As part of the Capenhurst site refurbishment and upgrade program the client required an assessment of all EC&I systems across all production facilities in buildings E23, E22 and A3.

The assessment included functionality; plant condition; obsolescence and compliance with current industry standards.

Plant records had been centralised from various legacy systems, but did not always faithfully reflect the actual plant and were often in non-maintainable format. A verification exercise was undertaken to align the records with the “As-Built” plant status and ensure the records were in a suitable electronic format to support future operations, maintenance and decommissioning.

Services Provided

Using an agreed methodology the collated information for each plant EC&I system and subsystems, was audited against the actual physical layout and construction. Any deviations between available information and plant configuration were noted for rectification. Baseline information included:

  • Block Cable Diagrams (BCD);
  • Single Line Diagrams (SLD);
  • Connection and Loop diagrams;
  • Schematics;
  • Piping & Instrument Diagrams (P&ID);
  • General Arrangements (GA).

The following systems were surveyed and audited:

  • Low Voltage Power distribution (up to 415V);
  • Temperature loops;
  • Pressure loops;
  • Flow loops;
  • Weighing systems;
  • Safety related control systems (SRS);
  • Seismic monitoring systems;
  • PLC control & monitoring /SCADA interface;
  • Emergency Lighting control.

As part of the survey process all of the system components parameters were checked and verified along with all wiring, terminations and identification methods being employed.

Discrepancies between plant and drawing were noted and “red line” drawings generated with a concise condition appraisal report. An auditable document control system was used to enable an accurate and comprehensive library of “As-built” documentation to be compiled.

The survey team also functioned as a resource for both the principal contractor and end client engineering design departments by providing detailed “on site” information and data relative to the projects they were undertaking. Also by the fact that the team were present in the production areas for considerable periods of time they were able to advise the client maintenance and operations departments of any issues that were observed and that it was felt required their attention.


The client emphasised that the survey and inspection work must have no impact on the operational and production effectiveness of the plants. A major benefit to the client was that Tenet provided Electrically Nominated personnel so that the intrusive and no-intrusive works could be undertaken without the need to isolate equipment.

The original drawings procured for the purposes of the survey were found in some instances to be up to nearly 40 years old and had been produced over the years by a variety of companies who had employed various standards of drafting them, but due to Tenets experience and familiarity of the Capenhurst site and experience within the survey team this issue did not present a problem.

For two years Tenets survey team carried out the live survey and inspection works across the plants without incident by strict adherence to the site rules, regulations, working instructions and by close cooperation with the Plant Operations department.

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Due to Tenets previous experience of working on the Capenhurst site and by adhering to client standards, the Tenet survey team were able to quickly understand project requirements and produce deliverables needed to form a detailed and accurate survey of the EC&I systems and equipment employed across the prescribed production plants.

The information and data collated during the contract as to the actual “As Built” status of these systems and the subsequent revision and updating of all the drawings associated with them will enable a detailed and comprehensive library of information to be formulated within the sites central database that can be viewed with confidence that it presents an accurate presentation of the EC&I systems current status.

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