This project, under NRC (Northern Refinery Company) contracts, involves the rehabilitation of ten (10)
medium-voltage substations, as well as one main substation rated from 33 kV to 11 kV, stepping down
further to 3.3 kV and 0.4 kV. The remaining stations are 3.3 kV to 0.4 kV. Our key focus is to supply and
install new switchgear and transformers that comply with the refinery’s technical specifications while
ensuring minimal operational interruptions at Baiji Refinery.

Major Scope of Work:
✓ Main Substation (33 kV → 11 kV → 3.3 kV → 0.4 kV):
• Installation of new GIS switchgear from Siemens Germany, ensuring modern and reliable operation.
• Coordination with existing civil structures to accommodate the dimensions and mounting requirements of
the GIS switchgear.

✓ Other Substations (3.3 kV → 0.4 kV):
• Retrofit or replacement of switchgear with Sivacon S8 units from Siemens Leipzig, Germany.
• Verification and re-design of cable routes and cross-sections as needed to match new equipment ratings.

✓ Transformers :
• Compliance with specifications requiring European-manufactured transformers.
• Shift from Siemens Austria (which no longer produces mineral-oil-based transformers) to Machi Power (Italy)
to meet the refinery’s mineral-oil requirements.

✓ Integration of Old and New Schematics:
• Comprehensive review of existing (legacy) control and protection drawings to ensure seamless integration
with new switchgear layouts.
• Adaptation of old wiring diagrams to new control schemes, including power and control interfaces for
medium- and low-voltage pumps and motors.

✓ Civil and Structural Work:
• Drilling and fitting modifications in existing substation buildings to properly install new GIS equipment.
• Ensuring correct alignment and safe clearance for all switchgear and auxiliary systems.

✓ Operational Coordination with Baiji Refinery:
• Development of an installation and commissioning schedule that aligns with ongoing refinery operations.
• Minimizing downtime by phasing installations so only specific refinery units are taken offline during critical
work.

Key Challenges:

✓ Matching New Equipment to Existing Civil Works
Fitting GIS switchgear into the original substation footprint requires precise civil modifications and accurate
dimension checks.

✓ Ensuring Compatibility with Legacy Schematics
Old control and protection drawings must be updated and aligned with the new designs, which involves
extensive engineering reviews.

✓ Transformer Supply Constraints
Sourcing transformers that meet mineral-oil specifications from European manufacturers posed scheduling
and supply-chain challenges.

✓ Operational Continuity
Coordinating installation phases so the refinery can maintain critical operations throughout the upgrade
process.

✓ Cable Sizing and Routing
The re-evaluation of cable cross-sections and conduit pathways is critical to accommodate new switchgear
rating requirements and improve system reliability.