About
Engineering excellence since 2015.
Based in Cwmbran, South Wales - designing and manufacturing transformers for utilities, industry and renewables.
South Wales Transformers was established in 2015 to provide high-quality, competitively priced transformer solutions for the UK energy sector. Based in Cwmbran, South Wales, we design and manufacture a comprehensive range of oil-filled distribution, power, and dry-type transformers serving utilities, industrial clients, and renewable energy developers.
Our team brings together extensive experience in transformer engineering, manufacturing, and project delivery. Every unit we produce is designed to meet or exceed current international standards, including IEC 60076 and EU Ecodesign Directive requirements.
Our principles
Three principles. No compromise.
Client-focused service
We work directly with clients to understand technical requirements, site constraints, and programme timescales. Whether a standard catalogue unit or a bespoke design, we provide clear guidance and responsive communication.
Efficiency and sustainability
Our range includes amorphous core transformers that significantly reduce no-load losses, supporting clients in meeting energy efficiency targets and reducing long-term operating costs.
South Wales engineering heritage
South Wales has a long and distinguished history in heavy engineering, steelmaking, and electrical manufacturing. We are proud to continue that tradition with modern techniques and a forward-looking approach.
Technical rigour
Every transformer is engineered to precise specifications, manufactured under controlled conditions, and subjected to comprehensive factory testing before despatch. We do not compromise on materials, workmanship, or testing.
Capabilities
From 100 kVA to 500 MVA.
We supply transformers across a wide voltage range - from 380 V to 500 kV - including oil-filled distribution, medium power, dry-type and cast resin, and special-purpose designs such as rectifier, reactor, earthing, and mobile transformers.
Distribution
Oil-filled, amorphous-core, and pole/ground-mounted units up to 5,000 kVA, 36 kV.
Power
Small and medium power transformers from 5 MVA up to 100 MVA at 500 kV.
Dry-type
Cast resin transformers up to 6 MVA, 36 kV with class F or H insulation, IP00 to IP33.
Special
BESS, K-rated, traction, reactors, earthing, phase-shifting and mobile units to specification.
Tap changing
On-load (OLTC) or off-load (DETC) options across the full range.
Tank arrangements
Conservator, sealed hermetic, or gas-cushion configurations.
Beyond manufacture
Nationwide and worldwide delivery, professional installation, commissioning, and lifetime maintenance & repair support.
Working with us
From DNOs to major contractors.
We serve clients across the United Kingdom — Distribution Network Operators, major contractors, independent consultants, and end users. Dependable equipment, competitive pricing, and professional service on every project.
Discuss your requirements.
Talk to our engineering team about your transformer rating, voltage, mounting arrangement and delivery timescales.