Leeds Transformer Co. Ltd
Manufacturers of Bespoke Transformer and Rectifier Units. Established 1947.

Units 1-5, Larchfield Road, Leeds, West Yorkshire, LS10 1QP, U.K.  

Phone: (044) (0)113 2705596, Fax: (044) (0)113 2721458

sales@leedstransformer.co.uk or sales@leedstransformer.com


Company Reg. No: 813216,     VAT No: GB 170080595

D&B D-U-N-S® : 212173157

Standard Industrial Classification of Economic Activities Code (SIC 2007): 33140


 Products   Projects   The Company   Procedures   RoHS/REACH 

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Product Range

Oil Cooled and Air Cooled Transformers

Single and Three phase, double wound (isolating) transformers up to 800 KVA

Maximum service voltage: Air cooled up to 11kV. Liquid cooled up to 33kV

Auto-transformers in equivalent frame sizes to our double wound range

Auto-transformers for motor starting duty, by the Korndorffer method

British Gas / Transco / National Grid approved isolation and supplies transformers

Buck / Boost Transformers

Combined LV. transformers and MCB. distribution cubicles for safety supplies

Custom manufacture of transformers to specifiers requirements and assembly with associated control equipment. Enclosures may be fabricated to match available awkward spaces, or made to match with existing equipment

Earthing transformers

Energy Saving Systems

Ex d, Ex o, Ex e, Ex n, Ex m, Ex i, Instrumentation and power transformers for use in Zone 1 and Zone 2 hazardous areas, manufactured to BS EN 60079 with IECex & ATEX certification

Epoxy cast resin encapsulated transformers for use in the arduous environments of oil rigs and other areas with high levels of humidity and vibration, some of these designs carry military seismic / seizmic approval

Harmonic Current Reduction Transformers

K-Factor transformers, designed to reduce the heating effects of harmonic currents induced by "K" Factor, non linear loads

Oil immersed transformers: Free breathing and hermetically sealed type.Synthetic (Xiameter / Dow Corning® PMX-561 Silicone & Midel 7131) liquid filled units

Power reduction systems for lower energy useage

Renewable energy (Solar, Hydro-electric, Wind or Biomass) Voltage & phase conversion. Grid feed from water and wind powered turbines

Specialist Transformer units and systems for Ministry of Defence (MOD) for NATO projects and other similar applications

Single and Three phase, double wound transformers up to 800 KVA

Static balancer transformers for the provision of a neutral conductor at distant locations

Thyristor controlled power transformer units for the glass smelting & glass flake making industry

Transformers to British Rail, BRB, BREL,Network Rail, & RailTrack Specifications

Transformer-Rectifier Units for D.C. power supplies

Transformers with thyristor control systems

Voltage Increase and Reduction Transformers

Voltage measuring and metering transformers with primary windings up to 15 KV. Single phase or three phase

Winding configurations to Delta/Star (Delta/Wye), Interconnected Star (ZigZag), Auto Wound, Phase Shifted Scott, Two Phase & Tapped Delta

Combinations of many of the above and others

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A Selection of Previously Completed Projects

500kVA Midel® 7131 Fluid Filled Hazardous Area Zone 1 Transformers
to Ex db[ia] eb ob IIB T3 Gb
RBV Engineering for SAT Engineering / ADNOC Offshore

450kVA Dow Corning® Xiameter PMX-561 Silicone Fluid Filled
Hazardous Area Zone 1 Transformers to Ex d e o [ia] IIB T3 Gb
RBV Engineering for SAT Engineering / ADNOC Offshore

19.3kW Low Voltage High Current Midel® 7131 Fluid Filled
Hazardous Area Zone 1 Transformer / Controlled Thrystor Rectifiers
to Ex db [ia] ec oc IIC T3 (Tamb=45°C) Gc
Cumberland Electrochemical Limited for Idemitsu
Sao Vang and Dai Nguyet Development Project

96.25kW Low Voltage High Current Air Cooled, Transformer / Controlled Thrystor Rectifiers
Cumberland Electrochemical Limited for Statoil
Johan Castberg

Totally enclosed, air cooled,isolating transformers sealed in special stainless cases suitable for use in food-processing.
Nestlé (Rowntree-Mackintosh)

Seismically qualified, cast in resin isolating transformers for R.N.A.D. Coulport Nuclear Facilities.
Hawker Siddeley Power Engineering

Heavy Current Transformers & rectifiers to support glass flake manufacturing

Cast in resin, seizmically qualified, isolating transformers for U.S.N.A.D. Faslane Nucular (Nuclear) Facilities
Westinghouse Systems
Kennedy &Donkin

