Who we are
Southern Transformers is an Australian manufacturer specialising in low-voltage dry-type transformers for industrial and commercial applications.
From our Melbourne-based factory, we design, build and fully test 3-phase isolation transformers, auto-transformers, custom LV/MV solutions up to 3.3 kV, and specialised solutions for mining, renewables, data centres, rail, defence and infrastructure.
Everything we do is driven by reliability, craftsmanship and technical excellence. With fully in-house manufacturing and testing, premium materials and rigorous AS/NZS/IEC compliance, we deliver transformers that customers trust to run critical equipment safely, day after day, year after year.
Our Mission
To empower people to support and sustain the industries that shape our world.
Our Purpose
To continue driving industry and people forward.
Where we Started
1972
Where we Started
From Garage to Factory
Noel and Millicent Voller started Southern Transformers in the late 1960s. Noel was working for Phillips (Astor Radio) back then, in high-volume production of transformers. Noel noticed that the company was consistently having to turn away customers wanting one-off or small-batch custom transformers.
Seeing a niche in the market, and with Phillips’ permission, Noel commenced designing and winding project-specific, custom transformers in their garage. It quickly took off. Noel left Phillips and set up shop in a factory on Japaddy Street, Mordialloc, in 1972.
Scott Renwick became Production Manager
Scott Renwick, Noel’s nephew, started working at the factory in 1974, winding transformers during university holidays. He became Production Manager in 1976 and, with his parents, John (Peter) and Margaret Renwick, went on to purchase the business from Noel. He successfully grew it for the following 40+ years.
What began as a small specialist workshop quickly grew into a trusted supplier of transformers, chokes, and other wound componentry for not just Australia, but for over 85 countries.
The business was, and still is, known for problem-solving, high-end craftsmanship, and the willingness to take on complex custom work. Its core values have always been around people; ensuring safe and satisfied customers, suppliers, and employees. Southern Transformers has always been a family.
1974
2000
Southern Transformers become a trusted supplier in new markets
Until the early 2000s, Southern Transformers focused on supplying wound componentry (transformers, chokes, coils, etc) to markets such as local manufacturing (OEMs), rail, and defence industries.
It was a time when Australia was an innovative world-leading force within the electrical manufacturing industry. During this time, Southern Transformers earned a reputation for reliability across manufacturing, industrial automation, and commercial electrical markets, becoming the quiet achiever behind countless Australian projects.
Then, as the world started to become smaller, access to offshore alternatives became prevalent, and Australian manufacturing and innovation were caught and, in many areas, surpassed.
It was time for Southern Transformers to look to the future and consider where they would continue to stand apart.
Scott decided to focus more on transformers over the other wound components we were also known for. He expanded the workshop, invested in new winding and assembly equipment, and focused on building a deep technical understanding.
He brought in transformer design maestro, Ken Sumsion, as well as Craig Phelan to head up the Technical and Testing departments. This injection of expertise enabled Southern Transformers to grow its capability to design, build, and test LV 3-phase isolation transformers, auto-transformers, and custom-engineered solutions.
This transition saw Southern Transformers become a trusted supplier in new markets, primarily mining and renewable industries, and unlocked a new, bigger future for Southern Transformers.
A New Chapter of Leadership and Growth at Southern Transformers
In 2021, Scott and his wife, Marie, sold the business to their son, James Renwick, and Craig. James, coming from a business and marketing background, and Craig, with his technical and system-based expertise, have been a perfect team, working hard to build on Scott’s successes.
They’ve worked to implement and refine processes, systems, and enter new markets, to continue to build Southern Transformers into the industry-leading manufacturer it is today. Slowly but surely, Southern Transformers’ manufacturing capability has grown, allowing them to build 3-phase isolation transformers up to 750kVA.
Scott is still involved in the business, acting as a design consultant, a role he relishes, as he can do this anywhere in the world. He also enjoys time on the tennis court, the golf course, the ski slope, or with his grandchildren.
2021
2024
Southern Transformers doubled its manufacturing footprint
In 2024 to 2025, Southern Transformers doubled its manufacturing footprint by securing a secondary factory, right next door, allowing increased production capacity, more efficient workflows, and additional high-end test infrastructure.
This growth ensured we could remain competitive on quality, price, and delivery timelines, while keeping all manufacturing right here in Australia.
Today
Today, Southern Transformers is recognised as one of Australia’s leading LV dry-type transformer manufacturers. We design purpose-built, solution-based transformers with power ratings up to 750kVA, and supply to critical industries, including:
- Mining and resources
- Renewable energy (SPS, BESS, solar/wind/hydro, off-grid systems)
- Data centres
- Rail and infrastructure
- Defence and government
- Industrial automation and commercial facilities
We continue to invest in our people, our equipment and our capabilities. We are committed to delivering transformers that stand the test of time and supporting the industries that keep Australia moving.
