Electrical Power & Protection

Onsite oil treatment saves transformers

June 2018 Electrical Power & Protection

With what is claimed to be the largest mobile oil regeneration plant in Africa, WEG Transformers Africa (WTA) plays a vital role in extending the life of South Africa’s transformer population and preventing unplanned downtime within electricity transmission systems. According to engineering manager, Ronaldo Bertoldi, ageing transformer oil introduces a number of risks into the performance and longevity of oil cooled transformers. “Moisture and impurities reduce the intended insulating effect that oil has within the windings and produces acid, making it more likely for breakdowns to occur, with potentially severe damage to the transformer itself,” he says.

WTA is able to conduct an oil regeneration service onsite for large transformers. This is done by transporting the regeneration plant by road and setting it up at the location required by the customer. Once linked up to the transformer, the unit circulates the oil through a process which involves filtering it through Fuller’s earth to remove impurities.

Careful sampling of the oil is first conducted in accordance with ISO and SANS sampling procedures by the company’s field teams, so that oil testing can establish the severity of the contamination. Laboratory tests, also conducted by WTA, are able to pick up the extent of cellulose breakdown from the insulation around the windings, oil decomposition and any moisture ingress. “The regeneration process removes acids, as well as absorbing moisture and oil decaying products through a hot oil circulation process through Fullers earth and inline oil purification in a closed loop path,” Bertoldi explains.

The process of purification only is shorter and uses inline micro filters to remove water, alcohol, dissolved gases, oxides and solid impurities. This is also a hot oil circulation process conducted in a closed loop path, and can usually be conducted in less than a day, depending on the condition of the oil. The number of passes that the oil requires through the system is based on the laboratory tests that indicate the level of contamination. Most of this work is conducted for end-users of transformers in various industrial sectors, with municipalities currently doing less oil purification or regeneration than in the past.

For more information contact Zest WEG Group Africa, + 27 (0)11 723 6000, info@zestweg.com, www.zestweg.com


Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Energy data acquisition made easy
August 2021, Phoenix Contact , Electrical Power & Protection
By developing the new components of the EMpro product family, Phoenix Contact has found a solution that satisfies most energy data gathering applications.

Power supply for machine applications
August 2021, Vepac Electronics , Electrical Power & Protection
With vacuum encapsulated technology, MTM Power’s focus is on encapsulated, robust, long-life, temperature-resistant and maintenance-free power supply modules.

Transformer for special applications
July 2021, ASSTech Process Electronics + Instrumentation , Electrical Power & Protection
The Jumo IPC 300 was developed for the control of heating loads that previously required an additional transformer for power control.

ABB launches new MCB range
July 2021, ABB South Africa , Electrical Power & Protection
The circuit breaker industry sees the local launch of a high-quality product as ABB Electrification introduces its new range of 3 kA SR200T miniature circuit breakers.

Hitachi ABB Power Grids powers SA to a greener future
August 2021 , Electrical Power & Protection
The move towards decentralised power grids and a large-scale adoption of renewable energy will significantly alter the energy market in South Africa.

The Pepperl+Fuchs M-LB-5000 surge protection system
June 2021, Pepperl+Fuchs , Electrical Power & Protection
Using the modular M-LB-5000 system with diagnostics eliminates extensive testing and operational interruptions. It is supplemented by the M-LB-2000 system for applications in which a minimum specification is sufficient.

Beckhoff expands power supply portfolio
June 2021, Beckhoff Automation , Electrical Power & Protection
Buffer and redundancy modules for 24/48 VDC power supply increase system availability.

Legrand’s new P17 Tempra Pro plugs
June 2021, Legrand , Electrical Power & Protection
New to Legrand’s range of plugs and sockets is the versatile P17 Tempra Pro range, which has been developed for safe installation in indoor and outdoor environments.

UPS series with One Cable Technology
April 2021, Beckhoff Automation , Electrical Power & Protection
Beckhoff’s new CU81xx UPS series is designed for universal use. Due above all to the flexible connection options extending up to One Cable Technology for uninterruptible power supply (UPS-OCT), the series ...

Flameproof switchgear for system protection
April 2021, Becker Mining South Africa , Electrical Power & Protection
Becker Mining South Africa’s Energy Distribution division manufactures customised switchgear, designed for the efficient distribution of electrical power.