011 794 9498 sales@redmetal.co.za

Power Transformer Division

Red Metal Mining has been active in the cast resin market since 2006. Due to our clients’ ongoing need for oil type transformers, we have established a manufacturing facility for oil type transformers for both surface and underground application.

Red Metal Mining Group is pleased to announce the opening of our new RMM POWER TRANSFORMERS division which will be manufacturing oil type transformers and substations.

Our manufacturing facility in Chloorkop, Edenvale, is housed in a 2500m2 factory with a 10 ton overhead crane.

All manufacturing is done locally in South Africa and we are rated a Level 2 BEE Company.


Product Range

Product range currently offered:

50kva to 5MVA up to 33kv

with plans to upgrade to 10MVA by July 2022

All transformers are fully tested in our state-of-the-art testing facility and comply with the following standards:

  • SANS 780
  • IEC 60076

We offer our clients:

  • Short delivery periods of approximately 6-8 working weeks depending on our manufacturing schedule
  • Option of using copper or aluminum for the transformer windings

We have invested in the latest Solidworks 3D Mechanical software packages as well as EPLAN Software to provide detailed Schematic Drawings and 3D visualization of the terminal boxes and cable wiring.

Our product range includes:

  • Distribution Transformers
  • Power Transformers
  • VPI Dry Type Transformers
  • PV Transformers
  • Converter Transformers
  • Rectifier Transformers
  • Auto Transformers
  • Single Phase Transformers
  • Minisub Transformers for surface and underground, complete with LV breakers and ring main units – SF6 <
  • Containerised Substations – custom built to client’s requirements


Routine testing on all transformers manufactured – SANS780 / IEC60076:

  • Measurement of winding resistances
  • Measurement of voltage ratio and check of phase displacement
  • Measurement of impedance of the load and losses
  • Measurement of no-load losses and no-load current
  • Separate source AC withstand voltage test
  • Measurement of insulation resistance
  • Tank effectiveness of sealing the transformer

We use the following testing equipment – SANS780:

  • 560kVA Alternator set – 50Hz/100Hz (Dual Frequency)
  • 500kVA Test transformer with varies voltages up to 33kV
  • 100Kva 80Kv 400v Separate source single phase transformer
  • Fluke 1777 Power Analyzer
  • Clamp on Current Transformer (1730)
  • BA80- 80Kv Portable Breakdown Analyzer for Oil Testing
  • BK Precision 878B RCL Tester (Resistance, Capacitance and Inductance)
  • TWA4OD 3 -Phase Winding Ohmmeters & Tap Changer % Winding Analyzers
  • True 3-Phase transformers Turns Ratio Tester
  • Fluke Multimeters
  • Elcometer Dry Film Paint Thickness Tester
  • MT95 -Sound Meter


Oil type transformer repairs/rewinding – SANS 780/IEC 60076

We refurbish/rewind all exiting types of oil transformers and minisubs at our facility with full documentation and a 12-month warranty period from commission. The coils will be rewound on our winding machines and tested accordingly. All transformer tanks will be sandblasted in-house, as well as wet sprayed and baked in the spray booth located at our premises.

On-site Services

  • Onsite Oil Purification: We also offer onsite oil regeneration/testing with our new oil purification plant mounted on a trailer to move to site. Our onsite team has years of experience and are well qualified and are available 24/7.
  • Duty & Performance: We offer performance in a single pass through the purifier at full flow rate.
  • Dielectric Strength: Improvement in dielectric strength up to 70kv with new oil.
  • Water Removal: From 50ppm down to less than 50 ppm in a single pass and down to 3ppm after two passes as measured by the ASTM Method D-1533.
  • Particulate removal: 98% of particles over 1 micrometer, or over 1 or 5 micrometers, as per your preference.
  • Gas Removal: From fully saturated with air (10 to 12% by volume) down to less than 0.1% by volume as measured by ASTM Method D-2945.
  • Design: Flow rate of 3000l/h with a vacuum booster for improved performance.
  • Transformer Audits: Performed onsite on your existing transformers can be beneficial to the lifespan of your transformers by doing regular oil sampling tests. Written reports will be drafted on each units tested.

For sales enquiries or more information, please contact our sales team.


Contact details

+27 (0)11 794 9498

Benita Stander
Sales Manager

Braam van den Heever
Business Development Manager

Phillip van der Walt
Proposals/Sales Engineer


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