December, 1998

'Twas the night after Christmas and all through the facility, not an operator of stirring or mixing ability. The PLCs were hung in the enclosure with care, in hopes that Superior Controls soon would be there.

On December 26 at 6:00 P.M., the night after Christmas, 12 Superior Controls engineers and technicians began working through the night replacing an obsolete chemical control system. The project, itself, was fairly typical. Superior Controls was responsible for providing and programming two programmable logic controller (PLC) based systems with approximately 600 input and output signals. All field wiring including the detaching of the old system and rewiring of the new system was implemented by Superior Controls. Not so unusual . . . except all the field wiring and start-up tasks had to take place within 48 hours.

This Fortune 500, New England-based, chemical company had a problem. Their solvent recovery and industrial waste water treatment system was being controlled by a 12-year-old PLC system. Obsolescence and trouble obtaining spare parts made it essential that the PLC system be replaced. However, four major manufacturing buildings were dependent upon this treatment system 24-hours a day, so the only time this continuous process could be interrupted was during a 48-hour window during Christmas break. In addition, the PLC system for a nearby Regenerative Thermal Oxidizer (RETOX) had to be replaced during this same weekend.

Patty Ascanio, lead project engineer, noted, "It was absolutely critical that both systems be back up and running in the allocated time. If the system is not, the entire site would be shut down."

Although large and complex, the industrial waste water and RETOX systems were only two of the 11 networking PLC systems Superior Controls had implemented at this facility during recent years. With 11 Modicon PLCs and six FIX-based SCADA Nodes, the entire system controls and monitors more than 3,000 field points.

Before the big weekend, Superior Controls and Beckwood Services, constructed several panel inserts containing the PLCs, I/O modules, and terminal blocks. These would fit neatly into the old control panels after the old control equipment was removed. The control programs were tested prior to going on-site. The RETOX system, because of its critical nature, was tested and simulated several times. Numerous coordination meetings were held and contingency lists prepared.

Mark LaRoche, director of engineering noted that "Months of planning resulted in complete success. Groups of engineers and technicians worked around the clock in 12-hour shifts through the weekend. With great efforts both systems were rewired and back up and running in the allotted time." Applause to all associated with the project.