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Disclaimer:
The content in this paper is loosely based on experiences, and have been embellished to bring out the salient points
against the objectives of this paper.
The new facilities were designed and engineered by an Engineering Procurement Contractor and
installed as per the design. This included quality control and checks at various stages, including FAT, and
commissioning before handing over to site for operations.
What is missing?
Two years later another Greenfield/Brownfield project was to change out the existing ESD logic system
with a newer ESD logic system, including expanded for additional processes.
During the changeover of the ESD logic system a requirement was to review and check out all interfaces,
such that a smooth and uneventful change-over could be implemented without shutting down the
process. The system being energise to trip the outputs (ESD valves etc.), and via two separate routes,
enabled the project to plan changing over one channel at a time. There would be a limited period when
the ESD system would have only one channel to trip the ESD valves etc., hence the rigor required in the
execution planning and on validating output actions.
During the development works for the change-over method the investigation into existing functionality
it was identified that some ESD functions would never have worked, as they had field wiring into the
termination cabinet but no internal wiring to the ESD system.
Oops what went wrong with first project?
All Greenfield functions had been tested, including FATs, and proven to work from the new cabinets and
new equipment.
It appears that the ESD functions were not tested from the existing ESD system. An obvious statement
based on what was found.
IEC 61511 Part 1: 14 SIS Installation and Commissioning
14.1 Objectives
14.1.1 The objectives of the requirements of this clause are to
• Install the safety instrumented system according to the specifications and drawings;
• Commission the safety instrumented system so that it is ready for final system validation.
• etc.
14.2.3 The safety instrumented system shall be commissioned in accordance with planning in
preparation for the final system validation. Commissioning activities shall include, but not be limited to,
confirmation of the following:
• Earthing (grounding) has been properly connected;
• Energy sources have been properly connected and are operational;
• Transportation stops and packing materials have been removed;
• No physical damage is present;
• All instruments have been properly calibrated;