classic | mobile



Rockwell technology optimises tyre processing plant in Port Elizabeth
1st Quarter 2019, Electrical switching & drive systems & components

Rockwell Automation’s Gauteng-based systems and solutions (SSB) team has executed two separate projects at a tyre processing plant in Port Elizabeth. The back-to-back projects will assist the manufacturer to maintain continuous and safe production.

The first project (the rubber mill feed project) included the design and implementation of a Rockwell Allen Bradley PowerFlex AC variable speed drive (VSD) solution, forming part of the manufacturer’s in-house optimisation project. It involved the addition of a two-roll rubber feed mill to aid in meeting the critical demand of downstream processes.

The second project (the Banbury mixer project) involved replacing obsolete drives for one of the plant’s Banbury mixers. Allen Bradley PowerFlex modular DC drives were implemented with a Rockwell Connected Enterprise approach.

Rubber mill feed project

This project entailed the expansion of the rubber feeding process by the addition of a standalone two roll feed mill. The rationale was to have redundancy in the event of a drive or mechanical failure. The new mill furthermore allows for variable speed operation, optimally feeding the calendaring process.

The scope of work included the design, construction and commissioning of a VSD panel for the 150 kW, 400 V AC feed mill motor. A PowerFlex 755 was chosen for this application. This allowed expansion by installing multiple digital I/O, feedback and safety option cards, with the additional benefit of on-board programmable logic.

Rockwell Automation implemented the control philosophy provided by the machine-motor integrator for the project. This included programming software functionality in the VSD using the on-board DeviceLogix and integrating speed control encoders with an Allen Bradley safety relay.

Banbury mixer project

The Banbury mixer project involved replacing four obsolete third-party drives and their panels used for one of the manufacturer’s Banbury mixers. The mixers are used to mix the raw materials that form the rubber compound.

The Rockwell Integrated Architecture-based solution, which allows for Ethernet enablement, replaced the older hard-wired technology. The migration of the safety and control of the mixer drives on to the newly installed GuardLogix safety PLC provides the ideal platform for future complete mixer control upgrades.

Two 0,75 MW total motors drive the mixer through a common gearbox. Essentially, four DC drives were replaced with a two-drive modular system using locally sourced Semikron SCR power modules interfacing to an Allen Bradley standalone DC Drive Regulator (SAR) module. This removes the requirement of having two drive interfaces per one motor, at the same time reducing system complexity, and minimised failure potential due to physical segregation and electrical isolation of power and control devices.

Each 0,75 MW DC motor is fed from a 30 degree phase shifted, 550 V AC dual supply, which makes up a 12-pulse drive. The PowerFlex DC SAR module is scalable up to four parallel power units, either regenerative or non-regenerative. A major safety net is provided with a PowerFlex SAR -based 12-pulse arrangement in that cross conduction (plus to minus) cannot take place between two regenerative SCR bridges. The scaling of voltage and current feedback to the SAR is fully programmable. It is thus also ideal for retrofitting applications where existing SCR stacks are re-used.

In the case of the Banbury mixer, any of the two identical SAR interfaces can be configured to be the master drive for the system. This prevents the dependency on one specific drive to always be available. One motor can be shut down and the machine operated at reduced capacity. There are no direct power connections between the two new drive panels, which are separate.

Interfacing with the third-party PLC was done through an Allen Bradley networked Point IO, communicating to the safety PLC and drives via a Stratix 5700 managed switch. This permitted sufficient network integrity to handle critical communications like safety I/O and load sharing between motors. Controlling all the electrical safety devices directly in the new drive panels resulted in an 80% field wiring reduction and also enabled pin-point fault-finding.

One of the challenges overcome was the tight time frame right through from order acceptance to project completion. Another was to remove the old and install and commission the new panels, working in a confined and raised electrical room together with the Rockwell Automation appointed installation company.