Near Silent replacement for Houchin aircraft power supplies, for Royal Navy Helicopters.To BS 2G219. (ISO6858)
How Engineering for HMS _____

Air-cooled H.V. transformer for firewater pump auxiliaries on board an off shore platform
Amerada Hess Ltd
Brown & Root

Step-Up - Step-Down Transformer Equipment for long distance Submarine Power Transmission
Fugro Aberdeen

Air cooled voltage matching and transient attenuation transformers of various sizes up to 250 KVA for the very demanding requirements of their Lithrone Perfector series of sophisticated graphics printing machines

Sealed type, non-flammable fluid filled H.V. Power transformers, with windings specially braced against vibration for use on board the Gypsum Reclaimer Machines, for the Flue Gas De-sulphurisation Plant at Drax Power Station
PWH Materials Handling - For National Power

Site investigation and manufacture of various sealed type, non- flammable fluid filled, transformers to replace P.C.B. filled units supplying precision D.C.drives
British Steel plc, General Steels Division, Scunthorpe (now Liberty Steels)

Sealed type, non-flammable fluid filled, jack-up supply, isolating transformer to be used in a hazardous area for the interconnection of two floating offshore platforms - For Ranger Oil
H & G Engineering

Sealed type, non-flammable fluid filled, high Spec. antennae isolation transformers with high voltage interwinding insulation.
U.S. Department of Defense (Defence)

Air cooled, isolating transformers for U.P.S. systems constructed using low smoke and fume insulation materials for Raytheon Radar, B.M.E.W.S. III Upgrade at RAF Fylingdales
Alan Electrical
W.S. Atkins & Partners

Site investigation and manufacture of transformer-rectifier unit to replace old mercury arc equipment supplying D.C. operated travelling cranes from H.V. supply. Unit tailored to fit the available space alongside the old equipment
British Steel plc. Bryngwyn Works. Swansea (now Tata)
South Wales Electricity

Assorted transformers for instrumentation, small power supplies and voltage optimisation. The majority suitable for use in "Zone 1" Hazardous Areas. All outdoor units supplied complete with galvanised (galvanized) weather protecting hoods and mounting frames
B.P. Chemicals Ltd. Acetyls A5 Project, Hull
Davy McKee

Air cooled, isolating transformers for U.P.S. Systems. Constructed using low smoke and fume insulation materials, together with assorted transformers for low power and auxiliary equipment supplies. For Building 700, RAF / USAF High Wycombe, England (Nuclear Hardened Facility). All units manufactured to withstand the required level of seismic disturbance
Ottermill Switchgear, N.G. Bailey
Oscar Faber

Various Transformers for small power and low voltage supplies at Terminal 4, Heathrow Airport
N.G. Bailey & ABB
McLellan & Partners

Manufacture of many Class ‘H’, Transformers, and encapsulation into 1060 HeliMiner continuous mining machine's Transformer boxes. These machines are subject to high temperatures, constant vibration and have very tight design parameters.
DBT / Allenwest Wallacetown for Cleveland Potash

Design, manufacture and supply ground electrical supplies plinths for GKN Westland / Boeing AH-64 Apache Attack Helicopters. A very high spec. project. Design standards to Electrical Supplies For Aircraft BS 2G219. (ISO6858)
GKN Westland Helicopters & British Army Air Corps, Via Southern Electrical Contracting (SEC)
White Young Green

A range of EEx-d & other transformers, some complete with Neutral Earthing Resistors, Earth Monitoring equipment & Castell Safety, Trapped Key safety interlocks
BP Hoton Platform, via JCE Aberdeen
Consultant / Facilitator: Halliburton, Brown & Root

Manufacture to very tight electrical and mechanical constraints, portable voltage matching transformers, with LEMP / NEMP suppressors and seismic / seizmic protection for the ASTOR project
Customers: Ratheon, via Marshall SV

Zone 1 Hazardous Area Transformer c/w Areva / Micom Relay in Ex e chambers, Impulse testing by NaREC, Certification by SIRA, Inspected by Bureau Veritas.For the Pohokura Oil Field, North Taranaki, New Zealand
Customers: Shell Todd Oil Services via Fitzroy Engineering Group

Portable Transformer / Rectifier for testing Formula 1 racing car features
Customers: Williams Grand Prix Engineering

Various 1230KW to 2100KW Korndorffer Auto Start Transformers
Customers: Boddington Power Controls, for Meiden Pacific (China) Ltd

Three Phase to Single Phase, Conversion Transformers.
Customers: Petrofac (Sharjah, UAE) for Kuwait Oil Company (KOC)

