, which Astom Switchgear is hoping will win acceptance for application in the MV networks at Eskom’s new Medupi coal-fired power station currently under construction near Lephalale, Limpopo Province – as with the various other new power plants due to be established over the next several years to meet current and future requirements in Southern Africa.

“The PIX or PIX-H range is, we believe, the product of choice in instances where rating up to 50 kA and 4000 A are required,” Whyte commented. The PIX range has been tested for internal arc classification up to 50 kA for 17,5 kV.

As with FBX, PIX has an upper voltage rating of 24 kV and like that secondary distribution systems product is compact, requires minimum maintenance and has a number of built-in safety features.

ACTOM Switchgear is part of the South African black empowered group ACTOM (Pty) Ltd. The current rating in terms of the Broad Based Black Economic Empowerment Act of 2003 and the Department of Trade and Industry’s Codes of Good Practice is Level 5, local value adding supplier.

Black empowerment investors include Tiso (9.5%), Kagiso (9.5%), individuals, management and employees (9%).

ACTOM South Africa employs in excess of 6 000 people and has an annual order intake in excess of R5bn. It has 27 operating units, 22 production facilities and 25 distribution centres throughout South Africa.

ACTOM South Africa co-operates with Alstom France as a preferred partner for environmental equipment and in serving the maintenance, upgrade and retrofit market for larger boilers, as well as for railway transport activities.

It has exclusive distribution, technology and representation rights for Areva T&D in Southern Africa and maintains management, technical and commercial links to Areva T&D business units in Europe.

For further information contact Greg Whyte, ACTOM Switchgear

PO Box 13024, Knights 1413

Tel (011) 820-5140 Fax (011) 820-5212