The client had two active waste water treatment facilities running on aging Allen-Bradley SLC-500 PLCs and Wonderware InTouch. Operational requirements made it impossible to shut these plants down so upgrades had to be performed without interrupting plant operation. Documentation did not exist for many of the existing control panels, and the client had no faith in the drawings that they had. Communication was a challenge as well with two systems integrators, an electrical contractor, a mechanical contractor, the owner, and multiple suppliers involved in the project.
All panels were meticulously field documented wire-by-wire including all field wiring out to the instruments. New drawings were developed for each panel incorporating the upgraded controllers. Cutovers to new controllers were staged one at a time and performed at night when inflow to the plant was at a minimum. I/O cards were pre-wired in our shop to reduce on-site time even further. Each cutover was performed in a single night. Converted, pre-tested PLC code was loaded by the second integrator, and I/O checkout was jointly performed in the same night. Communication between all parties was handled in a weekly meeting to keep the project on track, and when required, more frequent meetings kept the project running smoothly.
Benefits Received by Client:
The owner successfully upgraded the automation in two Waste Water Treatment Facilities to modern controllers that will see them through the next 20 years. The upgrade was performed with no interruption to either facility, and the project finished on time. The ten upgraded panels and one new remote I/O panel provided are accurately documented which will be a huge benefit to maintenance and operations moving forward.