Xiameter / Dow Corning® PMX-561 Silicone Fluid Filled Hazardous Area Zone 2 Transformer to Eex o e d IIB T3 &others. From 50kVA to 1600kVA
Customers (Technology Partners): Swift Energy Sdn Bhd (SENERGY), Malaysia, for Sarawak Shell Berhad

Manufacture of 2 off 550 KVA (Ex o e n [ia] IIC T3) HVAC Transformers, On Board FPSO Espirito Santo, For BC10 Field
photo kindly presented for our website, by SBM Offshore Inc.
Customers: SBM Offshore Inc., operated by Royal Dutch Shell (RDSA) with ONGC Campos Ltda


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The Company

Leeds Transformer Company was established in 1947. It has, since then specialised in the manufacture of bespoke, custom build, low loss, energy efficient, high quality transformers and transformer rectifiers. These are designed and built with pride by our dedicated, highly skilled team at our works in Leeds,West Yorkshire,England.
Our transformers and rectifiers range from 1 to 800kVA and are built to British and International standards with, short lead times, quality assurance traceably and conforming to the BS EN ISO 9001:2008 Standard, and if needed, documentation (Quality and Technical IOM Manuals with CAD drawings). Liasing with consulting engineers and specifiers to produce the 'right answer' for the project.


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Fully detailed, priced quotations, detailing technical and administrative arrangements, and terms.

In house design utilising ProgeCAD® (AutoCad® Compatible), Microsoft® Word, Excel and 'In-House' design tools and data.

Manufactured to Lloyds Register of shipping, BS 171 – IEC 60076 – IEC 60726 – IEC 60079 where applicable.

Computer controlled Sales and Purchase, with Quality, Stock Procurement and Control, Conforming to the BS EN ISO 9001:2008 Standard, using Filemaker® database system.

All instruments, precision tooling and lifting equipment certified & calibrated.

In House automated cutting of Electrical grade, grain orientated, low loss steel cores, in straight and mitred configurations.

Clean, ferrous free, winding environment for Prime Quality, UK sourced, electrical grade, copper coils.

DuPont™Nomex® Paper and Pressboard, Weidmann Whiteley Elephantide, and Presspahn Insulation materials

Insulation improvement by drying out, vacuum impregnation, and full thermal curing of Advanced Electrical Varnish (AEV) solventless varnish, in a Airflow oven, tested at each stage by Calibrated Megger, Fluke and Chauvin Arnoux Instruments.

Extremely Robust techniques employed in designs of Coil to Core, and Transformer to case assembly.

Fluid coolants utilised are, M & I Materials Ltd, Midel 7131®, Xiameter / Dow Corning® PMX-561 Silicone Fluid, Transformer Insulating Oil BS148: 2009 & IEC 60296:2012.

Hermetically sealed units issued with inert BOC dry nitrogen blanket above fluid.

Routine, and temperature rise (type) testing IAW BS EN 60076.

Also available, Impulse testing, ATEX / IECEx Certification by SIRA/CML, Inspection by Bureau Veritas (BV), Det Norske Veritas (DNV), Lloyds Register of Shipping (LRS), American Bureau of Shipping (ABS) and/or similar authorities.

CE marking in accordance with European directive 2006/95/EC and UK Governments UKCA marking

Casing, Crating, Packing & Shipping to international standards where required. Transportation by groupage, door to door, sea and air.

Full documentation packages available including, but not limited to 'Installation, Operation and Maintance' (IOM) and 'Certification' Manuals


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Leeds Transformer Company's RoHS and REACH Compliance Statement.pdf


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Terms and Conditions

Leeds Transformer Company's Terms and Conditions of Sale.pdf


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Find Us

By Road
Near the Junction of the M1, M62, M621 and local to the A1(M)
Map of Leeds Transformer Co. Ltd, Unit 1-5, Larchfield Raod, Leeds LS10 1QP

Set SatNav to. LS10 1QP, Larchfield Road, Units 1-5

Mapcode. GBR BNR.BF (mapcode.com)

What3Words. PRONE.PROOF.MAKES (what3words.com/prone.proof.makes)


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Nearest Airports
Leeds Bradford Airport, Yeadon (LBA) - 13 Miles - 21 km LBA
Doncaster Sheffield, Robin Hood Airport (DSA) - 43 Miles - 69 Kilometres DSA
Manchester, Ringway (MAN) - 54 Miles - 86 km MAN
London Heathrow Airport (LHR) - 194 Miles - 312 km LHR
London Gatwick Airport (LGW) - 235 Miles - 378 km LGW


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Opening Times

Opening Times (Printable)


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The above is a 'short form' of our capabilities - if we can help you, please contact us.
There will always be one of us on hand.

