Objectives

The primary objective of this tender is to appoint a qualified contractor to perform maintenance services on a 10 MVA 66/22 kV transformer at Levubu Substation. The aim is to ensure the reliable operation and longevity of the transformer through comprehensive maintenance activities, including inspections, testing, repairs, and servicing.

Scope

The scope of work includes:

• Visual inspection and servicing of the transformer
• Cleaning of bushings
• Silica gel replacement
• Earthing inspection
• Oil testing (DGA, BDV, Moisture)
• Oil filtration (per 1000L)
• Oil topping up
• Infrared (IR) & Polarization Index (PI) testing
• Transformer Turns Ratio (TTR) testing
• Winding resistance measurement
• Magnetic balance testing
• Protection relay functional checks and testing
• Relay replacement where necessary
• Trip circuit testing
• Thermography inspection
• On Load Tap Changer (OLTC) servicing and oil replacement
• Oil leak repairs and gasket/seal replacements

The contractor will be responsible for all activities necessary to maintain the transformer in optimal working condition, including compliance with technical standards and safety regulations.

Technical Requirements

The technical requirements include:

• Adherence to the scope of work as detailed in the tender document
• Provision of qualified and experienced personnel with relevant certifications (e.g., electrical engineering qualifications, specific personnel knowledge in transformer maintenance)
• Availability of necessary plant and equipment, such as cranes, trucks, and testing instruments, with proof of ownership or valid rental agreements
• Compliance with safety standards and proper documentation of all maintenance activities
• Completion of all testing and inspection activities as specified, with proper reporting and certification
• Provision of warranties for work performed and parts replaced
• Submission of detailed cost breakdowns and pricing schedules

Skills and Skills Requirements

The tender requires bidders to demonstrate the following skills and qualifications:

• Experience in Transformer Maintenance: Proven track record of successfully completing similar transformer maintenance projects, with references and completion certificates.
• Technical Expertise: Qualified electrical engineers with at least 5 years of experience in transformer repair and maintenance, including specific knowledge of 66/22 kV transformers.
• Personnel Qualifications: Skilled technicians with relevant certifications such as ORVHS (Level 1-4) for working on 22 kV networks, and wireman’s licenses for electricians.
• Project Management: Ability to effectively manage maintenance activities, coordinate testing, and ensure compliance with safety and technical standards.
• Plant and Equipment: Ownership or access to necessary plant, machinery, and testing equipment, with proof of certification and recent testing.
• Documentation and Reporting: Capacity to produce detailed reports, test certificates, and maintenance logs in accordance with technical standards.