Electricity and Control November 2022

DRIVES, MOTORS + SWITCHGEAR

of MV switchgear and its tolerances for floor levelness. The buildings are designed for more than thirty years of service and have a track record to back this up. Specific attention is given to explosion venting, fire detection and suppression. Lux simulations are done for each room to ensure statutory lux levels are met or exceeded. Rooms are positively pressurised and HVAC systems are designed around the heat outputs of the equipment installed in the buildings. The thermal performance of the buildings is designed to be superior to that of brick and mortar construction, with the possibility of passive buildings (no net heating or cooling requirements), depending on the primary equipment installed. Pre-fitted walkway hand rails and stairs are also part of the standard offering with the option of self-lifting buildings that remove the need for site cranes. However, the most important benefit is that all electrical and C&I installation and commissioning can be carried out in main business centres rather than harsh site environments. □

for sites around the world for the past 40 years. Efficient Engineering is not constrained by what convention would say is a large load for transport. It is this ‘nothing is too big to make or move’ approach to building bespoke mega structures for land transportation that unlocks the electrical and C&I engineers’ ability to control their aspects of the project. Importantly, this approach allows for a parallel construction path, removing most of the sequential reliance entailed in site-based execution. The key is to have buildings that are custom-built around the equipment they will house, rather than trying to force equipment into a standard building container. Clearances should not be compromised and every combination of equipment requires a bespoke solution. If one is going to challenge convention, the alternative needs to be superior, as well as saving money and time for the project. Core to these buildings are the custom-designed base frames, which are made to match the equipment that will be installed on themand to accommodate the deflection criteria Above and right: The installation of substations and MCCs, including testing, integration and commissioning, also calls for highly specialised skills.

For more information visit: http://jbswitchgear.co.za/

Cost savings and benefits The following costs are based on the rounded numbers from a major mining project on which JB Switchgear was the Lead Electrical Engineer. The project’s basic approved budget for the Electrical and C&I delivery was a little over R500 million, with a provision for R11 million for substations and MCC build ings (only 2% of the budget). By making use of large, custom ised, modular buildings built offsite and moved to site post the installation and commissioning of all the equipment internal to the buildings, the overspend on the ‘traditional brick’ building budget was a little over R3 million. However, by removing the need for any of the electrical and C&I contractors to travel to site to install, integrate, test and commission the more than R100 million worth of equipment

designed for those buildings, there was a saving on the electrical and C&I budget of more than R80 million. This was mostly due to almost all the associated P&G costs being avoided, a reduction in commissioning time and no spend of the contingency budgets. Perhaps more significantly, the project was operational five months ahead of schedule. The early delivery alone realised more than 1.4 million tons of additional iron ore for the mine, and the early closure of the construction site. This had financial benefits for the company that exceeded a billion rand. It seems clear that there are alternative, simpler and cost effective solutions to working on site, which just require a logical mind shift.

12 Electricity + Control NOVEMBER 2022