In the high voltage power supply lines of Australia, Isolated Phase Bus (IPB) ducting systems are used to supply electrical energy from generators to transformers in power plants and large industrial plants. These systems are used for high current applications where performance, safety and fault containment are paramount.
At Aliweld Power, we specialise in supplying, modifying and installing of IPB systems across Australia. Over the last 25 years, we have been involved in aluminium welding, high voltage fabrication and site-based installation and have been involved in some of the biggest power projects in Australia for companies like Hitachi, Siemens and ABB.
In this article, we are going to explain what IPB systems are, the advantages of using IPB systems, the stages of installation and why choosing an experienced provider like Aliweld Power is the right choice.
What Is Isolated Phase Bus Ducting (IPB)?
Isolated Phase Bus (IPB) systems are a type of electrical bus duct used to supply high voltage current, usually in the range of 11kV to 33kV and above, between generators and step up transformers. Each phase conductor is placed in a grounded metal tube, thus separating the phases from each other and from ground.
Unlike the non-segregated or segregated bus systems where the phases may be housed together, IPB systems are totally phase isolated and therefore, the risk of phase to phase faults, short circuits and inductive heating is minimised.
A typical IPB system includes:
- Aluminium or copper bus conductors
- Individual grounded enclosures
- Insulators and spacers
- Expansion joints
- Air or gas insulation (depending on design)
- Elbows and flexible joints
- Terminations to GCBs and transformers
Why Use IPB Systems in Power Stations?
Power stations use very high current systems. The bus ducting must be able to carry big fault currents, high ambient temperatures, and mechanical stress and vibration.
Some of the important benefits of IPB systems include:
Enhanced Electrical Safety: The phase isolation minimises the risk of arcing or phase faults.
Less Magnetic Forces: With isolated enclosures and accurate conductor placement, the magnetic forces between phases are substantially reduced.
Better Cooling and Heat Dissipation: With one conductor per enclosure, IPB systems are more straightforward to ventilate or cool and hence, the temperature rise under load is lower.
Less Maintenance: IPB systems tend to have fewer internal problems than bundled bus systems since there is less chance of contamination and phase contact.
Fault Containment: The metal enclosures confine arc energy and stop the spread of fire or blast damage.
Because of these advantages, IPB systems are the norm for thermal power stations, hydro plants, synchronous condensers, and large scale renewable energy substations.
The Role of Aliweld Power in IPB Projects
At Aliweld Power, we do not just supply IPB ducting-we provide a total solution that includes:
- Supply of bus ducting components
- Custom fabrication and welding
- Modification of existing IPB systems
- Onsite installation and supervision
- Third-party NDT weld testing
- As-built drawings and QA documentation
Our team of AS1665-certified aluminium welders and project technicians are skilled in working in live substations and tight project schedules. We are often called upon to carry out emergency repairs, GCB replacements or retrofits on ageing IPB infrastructure.
The IPB Installation Process: Step by Step
Site Assessment and Planning
The first step in any IPB installation is a detailed site visit and engineering assessment. Our team evaluates:
- The layout between generator and transformer
- The location of the GCB
- Earthing and bonding requirements
- Access for installation equipment
- Clearance and alignment issues
This is the point at which your design and fabrication drawings are finalised. Our in-house drafting team can assist with revisions or create new schematics for modified systems. All IPB components—straight runs, elbows, expansion joints, supports, and terminations—are sourced or fabricated in our 2000 sqm Narangba facility. We use high-quality alloy materials for all aluminium conductors and enclosures, with options for custom thicknesses and radii.
Our workshop is equipped with:
- CNC machining
- Waterjet and laser cutting
- Alloy welding bays
- Galvanising logistics for steel components
Because we fabricate locally, we can offer shorter lead times than offshore providers and accommodate late design changes without compromising deadlines.
Onsite Installation
Aliweld Power’s mobile crews arrive onsite fully equipped with welding gear, generators, EWP licenses, rigging tools, and safety gear. Our team holds certifications in:
- Working at heights
- Confined space
- Dogging and rigging
- Telehandler operation
- HV site inductions
We install all components in accordance with the drawings and verify alignment and clearance before welding begins. All welds are completed to Australian Standards, with optional third-party NATA-approved NDT testing for full QA compliance.
System Integration and Termination
Once the main duct runs are installed, we connect the IPB to the GCB, transformer terminals, and earth systems. Special attention is paid to:
- Thermal expansion allowances
- Insulation clearances
- Grounding and bonding
- Stress relief at terminations
Our team ensures that every connection is safe, tested, and built to handle maximum load conditions.
Testing, Commissioning, and Handover
Post-installation, the system is subjected to:
- Electrical continuity testing
- Insulation resistance testing
- Weld inspection and documentation
- Visual and mechanical alignment checks
We provide as-built drawings, weld traceability reports, and documentation as part of the project closeout. If requested, we also participate in commissioning with your project engineers.
Why Choose Aliweld Power for Your IPB Installation?
When it comes to IPB installation in Australia, Aliweld Power stands out for:
Experience– We’ve been involved in dozens of high-profile GCB replacements, new power station builds and retrofit projects across the country. Our clients include global OEMs, Australian utilities, and major infrastructure contractors.
In-House Welding and Fabrication– No outsourcing. No delay. Our AS1665-certified welding team works under strict supervision and with full QA systems in place.
Mobile and Agile– We’re fully equipped for remote and urban work. Whether in the middle of the outback or on a tight metro site, we can deliver.
Full Compliance and Safety– Our Integrated Management System is certified to ISO 9001 (Quality), ISO 45001 (WHS), and ISO 14001 (Environmental). Every member of our workforce is trained and inducted to operate safely in high-voltage environments.
Isolated Phase Bus ducting is one of the most critical yet specialised components in any power generation facility. Faults, poor installation, or incorrect welding can lead to expensive downtime and even catastrophic failure.
With decades of experience, in-house fabrication, and certified welders, Aliweld Power provides a complete IPB solution—from supply and fabrication to installation and QA sign-off. Whether you’re upgrading an aging substation or building a new plant, we bring the tools, the people, and the precision to get the job done right.
Need IPB ducting or installation support? Contact Aliweld Power today for a consultation or quote.