Project Background and Problem
A leading natural gas producer required a critical plant shutdown signal to be sent from their control system to a third-party downstream control system. This signal would notify the third- party facility of a supply disruption during an Emergency Shutdown (ESD) event, allowing them time to respond and maintain safe operations. Equinox Automation was engaged to engineer the required system modifications ahead of a planned plant shutdown when the design would be implemented.
Solution
Our engineering team conducted a detailed review of the existing system, including a site visit to assess panel layouts and existing connections. We gathered relevant documentation and developed a design that clearly mapped the cable connections between the client’s DCS and the downstream system. We identified available terminals, labelled all required connections to site standards, and used an interposing relay to electrically isolate the two systems—ensuring a fault in one would not impact the other. All design work was completed using software-based drawing tools, including updated termination and loop diagrams. The design underwent internal review and was certified to meet AS/NZS 3000 wiring rules and the Electricity (Safety) Regulations 2010. A comprehensive construction installation workpack was created to guide site execution, including safety considerations, installation steps, commissioning procedures, and all required electrical and instrument drawings.
Results
The solution enabled reliable signal transfer between the two facilities, improving safety and response times during unplanned shutdowns. The project was delivered on time, and the client commended the high-quality design and clear documentation, which simplified installation during a tight shutdown window. Equinox Automation delivered a cost-effective and fit-for-purpose design, leveraging existing infrastructure where possible and supporting efficient field execution.
Figure 1, 2 & 3: Legacy DCS and control cabinet wiring that requires detailed inspection during the site survey.
Figure 4: Inter-Facility Shutdown Signal Loop diagram
Figure 5: Detailed Instrument Design & Installation Work Pack