Direct-Fired Thermal Oxidizer PLC Migration
Flexible packaging facility | Midwest United States | Emergency legacy Siemens S5 replacement with new BMS logic, HMI visibility, and compliance data capture.
Challenge
A flexible packaging printer in the Midwest was operating a direct-fired thermal oxidizer on a Siemens S5-115U platform that had been obsolete for more than a decade. When a power supply module failed, no suitable replacement could be sourced in time, and the facility was pushed into manual bypass mode while it searched for emergency controls support.
The operational risk went well beyond downtime. The plant’s Title V permit depended on continuous parameter monitoring, but the legacy system could not provide the data quality, alarm management, or historian integration needed for defensible records. The migration had to restore operation quickly, rebuild the burner management logic to current expectations, and give the plant a workable compliance reporting path without extending the outage.
Solution
VIR Automation mobilized within 48 hours to assess the legacy controls, confirm field device status, and define an accelerated migration plan. The retrofit replaced the S5-115U with a Siemens S7-1500 platform, rebuilt the sequence in TIA Portal, and incorporated NFPA 86-aligned burner management logic with safety relay integration for purge, permissives, flame supervision, and shutdown handling.
A Siemens Comfort Panel TP1200 HMI was added to improve operator response with ISA-18.2-style alarm organization, real-time process visibility, and guided fault acknowledgement. VIR also integrated continuous data logging for Title V CAM parameters, added temperature, pressure, and flow trending, and tied the ID fan VFD into a tuned PID strategy to stabilize draft while reducing electrical demand. The project closed with as-built documentation, startup support, and secure VPN access for remote diagnostics.
S5 to S7-1500 Migration
Emergency controller replacement with updated architecture, I/O mapping, and validated operating sequence.
BMS Modernization
New burner management logic and safety relay interface built around purge, ignition, flame proving, and trip response.
CAM Data Logging
Continuous tracking of required temperatures, pressures, flows, alarms, and operating states for compliance support.
ID Fan VFD Optimization
PID tuning and VFD integration improved draft stability while reducing electrical consumption.
Results
Rapid Recovery
The oxidizer was restored from bypass mode to normal operation in 12 days including engineering, fabrication, and commissioning.
Modernized BMS
The facility achieved full NFPA 86-aligned burner management logic for the first time on this asset.
Lower Fan Energy Use
ID fan VFD optimization reduced electrical consumption by approximately 18%.
Less Manual Reporting
Automated CAM parameter reporting removed more than 10 hours per month of manual logging work.
Technical Details
Siemens S7-1500 (1515-2 PN)
Siemens Comfort Panel TP1200
Siemens F-CPU with safety relay interface
48 digital I/O, 16 analog I/O
PROFINET
Siemens S5-115U
Related Services & Resources
This project connects closely to PLC programming, controls integration, commissioning & startup, and the broader case studies library.
PLC Programming
Platform migrations, sequence redevelopment, and startup support for oxidizer controls.
PLC Migration Guide
Planning guidance for moving off legacy PLC-5, SLC-500, and similar obsolete platforms.
NFPA 86 BMS Guide
Review common burner management requirements that shape oxidizer retrofit scope.
Free Commissioning PDF
Download the thermal oxidizer commissioning prep guide for retrofit planning and startup readiness.