Leonardo fitted with backup power from Zest Weg Group


As Sandton anticipates the completion this year of the Leonardo, the top-end mixed-use skyscraper being constructed by Aveng-Grinaker LTA, Level 1 BBBEE-rated Zest WEG Group has supplied generator sets to keep lights on during outages. The iconic structure, that will dominate the skyline as the tallest building in Africa,  is being built for 75 on Maude (Pty) Ltd, a partnership between Legacy Group and Nedbank Limited.

According to Craig Bouwer, projects and product manager at Zest WEG Group genset division, the commissioning of the units was undertaken in the first quarter of 2019 with practical completion expected to be reached in the second quarter of 2019. This follows the original awarding of the tender in November 2017.

“We are proud to have designed, manufactured and supplied the two 2,000 kVA, 11 kV generator sets which we are installed in the Leonardo’s dedicated plant room on ground level,” says Bouwer.

“Our contract included delivering the units to site and placing them in position, which was done in September last year. We were also responsible for the complete installation, testing, commissioning and handing over to the client in full working order.”

The gensets will provide the building with emergency power backup and comprise prime-rated Mitsubishi-powered diesel generators coupled to WEG alternators. To reduce noise levels to local council requirements, Zest WEG Group supplied and installed inlet and outlet splitter attenuators. The fuel storage and transfer system ensures eight hours of operation, with bulk and day fuel tanks installed in compliance with local fire regulations.

The company also installed medium voltage (MV) generator protection and a control panel, as well as a main MV distribution panel for the building, comprising six tiers for all incoming supply and feeder breakers. All the related cabling for the MV and low voltage (LV) reticulation were also provided for the generator sets, fuel system and auxiliary control equipment.

Significantly, Zest WEG Group holds a Construction Industry Development Board (CIDB) rating of 6EB for electrical engineering work in buildings, as well as a 9EP rating for infrastructural electrical engineering work.

“We conducted full in-house MV testing of the system at our modern Cape Town facility before delivery to site,” Bouwer says. “We were assisted by our transformer division with the supply of three 500 kVA, 11 kV to 400 V step-down transformers to enable load testing at 400 V. This allowed us to conduct functional and load tests on the generator sets in our workshop, testing them individually as well as in full synchronisation and load share operation.”

Bouwer adds that the location of the generator plant room and the physical size of the generator sets meant that the generator sets could not be installed as fully assembled units.

“This challenge was overcome by disassembling the generator sets prior to delivery and re-assembling them in the generator plant room,” he says. “Due to the weight of the equipment, special rigging equipment was required inside the plant room to facilitate the re-assembly process.”