Marthinusen & Coutts (M&C) and ACTOM Turbo Machines recently completed the refurbishment and return to service of the rotating machines forming the heart of SABS’s world class National Electrical Test Facility’s (NETFA) High Power Test Laboratory, just outside Johannesburg.
The High Power Test Laboratory can generate up to 40 kA and 14 kV high power surges for short-circuit and internal arc testing – among other tests. There are only a handful of similar facilities in existence globally, using highly specialised 85 MVA 3000 rpm BBC Oerlikon generators to produce the very high currents and voltages required.
The work on these units required great skill, experience, dedication, meticulousness and infrastructure which M&C and ACTOM Turbo are known for in the industry.
The refurbishment of the equipment for the laboratory, which had been out of action for more than 5 years, was performed between November 2019 and August 2020 – with much of this being carried out during the tough conditions of the Covid-19 Lockdown. The refurbishment was for the lab’s three main drivetrains, consisting of two 85 MVA 14 kV 3000 rpm generators driven by 1 MW wound rotor induction motors and one exciter drivetrain comprising an 800 kW 1000 rpm drive motor driving two DC generators supported by a 12.5 t flywheel.
“The project is a good example of our division’s electromechanical full solution offering and project management capability, giving the customer the peace of mind of having a single service provider ultimately responsible for their project,” commented Mike Chamberlain, M&C’s Commercial & Marketing Executive.
The full scope of work undertaken by M&C and ACTOM Turbo was:
- The removal, refurbishment and recommissioning of the two 85 MVA generators, drive motors and all the exciters.
- On-site refurbishment of the liquid resistance starters.
- Repair and servicing of the lubrication system.
- Repair and servicing of the ventilation system.
- Servicing the de-watering pump system.
- Refurbishment of switchgear components, bus bars and bushings.
- Cleaning and painting of the High Power Testing facility.
- Numerous additional aspects that arose during the recommissioning of the plant.
NETFA Consist of three laboratories i.e. Short Circuit, High Voltage and Materials / Installations with each of these laboratories being divided with a number of tests areas. The High Power test laboratory is just one of three test facilities at the Short Circuit, the other two being a 10kA Temperature Rise Plant, 10kA Short-Circuit Plant, and a High Current 100kA test lab. The High Power test laboratory is also one of only three such facilities globally, and it is unique in being the only such facility located at an altitude substantially above sea level.
The world-class NETFA facility is now fully operational again, ready for testing the following products:
- Power and distribution transformers
- Medium voltage switchgear and control gear
- High voltage fuses
- Prefabricated substations
- Medium voltage flameproof plug-socket assemblies
- Substation conductors and accessories
- High voltage switches
- Power cables
- Medium voltage terminal boxes
- Overhead line fault detection devices
- Current and voltage transformers
- Earthing and short-circuiting cables.
ACTOM Switchgear has already been making extensive use of the High Power testing lab since its return to service by M&C. Greg Whyte, Switchgear’s Design and Development Manager, said the importance of this facility to industry, both locally and abroad, cannot be underestimated.
Lucas Monyai, Senior Manager of NETFA’s Laboratory Services Division, and Seth Mnisi, Manager of the High Power testing laboratory, complimented M&C and ACTOM Turbo for completing the project in difficult circumstances and for going well beyond their original scope to address unusual problems that arose during the recommissioning process.
They also commented on the excellent working relationship that developed between NETFA, M&C and ACTOM Turbo.