Overnight Success – A SLC to CompactLogix Story

Sometimes our customers provide us with unique challenges. The truth? We thoroughly enjoy these challenges that require us to think creatively and out of the box. In this case, a PLC modernization with a tight window so that sewage literally didn’t overflow into the streets.

For those that aren’t aware, usually, a PLC conversion requires several hours of replacing hardwire, re-terminating each IO point in multiple locations, doing point to point continuity checks to verify wiring is correct. Even after the hardware and wiring are confirmed, more time is required to do software checkout of the new PLC.

As found control plan with SLC 500 equipment

This entire process is typically complicated enough that in many cases it makes more sense to build a completely new back panel with pre-mounted hardware. This reduces some complexity by literally ripping out the entire back panel, lifting in a new one, and re-terminating the field wires only. However, this effort can also take much time, extra equipment, and costs much more for material costs.

Challenged with cost and significant time constraints to minimize downtime, Convergence worked with our partners at Rockwell Automation and Rexel on the first commercially released 1492 I/O Wiring and Conversion System for SLC 500 to CompactLogix 5380. Even before the product was fully released, the team worked together to devise an upgrade path and strategy utilizing the customization features of the wiring kits to suit the unique IO card combination utilized at the facility.

1492 IO Wiring and Conversion System by Rockwell – Just released!

This solution allowed for the rapid removal of the existing SLC 5/05 without disturbing any field terminations – including the terminations to the SLC IO cards themselves.

After safely de-energizing the control panel, the team first removed the IO card wiring Removable Terminal Blocks (RTBs) from the existing SLC Cards. Once removed, the RTBs were able to be set aside while the SLC chassis itself was removed from the panel.

Back Panel after removal of SLC 500, hanging RTBs with field terminations

Utilizing the same pre-drilled holes for the SLC mounting in the back panel, Convergence was able to mount the metal housing for the new chassis directly to the back panel. By using the same pre-drilled holes, additional risk of metal shavings falling into existing electronics was completely erased. Once secured, the SLC wiring terminal RTBs were directly attached to the new wiring adapters. From there, the IO connector cables were plugged into the SLC terminals, then swung up to the top of the mounting chassis where the new DIN rail mounted 5069 CompactLogix was already mounted.

Mounting kit with SLC RTBs re-terminated, wiring conversion hanging below

The cable was simply plugged-in to the CompactLogix IO cards – and done. A complete PLC modernization, without ever touching the field or marshaling termination points; all done in under 60 minutes.

CompactLogix secured to exterior conversion chassis by din rail. Conversion wiring hanging below.

Because the PLC hardware replacement went so quickly, the team had more than enough time before their hard deadline to go the extra mile and clean up the panel further.

Completed CompactLogix Conversion

This included re-wiring the power distribution to simplify it’s management and operation, evaluating obsolete wiring and points, cleaning up the networking, and more. After the panel was cleaned up, the software checkout and commissioning began. Having completed the logic conversion in advance, the team had additional time to review the existing logic to optimize the programming enhancing the PID control of the pumps, level point settings, and lead/lag cycling.

All said, the conversion was done overnight during low flow periods with great success. Even better? No call out or issues since the installation. Done right, the first time.

SLC Migration? SLC Modernization? HMI Upgrade or SCADA Integration? Contact Convergence today and get a free consultation on your project and let’s discuss how we can make your project be an overnight success too!