COROBRIK has evolved into a major South African manufacturer, distributor and marketer of clay bricks, clay pavers and a range of building materials. With factories around South Africa, Corobrik distributes in excess of five million products each day.
Corobrik’s Glencoe branch in KZN faced imminent closure due to the massive losses forced on the factory by Eskom’s brutal loadshedding schedules. As the branch is a major employer in the area, many people faced losing their jobs if the branch closed. The situation was dire.
Corobrik originally intended to install generators to keep production going during load-shedding, however, the company’s analysis revealed that the cost of installing the massive generators required to run their large motors (up to 160 kW each, and requiring tremendously high starting currents), in conjunction with the cost of diesel, would be as crippling as the cost of production standing still during load-shedding.
Pieter Vorster, Corobrik process control specialist who was involved from start to finish of the project – knew that the only way to bring down the starting current of the motors was to use variable speed drives. This reduction in start-up current would mean smaller generators could be installed.
Because electronic motor control is not Corobrik’s area of expertise, the company called in industry experts, Varispeed, to assist with implementing a solution. Corobrik has been a Varispeed client since well before 2013.
Varispeed specialises in industrial and commercial motor control and automation solutions and has a proven track record of expertise, reliability, superior service and competitive turnaround times. The company is the sub-Saharan African partner and distributor for global brands including Yaskawa, Solcon, Magnetek, V-Drive Plus and Alpha Series and its product portfolio consists of low and medium voltage variable speed drives, soft starters, motion, control and electric motor solutions backed by warranties and 24-hour support and service.
The solution
Relying on Varispeed’s variable speed drives to reduce starting currents, Corobrik installed smaller generators than it originally envisaged.
Varispeed installed four Yaskawa GA700 drives, each with a bespoke panel: two per generator, one on the extraction fan, one on the flue gas fan, one on the pug sealer, and another on the extruder.
The GA700 is a versatile AC drive for industrial applications with great flexibility, small dimensions, and built-in features allowing for effortless integration into nearly any application.
The outcome
The drives substantially reduced the starting current of the motors. Vorster gives the following example: “On the hot air fan, I used to start up with peak currents of over 1,000 A. Now I’m starting up with peak currents of about 300 A.”
Said Garth Cuenod, Varispeed senior technician KZN: “When we connected the drives they worked so well the client was amazed at how much more production they were getting out of the plant now that the motors were running more efficiently.”
Bongani Mtetwa, Varispeed external sales engineer KZN says: “I went back to Glencoe after the installation and their Branch Manager – Francois Aveling – said to me with a big smile, ‘We are saving about 450 Amps per month which means not only are we saving on electricity and diesel, we will also be able to approach the municipality for a concession because we are saving Eskom so much money!’
“We are so excited to have put our heads together with the Corobrik team to come up with this solution,” adds Mtetwa.
“I’m actually going to be doing the same method with another plant in Johannesburg using approximately nine inverters,” says Vorster, confirming that the solution has been extremely beneficial for the Corobrik Glencoe branch, keeping production going during day and night shifts no matter the status of the Eskom supply – at vastly reduced consumption and cost.
