Pima County Wastewater Treatment Plant – Corona De Tucson, AZ
In July of 2007 Pima County Wastewater Treatment Plant expanded by adding an Aeration System. This was a completely new process with new equipment and controls at the site.
EleMech Inc. provided the controls for this new system which included the control and integration of 20 motors total. This included (2) 0.5HP Clarifiers, (8) 10HP Motive Pumps, (7) 25HP Blowers, and (3) 3.7HP RAS Pumps. The control system used Allen-Bradley ControlLogix and Panelview Plus touch screen technology to operate on a closed loop PID control. The ControlLogix PLC was networked to the ABB ACS550 variable frequency drives via MODBUS RS485 communications. The control system also monitors instrumentation to automatically adjust the speed of the Blowers based on demand.
The touch screen displays Basin #1 & #2 each
with 3 dedicated blowers. Blower 4 is displayed
in the center allowing the facility to use it for
either Basin when necessary.
EleMech’s Project Manager, Aaron Squires traveled to the jobsite for startup on the system. The startup included verifying the field wiring and connections to the field devices, tuning the PID loops, instrumentation, and network communications, and providing system training to the facility operators. Frank Gall, the Facility’s Superintendent stated, “The training at startup was pretty straight forward and easy to understand.”