Modernization: Upgrading a BMS to a SIL3 PLC system

Modernizing an existing BMS to a Schneider Modicon 580 Safety PLC to be compliant with FM Global & CSA B149.3:20 standards.

Overview:

A client needed to upgrade their Burner Management System (BMS) to meet SIL3 safety standards and selected a PLC with a SIL3 rating. The hardware vendor sought InnoTech’s expertise, as they lacked the capability to handle the installation at the required safety rating. InnoTech provided panel design, PLC programming, HMI development, and commissioning support. Effective collaboration resolved I/O discrepancies and design issues, ensuring on-time delivery. The client’s BMS is now compliant, and the vendor gained a framework for future projects.

Situation:

A client’s Burner Management System (BMS) required an update to meet current industry standards, specifically compliance with FM Global and CSA standards (B149.3). They had a HAZOP  conducted, revealing that some of the process loops for the BMS required either a SIL2 or SIL3 (Safety Integrity Level) rated PLC system. As a result, the client chose a Schneider Modicon M580 Safety PLC and subsequently contracted a vendor for the hardware and installation.
There was a 3.5-month deadline to complete the project and install the system during a planned mid-September turnaround.

Risks:

The client needed to bring the BMS up to code to avoid legal ramifications and implement the hardware by the scheduled commissioning date to prevent unnecessary downtime. The vendor needed to implement the new one before the planned turnaround.

InnoTech selection:

However, the vendor did not have experience with installations for BMSs at a SIL3 rating (unfamiliar with the SIL rating calculations and the multiple I/O points associated with the PLC). They had no existing “Typicals”[1] to refer to for this, and with time running short, the vendor required assistance in designing and programming the system.

The vendor came to InnoTech, knowing that our team has trusted processes and procedures and expertise in programming safety systems and meeting SIL standards required for BMS. So, the vendor sub-contracted InnoTech to deliver tailored engineering solutions and bring the burner management system up to code.

Task and Scope:

The customer chose a Schneider Modicon M580 PLC for its high reliability, SIL3 safety rating, and timely delivery. InnoTech provided engineering solutions that included:

1. BMS control panel design

• • PLC Panel layout drawing
  • PLC Panel bill of materials
  • PLC Panel Schematics

2. BMS configuration

• • Functional Design Specification – PLC & HMI
  • Boolean Logic Diagrams
  • Data Transfer List
  • Alarm List
  • Programmable Logic Controller (PLC) Programming – M580 Safety PLC
  • Local Human Machine Interface (HMI) Programming

3. Factory Acceptance Test plan development
4. FAT Acceptance Test
5. Commissioning and site support.

Actions taken:

The InnoTech team leveraged the client’s standard BMS design and our experience with SIL3 rated PLC systems to complete the project.

Analysis and Comparison

The InnoTech team thoroughly analyzed the client’s initial design against one of their pre-existing Typicals. During the process, discrepancies in I/O points were identified, which prompted in-depth discussions to ensure that all necessary I/O were included, and all the unnecessary I/O were removed.

Panel Design Revision

The existing Typical designs did not account for SIS hardware, so the panel design was rearranged in order to incorporate this. Revisions were reviewed by the client to finalize the design.

Effective Communication

Continuous communication with the client’s project team significantly facilitated quick decision-making and periodic reviews, ensuring that the client remained up-to-speed for the Site Acceptance Test (SAT) and commissioning. Furthermore, collaborating closely with the customer allowed both organizations to capitalize on their combined expertise, which, in turn, helped streamline the engineering process. Ultimately, this collaboration was a significant factor to the success of this project.

HMI Programming

The team programmed the Human-Machine Interface (HMI) using RedLion, creating the display and connections to ModBus units from scratch. Throughout the process, they ensured that it met client requirements by conducting collaborative reviews, which further refined the system to align with the client’s needs.

Procurement

The InnoTech team quickly mobilized to finalize the hardware requirements and placed the order for the safety system. Fortunately, thanks to the PLC vendor, the hardware was delivered in just 6 weeks, providing enough time to fabricate the PLC cabinet and complete the FAT. As a result, the team was able to maintain the project schedule and stay on track for successful delivery.

Challenges:

Timeline

Implementing a SIL3 system was decided late into the design process, which created a great deal of engineering rework. Consequently, InnoTech and the vendor had only 3.5 months to complete the project for the planned shutdown in September.

Parallel engineering:

The mechanical and process work by the client was being executed in parallel to the engineering design. As a result, this led to a significant amount of rework, including obtaining stamped inputs and filling in the gaps necessary to complete the design.

Custom design needs

There was misalignment with the provided Typical and the proposed design, which required much customization for it to work with the end customer’s facility.

Results from the BMS upgrade:

The solution was successfully delivered in time for commissioning. The client’s BMS is now up to the required safety standard and the vendor now possesses a comprehensive Typical for implementing a BMS with an SIS system that includes:

• Panel layout
• Lamacoid schedule
• Bill of Materials (BOM)
• Wiring for power and I/O
• Power supply alarms
• Module and special drawings

The new framework not only enables our client to implement similar systems efficiently and easily, but it also enhances their ability and confidence to manage SIS BMS projects more effectively.

Discussion Question:

What strategies can engineering teams implement to effectively manage parallel workflows and minimize rework in complex projects like the implementation of a Burner Management System?

[1] A Typical is the standard specifications for design, materials, and processes that the client follows for products based on similar applications.