Objectives

The primary objective of this tender is to appoint a qualified and experienced contractor to perform maintenance of power transformers at various substations over a period of 3 years. The contractor is expected to conduct condition assessments, prepare maintenance reports, and carry out preventative and corrective maintenance activities to ensure optimal transformer performance and reliability.

Scope

The scope encompasses maintenance services for all intake, primary, and secondary substations as applicable. Responsibilities include supplying, delivering, installing equipment and materials, conducting electrical tests, oil analysis, and performing onsite/offsite repairs. Specific activities include oil drainage, dehydration breather servicing, fan and pump maintenance, conservator and Buchholz inspections, temperature indicator testing, moisture removal, and gas monitoring. The contractor must respond to requests from the municipality as and when required for a duration of 3 years.

Technical Requirements

• Provision of all necessary equipment, tools, and materials for maintenance activities.
• Compliance with IEC/SANS standards for electrical testing, including no-load tests, impedance, partial discharge, capacitance, SFRA, oil quality tests, and gas analysis.
• Responsibility for conducting condition assessments, preparing reports, and executing preventative and corrective maintenance.
• Supply and installation of field test facilities and equipment, ensuring all tests are conducted with fully assembled transformers and test certificates issued.
• Responsibility for onsite activities such as oil top-up, dehydration breather servicing, fan and pump maintenance, conservator and Buchholz inspections, and calibration of gas monitoring units.
• Adherence to safety standards and standards of the municipality, including IEC/SANS standards.
• Provision of quality control and defect rectification during electrical testing and inspections.

Skills and Skills Requirements

• Qualified electrical engineers with NQF Level 6 or higher in Electrical Engineering.
• Experience of at least 7 years in power transformer maintenance, including condition assessments and repairs.
• Certified HV Regs qualification and rigging/trade test certificates, SAQA accredited for foreign nationals.
• Proven experience with transformer testing, oil analysis, and online gas monitoring systems.
• Capability to supply, deliver, and install all required equipment and materials, including plant and tools with calibration certificates.
• Competence in electrical testing, including SFRA, DGA, capacitance, partial discharge, impedance, and oil quality testing.
• Skilled personnel for onsite inspection, testing, and maintenance activities, including safety officers and technical supervisors.
• Ability to respond promptly to municipality requests and execute maintenance activities efficiently and safely.