Tag Archives: Zest WEG Group

ZEST WEG GROUP HELPS FARMERS FIND GOOD ‘GROUND’ – ELECTRICALLY

According to Zest WEG Group, there are misconceptions around what constitutes ‘earth’ (or ‘ground’) and ‘neutral’ connections and not understanding the differences can create serious problems when connections are made from on-site transformers or other sources. This more often than not leads to earth leakage systems underperforming and compromising the safety of the equipment and operators.

Johan Breytenbach, transformer sales specialist at Zest WEG Group, says that the neutral connection in an electrical installation is designed to carry current all the time, while the earth connection is only supposed to carry current for a short period to trip your protection switch.

“Where this is not understood and the installation is not done correctly, the trip system will not work properly. In addition to this, stray currents are created that could cause other problems,” he says.

Experience has shown that many farmers use the neutral connection as the earth when they do an electrical installation, and this is not correct. Current carried on a grounding conductor can result in significant or even dangerous voltages on equipment enclosures. For this reason, the installation of grounding conductors and neutral conductors is carefully defined in electrical regulations.

In alternating current (AC) electrical wiring, the earth is a conductor that provides a low impedance path to earth so that hazardous voltages do not find their way to the equipment. Under normal conditions, the earth connection does not carry any current. Neutral, on the other hand, is a circuit conductor that normally carries current back to the source.

Neutral is usually connected to earth at the main electrical panel or meter, and also at the final step-down transformer of the supply. Neutral is also the connection point in a three-phase power supply to connect cable termination in order to gain single phase power. In a three-phase circuit, neutral is usually shared between all three phases, with the system neutral being connected to the star point on the feeding transformer.

Earthing is therefore a vital part of electrical installations to ensure that circuit breakers will trip under fault conditions. Safe and legal installation needs to start with the selection of the right transformer, with a star configuration to allow the connection to the neutral point. Installation by a qualified and experienced technician is then ideal, to ensure optimal performance.

The correct earthing or grounding of electrical currents has a number of important benefits apart from the main concern around safety. It protects equipment and appliances from surges in electricity – commonly from lightning strikes or power surges – which bring dangerously high voltages of electricity into the system. Good earthing will ensure that excess electricity will go into the earth, rather than damaging equipment.

Zest WEG Group’s product line-up includes low and high voltage electric motors, vibrator motors, variable speed drives, softstarters, power and distribution transformers, MCCs, containerised substations, mini substations, diesel generator sets, switchgear and co-generation and energy solutions as well as electrical and instrumentation engineering and project management services.

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.”

ZEST WEG GROUP’S NEW CEO LOOKS TO GROW AFRICA FOOTPRINT

As part of its ongoing growth plans, Zest WEG Group will continue to focus on opportunities in more African countries, according to its new chief executive officer, Siegfried Kreutzfeld.

With 40 years of service in the global WEG Group, Kreutzfeld brings a wealth of industry experience to the top job at the South African business, which he joined in January 2019. He was most recently the managing director of WEG China.

“WEG has a very simple strategy: we believe in continued growth on all continents,” he says. “This is achieved by maintaining close relationships with all our customers and ensuring that we deliver quality products. We underpin all this by our high levels of service and support.”

Established in South Africa to create a strong national footprint, the Zest WEG Group has grown steadily into other Africa countries. With its responsibility for the sub-Saharan market, it operates branches in Ghana, Tanzania, Mozambique and Namibia. The group also has competent partners in countries like Angola, Botswana, Zimbabwe, DRC and Zambia. Today, the Zest WEG Group ranks among the top five operations in the global WEG Group.

“Many of our products are well established across the continent,” he says. “However, we believe there is growth potential with both mature products – such as low voltage motors, high voltage motors, and drives and switchgear – as well as with other products we manufacture locally such as transformers, motor control centres, panels and generators.”

Kreutzfeld highlights that major opportunities exist with premium efficiency products across the range, including WEG IE3 motor and WEG CFW drives.

“Also key to the Zest WEG Group’s growth potential is our ability to offer a fit-for-purpose integrated solution,” says Kreutzfeld. “This is available across all sectors, but especially in power generation, electrical infrastructure and mobile power and energy solutions. We will also be introducing WEG solutions for renewable energy applications.”

The wide range of products in Zest WEG Group’s market offering are relevant across a broad sector of industries including mining; petrochemical; agriculture; water and wastewater; paper and pulp; sugar; and energy – including traditional coal fire power plants and renewable energy.