After almost 50 years from conception in Noel’s garage to a dual-facility manufacturing powerhouse, our core purpose remains the same: to empower people who support and sustain the industries that shape our world.
Meet our Team
James Renwick Director
Sales and BDM
Craig Phelan Director
Technical and Testing
Darren ‘Daz’ Hayes
Factory Manager
Scott Renwick
Technical Design
Ken Sumsion
Design Consultant
Katherine ‘Kat’ Bassett
Administration Coordinator
Stewart ‘Stewie’ Rennie
Head Winder
Jadwiga ‘Wiga’ Buloch
Winder (40+ years)
Callum Ryan
Winder and Assembly
Shannon Vernall
Assembly and Quality Assurance
Grigory ‘Greg’ Utrobin
Assembly
Dimuthu ‘Dima’ Fernando
Assembly
Honorary Mentions
Sue Kerr Previous
Administration for 25+ years
Stasia Zajac
Retired Winder for 35+ years
Bruce Towan
Previous Winder for 20+ years
Leadership
Craig Phelan
Director
Craig is a technical electrical specialist, cutting his teeth at CSIRO as an apprentice and entering the industry as an esteemed radio expert.
Craig worked for various companies, primarily M Power (now M & H Power), designing, building and testing highly involved and intricate custom solutions.
M & H were a customer of Southern Transformers for over 10 years, with Southern Transformers designing transformers to Craig’s designs. A mutually beneficial opportunity came up in 2012 for Craig to join Southern Transformers, where he became the Technical and Testing Officer and second-in-charge under Scott. Over the next 10 years, Craig would learn everything about the business, and in 2021, with James, he bought the business from Scott.
Craig continues to manage the technical and testing aspects of our production, developing GAs and schematics, testing transformers, and improving internal processes and systems for more efficient production.
Craig has a deep passion and understanding for all things electronic, with a strong appreciation and attention to safety, compliance and improvement, exactly who you want spearheading a transformer manufacturing company.
Craig’s happy place is in Thailand, with visions of having a small farm there in retirement for him, his wife and his sons to enjoy.
James Renwick
Director
Southern Transformers moved into the 8 Superior Drive facility in 1989, the same year James Scott’s son was born. Being so, James has been in and around the factory and business all his life, scooting around the factory floor on the pallet jack since he could walk (don’t tell WorkSafe!)
James was involved in production and fabrication throughout his school years, working holidays on the floor, winding, laminating, terminating, and performing general duties.
James completed his degree in Business with a double major in Marketing and Human Resources. From there, he worked as Business Development Manager for various small businesses, craft breweries and boutique travel agencies, before seizing the opportunity to buy into Southern Transformers alongside Craig, as Scott looked to step back from the business and enjoy more travel and sporting activities.
With his experience in small business operations and development, paired with his ingrained understanding of Southern Transformers as a business, he has helped continue to bring the reliability and support that Southern Transformers provides to the wider Australian and international market.
You’ll find James in his happy place snowboarding, tobogganing or building a snowman with his wife, Emily and three kids.
What Makes us Different
With Southern Transformers, there are no unknowns. Every transformer is designed, built and rigorously tested in our Melbourne facility, giving customers complete confidence in its quality, compliance and long-term reliability.
This gives our customers:
- Fast turnaround when it matters, or accurate scheduled delivery for non-urgent projects.
- Best-in-market reliability with premium steel, copper and insulation systems.
- Full compliance with AS/NZS 60076 and 61558.
- Complete in-house testing with detailed FAT reports, GA drawings and schematics.
- A 5-year warranty and 25-year design life because we stand behind every unit we make.
- Direct access to our technical team, not offshore call centres.
Our focus is on long-term partnerships, not one-off transactions. Whether you need a single custom unit or a high-volume production run, Southern Transformers is built for quality, consistency and support.
Our Values
Safety First
We look out for each other and our customers.
Quality and Craftsmanship
We take pride in what we build.
Integrity and Accountability
We do what we say and own what we do.
Customer Commitment
We listen, deliver, and exceed expectations.
Community and Growth
We grow together and contribute to something bigger.
Start Your Next Project With Southern Transformers
Looking for smarter, safer ways to support your operations? As one of Australia’s leading providers of custom transformer solutions, we’re here to help you get what you need, when you need it. Reach out to our team today to get started.
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