For more information contact Devo Pillay, Rockwell Automation, +27 11 998 1058,,

Supplied By: Rockwell Automation
Tel: +27 11 654 9700
Fax: +27 11 654 9702
Share via email     Print this page  

Further reading:

  • Flying motion
    2nd Quarter 2019, Beckhoff Automation, Electrical switching & drive systems & components
    A planar motor system of free-floating movers with six degrees of freedom.
  • A new era of automation control
    2nd Quarter 2019, Schneider Electric South Africa, Electrical switching & drive systems & components
    Schneider Electric’s new high end Modicon M580 Ethernet programmable automation controller (ePAC) features redundant processors, native Ethernet, and cybersecurity embedded into its very core.
  • A new servo motor
    2nd Quarter 2019, Tectra Automation, Electrical switching & drive systems & components
    The new MS2N synchronous servo motor range is Tectra Automations’ latest product offering to break new boundaries in the electric drives and controls industry.
  • VSDs drive cost saving in pumping systems
    2nd Quarter 2019, Zest WEG Group Africa, Electrical switching & drive systems & components
    WEG variable speed drives (VSDs) offer the agricultural sector the ability to reduce the operating cost on automated water collection systems with a reduction in motor energy consumption when the motor speed is reduced.
  • SEW-Eurodrive and Film Riggers help French Spiderman
    2nd Quarter 2019, SEW-Eurodrive, This Week's Editor's Pick, Electrical switching & drive systems & components
    Specialist rigging company, Film Riggers, was recently called upon to ensure the safety of Alain Robert, aka the French Spiderman, while he scaled a skyscraper in central Johannesburg to create an advertisement for an international tyre manufacturer.
  • Power solutions for load shedding
    2nd Quarter 2019, Electrical switching & drive systems & components
    From mines to factories and even the small business and residential sector, Cummins has a full range of alternative power solutions on offer.
  • Worm gearboxes for solar tracking systems
    2nd Quarter 2019, Bearing Man Group T/A BMG, Electrical switching & drive systems & components
    BMG has extended the supply of Varvel gearboxes and variators for small and medium power applications to include customised worm gearboxes for installation in photovoltaic (PV) solar tracking systems.
  • Energy-saving drives and motors
    2nd Quarter 2019, Electrical switching & drive systems & components
    With the implementation of variable speed and the optimisation of mechanical speed reduction efficiencies, maximum saving of electricity consumption can be obtained in any power transmission system.
  • Beacon lights of the modern age
    2nd Quarter 2019, Horne Technologies, This Week's Editor's Pick, Electrical switching & drive systems & components
    Anyone who takes a look inside a lighthouse along the French coast has a good chance of experiencing drive technology from Faulhaber.
  • Creating tomorrow’s marine braking solutions
    2nd Quarter 2019, This Week's Editor's Pick, Electrical switching & drive systems & components
    Stromag has designed and manufactured marine braking systems for decades, and the company’s products are installed on vessels operating across the globe.
  • Four questions to ask before choosing a drivetrain for heavy industries
    2nd Quarter 2019, Electrical switching & drive systems & components
    When it comes to performance and durability, not all power and motion transmission solutions are created equal.
  • Innovation and intelligence for the smart factory
    2nd Quarter 2019, Omron Electronics, This Week's Editor's Pick, Electrical switching & drive systems & components
    Thanks to increased processing power and the availability of increasing volumes of data (sensitisation of the industry), the discussion about artificial intelligence (AI) in the mechanical engineering sector is gaining momentum.

Technews Publishing (Pty) Ltd
1st Floor, Stabilitas House
265 Kent Ave, Randburg, 2194
South Africa
Publications by Technews
Dataweek Electronics & Communications Technology
Electronics Buyers’ Guide (EBG)

Hi-Tech Security Solutions
Hi-Tech Security Business Directory

Motion Control in Southern Africa
Motion Control Buyers’ Guide (MCBG)

South African Instrumentation & Control
South African Instrumentation & Control Buyers’ Guide (IBG)
Terms & conditions of use, including privacy policy
PAIA Manual


    classic | mobile

Copyright © Technews Publishing (Pty) Ltd. All rights reserved.