Eagle Farm Pump Station PLC Upgrade

Client: Queensland Urban Utilities

Technology: Siemens S7-400/300, Siemens network switches

Eagle Farm Pump Station is Brisbane’s largest sewage pumping station, transporting around 65% of Brisbane’s sewage to Luggage Point Water Reclamation Plant for treatment.

The site consists of two pump stations pumping from individual wet wells. The first station handles dry weather flows, and comprises three 2000kW pumps with VVVF drives operating in duty/follow/ standby configuration into a high-pressure steel rising main. The second station is run under wet weather flow conditions and includes two 1750kW pumps which pump together into a concrete rising main. Combined the two pump stations can pump up to 8000l/s to Luggage Point.

Witthoft Engineering, in cooperation with Cardno and Wagtec, provided the full electrical and control system detailed design for a project to replace the aging GE 90/70 PLCs at Eagle Farm Pump Station. The existing configuration had two supervisory PLCs in a redundant pair arrangement controlling five PLCs (one for each pump) and 34 remote IO drops across seven individual GE serial networks

These were replaced by a pair of Siemens S7-400H PLCs and individual S7-300 PLCs for the five pumps, as well as a further 27 S7-300 remote IO drops, connected via a new Ethernet ring network.

The first step in the design was to reverse engineer current site functionality into an as-built functional specification. From here a number of workshops were held with QUU stakeholders to rationalise and enhance functionality as required to create the functional specification for the new system.

The design included:

• PLC and SCADA Functional Specification
• Network Diagrams
• Electrical Schematic and Termination Diagrams
• Physical IO Lists
• Flow Control and Changeover Strategy

Witthoft Engineering also developed the tender package for the project’s implementation phase, including hardware installation, PLC and SCADA software development, and commissioning.