Leaking transformer oil causes environmental harm and creates a serious fire hazard. To address this, most transformers have a bunding wall to contain leaking oil. A local company has developed a sophisticated minisub which is self-bunding. This means that no bund-wall needs to be built, making the installation of the minisub that much more quickly and cost-effectively.
Minisubstations (minisubs) can be defined as substations which comprise a transformer, low voltage and high voltage switchgear, connections and auxiliary equipment in an enclosure to supply low voltage electricity from a medium voltage network.
Every oil-filled transformer must be installed in such a way as to contain oil should it leak from the transformer. Transformer oil – especially mineral oil – is harmful to the environment and increases the risk of fire. Oil spills are largely due to slow oil leaks, attacks from metal thieves or vandals, or result from human error at the time of maintenance or installation. Bund walls allow for the containment of spilt oil.
ArmCoil, a rapidly growing electrical equipment company based in Roodepoort, west of Johannesburg, manufactures and repairs transformers, motors and other electrical equipment. The company recently developed an innovative minisub enclosure design which incorporates a bund wall and storage area for transformer oil should the transformer leak. This important feature helps the company’s minisubs to comply with environmental regulations, and also removes the need for oil clean-up mitigation equipment and procedures to be put in place when the minisub is installed.
ArmCoil’s Morne Bosch says that local content is important for the company, so it uses as much locally supplied equipment as possible in the construction of its minisubs. The minisubs are designed to be equipment agnostic, which allows the client to determine the brand and type of the RMU and switchgear to be installed.
The enclosures are designed to be robust and built to protect all the equipment they house and can also be ordered with built-in fire suppression units. They have strengthen skids and independently tested lifting lugs which, together with their build-in bund-wall, makes them totally mobile and quick to install and deploy. These locally designed and manufactured minisubs offer tamper-resistant features including a sophisticated door-locking mechanism which makes forcing the doors open virtually impossible. The minisub’s enclosure also offers IP65 rating, which offers dust-proof and waterproof protection.
Special features include a “flash chute” on the roof of the unit which will blow off in the event of an explosion inside the minisub guaranteeing operator safety; as well as pre-fitted lifting lugs and built-in skids which can be fitted with wheels should the client wish to be able to move the minisub without having to order a mobile crane or rigging team.
The units are designed to be used anywhere – including corrosive environments. The cabinets are made from either mild steel or 3C12 – a form of stainless steel – and treated with a special “coastal” coating which protects them from corrosive sea air. Their modular design makes the repair or upgrade of internal equipment easier and therefore less expensive.
Contact Morne Bosch, Armcoil, Tel 011 763-2351, email@example.com