Objectives

The primary objective of this tender is to supply, install, and commission a 3kV DC 6MVA traction transformer at Hamelfontein Traction Substation, ensuring compliance with relevant standards, environmental regulations, and technical specifications. The project aims to deliver a reliable transformer that supports railway traction power needs while minimizing environmental impact and ensuring safety and quality standards are met.

Scope

The scope includes:

• Supply of a 3kV DC traction transformer rated at 6MVA.
• Installation and commissioning of the transformer at Hamelfontein substation.
• Provision of associated components such as current transformers, lightning arrestors, bushings, radiators, fittings, and control devices.
• Ensuring the transformer design complies with specified technical, environmental, and safety standards.
• Testing, inspection, and handover to Transnet.

Technical Requirements

The technical specifications include:

• Transformer shall be outdoor, oil natural air natural (ONAN) cooled, and comply with SANS 60076-1.
• Primary winding star-connected; secondary winding configured for 6 or 12 pulse rectification, with phase shift options (+15°, -15°) or delta and star windings.
• Secondary voltage approximately 1220V to 1440V, with provisions for a tertiary winding rated at 50kVA, 400V three-phase.
• Temperature rise not exceeding 65°C under continuous full load conditions.
• Voltage regulation within 5% across tap positions (+/- 2.5% and +/- 5%).
• Impedance not less than 8%, optimized for minimal voltage regulation.
• Built-in current transformers compliant with IEC standards.
• Insulation levels and dielectric tests in accordance with SANS standards.
• Robust mechanical construction to withstand fault and mechanical stresses.
• Fittings including bushings, radiators, conservator, pressure relief devices, and monitoring instruments (thermometer, Buchholz relay, etc.).
• Corrosion protection, painting, and galvanization suitable for coastal/heavy polluted environments.
• Transformer oil shall be unused mineral oil meeting SANS 555 specifications.
• Testing, type approval, and routine inspections in line with IEC and SANS standards.
• Compliance with environmental and safety standards, including lightning, surge, and overvoltage protection.

Skills Requirements

The tenderer must demonstrate:

• Expertise in designing and manufacturing power transformers, specifically traction transformers for railway applications.
• Proficiency in complying with international (IEC), national (SANS), and Transnet standards.
• Capability to produce detailed technical documentation, including drawings, data sheets, and test certificates.
• Experience in outdoor transformer installation, including handling of mechanical and electrical components in challenging environments.
• Knowledge of environmental management, corrosion protection, and painting suitable for coastal/heavy pollution zones.
• Ability to conduct comprehensive testing, inspections, and quality assurance procedures.
• Qualified personnel for installation, commissioning, and handover, including electrical engineers, technicians, and environmental specialists.
• Capability to develop and implement safety, health, and environmental management plans.
• Experience in project management, including coordination with Transnet representatives and adherence to technical and environmental specifications.

Summary

This tender requires a technically competent and environmentally compliant supplier capable of delivering a high-quality traction transformer, ensuring safety, reliability, and minimal environmental impact throughout the project lifecycle.