Nigel Wilkes (Managing Director)

Andrew Longley (Works Manager & Designer)

Emily Mann (Company Secretary & Account Manager)

Marcin Janicki (Designer)


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The company does not have a rapid employee turnover, however, occasionally we do have openings (job vacancies). If you live in the local area, or perhaps Wakefield, Pontefract, Castleford or other commutable areas, are a winder or have lengthy experience in Transformer winding or assembling, and are seeking jobs with a small friendly team, why not contact us.

Any other skills that you think may be of use to us?? We are happy to tailor a job around a particular person or expertise.

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Information Security, Privacy & GDPR

Policy Statement - General Data Protection Regulation 2018 (GDPR)

Leeds Transformer Company Ltd is committed to high standards of information security and privacy. As a company, Leeds Transformer places a high priority on protecting and managing data in accordance with accepted standards and complies with all applicable General Data Protection Regulation 2018 (GDPR) regulations. The protection and respect of the organisation, clients, staff and other individual's personal information/rights is paramount, therefore complying with the law and following good practice is essential. Training and support is provided to the staff who handle personal data, so they can act confidently and consistently. In addition, Leeds Transformer Company Ltd has voluntarily registered with the Information Commissioners Office and given all the appropriate notifications.

Closed Circuit TeleVision (CCTV)

Leeds Transformer Company uses closed circuit television (CCTV) images to assist in providing a safe and secure environment for its employees, visiting clients, customers and suppliers. The purposes for the installation of CCTV systems include the following:- The assistance in the prevention or detection of crime or equivalent malpractice, The assistance in the identification and prosecution of offenders and the Monitoring of the security at the Company’s business premises.
For further information please contact sales@leedstransformer.co.uk or phone +44 (0)113 2721458

Leeds Transformer is a Registered Company with the Information Commissioners Office as of May 2018 Reference Number ZA360973.

Website Privacy Policy

Leeds Transformer Company's Website Privacy Policy.pdf


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A Bit of History

Max Harris and Walter Townley started "Electro Motor Rewind Service", repairing electric motors, transformers and vacuum cleaners in a four roomed 'lock-up shop', in Meadow Road, Leeds, on the 1st September 1947, officially registering the company on the 5th September  1951.

With the introduction of Bernard Coates as a Director, the 'firm' took on transformer design and manufacture with a change of name on 9th July 1964 to Electro Motor Rewind Service & Leeds Transformer Co.

The Transformer Company employed more personnel and eventually moved to the present purpose built factory in September 1965.

Walter Townley died in 1968, and is remembered as a good friend.

The Transformer side of the business performed particularly well, and the rewind side was dropped, with a final change of name to the present Leeds Transformer Company Limited, on 31st July 1972.

George Steele and Chris Jones - long term, electrically qualified, employees, joined by Mal Anderson, a Mechanical Engineer, took over the ownership from Max in 1986.

A dedicated 'Winding workshop' was added in 1989.

Nigel Wilkes, another long term employee, who is qualified in Electrical & Electronic Engineering, in addition to qualifications in Management, took over the company in September 1999. Nigel is now the majority shareholder and Managing Director.

A centrally heated stores was built in 2000.

Max Harris, sadly, died suddenly in October 2005, aged 92. He was a director for 58 years, and maintained a keen interest in the Company to the end. His departure was the end of a significant era, and he is very much missed.

Further expansion, early in 2009, into an adjacent factory, taken on as a warehouse, enabled reconfiguration of the old 'Stores' into a 'Ferrous Workshop'.

September 2009 saw our office and canteen structure replaced with purpose designed canteen, Ladies & VIP toilet & 'Yard Office' below, with Admin, Design and MD offices above.

July 2014 saw the installation of an Overhead Articulated Bridge Crane, in the Main Workshop.

With our evolving production lines, it became apparant that we needed a larger floor area and greater height. To satisfy this requirement, in January 2020 we took on the rest of the factory adjacent to the 2009 warehouse. This has given us a modern, efficient, well appointed, comfortable factory which is tailored to our needs.

George Steele, Chris Jones & Mal Anderson, all retired fully in September 2020 having served the Company for over 150 years between them.

Eligible employees continue to be sponsored through relevant Foundation Degree and BTEC Nat.Cert. courses.


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Leeds Transformer Co. (formerly, 'Electro Motor Rewind Services') Office and Workshop, Meadow Road, Leeds
Circa 1953

Leeds Transformer Company is a Limited Company Registered in England and Wales -Registration Number: 813216
Registered Office: Leeds Transformer Company Ltd. Units 1-5, Larchfield Road, LEEDS, UK, LS10 1QP

Directors: Lynn Wilkes, Nigel Wilkes (Managing Director)

Constructed and maintained by Nigel Wilkes. Website search engine optimisation technique © Nigel Wilkes 2021..