Electrical ­Control and Instrumentation ­system for the Lower Thukela Bulk Water Supply Scheme

Autotronix LTBWSS Project

Autotronix has designed, installed and commissioned the electrical and control
system that is in use at a large bulk potable water infrastructure project in
KwaZulu-Natal, known as the Lower Thukela Bulk Water Supply Scheme
(LTBWSS). The overall project was undertaken by Veolia Water, with Autotronix as its sub-contractor. As part of the project, the
plant supplies 55 Ml/day potable water to various towns within the iLembe District.
The scope of the Autotronix contract included the supply of all electrical equipment, control and visualisation products for a control
system that will automate the abstraction, treatment and distribution processes of the plant.
The plant abstracts water from the Thukela River through a low-lift pumpstation and, following pre-screening for the removal of
coarse grit (as well as aquatic life), diverts it to a water treatment process that includes filtration, flocculation, clarification,
disinfection and sludge dewatering.
Design description
Consultants Aurecon specified the initial technical documentation from which Autotronix developed the final designs in
cooperation with Aurecon, the Veolia Water technical team and the client, Umgeni Water.
Detailed design for the electrical section, including MV and LV, control and instrumentation, was undertaken by Autotronix, with
approvals by all participating stakeholders. Once approved, the MV switchgear, LV switchgear and automation equipment was
manufactured and assembled locally. All testing and factory acceptance testing was carried out in the local Durban facility prior to
installation at the plant.
The scada software is hosted on a system of servers, providing complete redundancy of both hardware and software and
incorporating the latest virtualisation technology. New graphics were developed using the Rockwell Automation FactoryTalk View
package to display plant status and facilitate easier control of the plant. Additional software includes FactoryTalk Historian, which
logs plant parameters and collects critical time-series data to provide a performance database that can be used for a range of
statistical and predictive functions.
An industrial fibre-optic Ethernet network was installed for the PLC and scada communications and the field instruments were
integrated into the Rockwell Automation Allen-Bradley ControlLogix PLCs via Ethernet network. Autotronix also supplied and
commissioned three 355-kW PowerFlex AC drives; Dynamix 1444 integrated condition monitoring modules; and E300 electronic
overload relays as part of the motor protection.
“Ground-breaking techniques were introduced, and new standards have been set with reusable objects that have been tried and
tested,” explains Autotronix’s Haroon Bassa. “The system has proven reliable and user friendly,”
The automation design of the plant has resulted in only a few staff required to operate the plant, clearly illustrating Autotronix’s
expertise in providing a quality control system to the end user.
For more information contact Autotronix, +27 31 705 0400, sales@autotronix.co.za, www.autotronix.co.za