11/06/2026
Walter Sisulu Local Municipality Successfully Advances Maletswai 20 MVA Substation Upgrade. A Strategic Investment in Electrical Infrastructure Renewal and Network Reliability:
By Louw Brand and Deon Roodt
DFR Engineers Eastern Cape
The Walter Sisulu Local Municipality (WSLM) continues to demonstrate its commitment to strengthening municipal electrical infrastructure through the successful implementation of the Maletswai 20 MVA Substation Upgrade Project in Aliwal North, Eastern Cape.
The project represents a significant investment in network resilience and supply reliability and forms part of the Municipality's ongoing strategy to modernise ageing infrastructure while providing sufficient capacity for future growth and economic development.
The works include the replacement and commissioning of a new 20 MVA power transformer, installation of associated protection and control systems, refurbishment of substation infrastructure and implementation of various security and operational improvements.
Project Overview:
Client: Walter Sisulu Local Municipality
Consulting Engineers: DFR Engineers Eastern Cape
Contractor: SNR Electrical CC
Contract Value: Approximately R14.55 million (Incl. VAT)
Voltage Level: 22/11 kV Distribution System
Transformer Capacity: 20 MVA
Scope of Works
The project comprised:
• Installation of a new 20 MVA power transformer
• Refurbishment of transformer plinth and civil infrastructure
• Installation of a Neutral Earthing Resistor (NER)
• High-voltage equipment upgrades
• Transformer protection and control systems
• New marshalling kiosk
• Perimeter security enhancements
• Floodlighting installations
• Cable reticulation and auxiliary services
• Commissioning and operational integration
New 20 MVA Transformer Installation
Newly Installed 20 MVA Transformer at Maletswai Substation.
The centrepiece of the project is the installation of a modern 20 MVA oil-filled power transformer designed to improve network stability and provide long-term operational reliability.
The transformer incorporates modern monitoring and protection systems together with on-load tap changing capabilities to ensure voltage regulation and improved operational flexibility under varying load conditions.
The transformer was subjected to detailed factory acceptance inspections prior to delivery to site and underwent rigorous quality assurance verification before installation.
Advanced Monitoring and Protection Systems
Transformer Monitoring and Tap Changer Instrumentation.
The transformer incorporates dedicated monitoring systems for:
• Main tank oil level monitoring
• On-load tap changer oil level monitoring
• Pressure relief protection
• Buchholz and gas relay interfaces
• Transformer condition monitoring
The monitoring arrangements provide operational personnel with valuable information regarding transformer health and allow preventative maintenance interventions to be undertaken before faults develop into failures.
The installation has also been designed to facilitate future SCADA and remote monitoring integration.
Engineering Excellence Through Collaboration
Project Team During Site Inspection and Verification
Successful implementation of a project of this nature requires close collaboration between municipal officials, consulting engineers, contractors, manufacturers and commissioning specialists.
Throughout the project, regular progress inspections, factory acceptance testing, technical reviews and stakeholder engagements ensured that quality standards were maintained and that the installation complied with applicable municipal and industry requirements.
Particular emphasis was placed on safety, quality assurance and operational readiness throughout the construction phase.
Infrastructure for Future Growth
Completed Transformer Installation Prior to Final Commissioning.
Upon completion and commissioning, the upgraded facility will provide:
• Improved electricity supply reliability
• Increased operational flexibility
• Enhanced voltage regulation capability
• Reduced maintenance risk
• Improved network resilience
• Capacity for future load growth
The project also contributes to improved service delivery and provides a foundation for future infrastructure development within the Municipality's area of supply.
Looking Forward
Municipal electrical infrastructure across South Africa continues to face increasing pressure due to ageing assets, growing demand and constrained maintenance budgets. The Maletswai 20 MVA Substation Upgrade demonstrates how targeted infrastructure investment can significantly improve reliability and operational performance while extending asset life.
Walter Sisulu Local Municipality is commended for its proactive approach to infrastructure renewal and for investing in critical assets that will continue serving the community for decades to come.
Project Team:
Client: Walter Sisulu Local Municipality
Consulting Engineers: DFR Engineers Eastern Cape
Project Lead: Louw Brand
Director: Deon Roodt
Contractor: SNR Electrical CC
Project Value: R14.55 Million
Commissioning Date: 2025/2026
