Automation of Water Resource Recovery Facilities. Water Environment Federation

Site Integration Test (SIT).

3.1.6.5 Operator Interface Terminals and Operator Workstations

      Before the control system is staged and tested, OIT and operator workstation (OWS) displays must be configured as agreed upon (e.g., layout, passwords, and security), loaded onto the process control system server or stand-alone personal computer OIT, and tested. The control system’s OIT and OWS software should include the following:

      • Graphic symbols of the project’s process schematics, as shown on the contract P&IDs;

      • Graphic symbols of each field panel, as shown on the contract P&IDs; and

      • Graphic symbols of each field instrument, as shown on the contract P&IDs.

      During OIT and OWS testing, testers should

      • Review the main menu display contents and demonstrate how an operator will navigate within the overall display structure (the main menu display should provide a list of all available displays and a link to the various subsystem displays);

      • Demonstrate which displays are assigned to which keys on the workstation keyboard;

      • Confirm that all graphic display components (e.g., layout, symbols, and color scheme) are correct;

      • Prove that standard-alarm management displays (e.g., current alarm display and alarm history) function as intended; and

      • Show that each specified type of report can be generated and printed.

3.2 Construction Management

      Once the new control system is delivered to the site, the construction management team is responsible for installation, field tests, and other related activities. Manufacturers may need to certify the installation of specialized equipment (e.g., process analyzers). They can also test equipment, provide startup assistance, and train users.

      Intelligent field instruments and asset-management software can simplify commissioning activities such as system configuration and loop checkout. Intelligent field devices or instruments generate equipment status and diagnostic information that are gathered by asset-management software at a central site (e.g., a control room or maintenance shop) where the installation team can review it all. This approach is more efficient than the traditional method of having team members travel throughout the facility to test each device individually (Johnson and Bailey, 2000; Raven, 2001).

3.2.1 Installation Inspections

      Every instrument, control panel, field device, and control valve should be inspected by site inspectors to ensure that they have been installed correctly in accordance with approved installation details. In addition, instrument and other manufacturers should be on-site to certify that their equipment has been installed correctly. Manufacturer-authorized representatives should then certify installation in writing by providing an installation certificate. This will ensure that equipment or device malfunctions discovered during testing are not caused by improper installation. It is also a good idea to involve the owner or facility personnel at this stage so that they can identify any concerns they have with installation.

3.2.2 Instrument Calibrations

      As with installation verifications, all instrument calibrations should be field-verified whenever possible. Most devices should be factory-calibrated; field verification will ensure that device calibrations are per factory settings. Some instruments will need to be calibrated in the field. As an example, magnetic flow meters are subject to wet calibration under controlled factory environments; however, a thorough check of magnetic flow meter parameters should be conducted on-site using built-in tools at the transmitter or specialized test devices furnished by the magnetic-flow supplier. In all instances, calibration documentation (e.g., certificates) should be produced by the contractor or system integrator and these should be witnessed and signed off on by site inspectors.

3.2.3 Field Tests

      Field tests (site acceptance tests) as described further in this manual should be conducted after the new control system has been installed and wired and each instrument has been verified and calibrated. The ISA publishes a useful guide to testing requirements that includes site acceptance testing (SAT), system integration testing (SIT), and factory acceptance testing of automation systems in the process industry (ISA, 2011).

3.2.4 Wiring Tests

      Before scheduling I&C testing (e.g., loop testing) of a control system, a thorough test of field wiring should be performed by the installing electrician. This test should include complete wire insulation testing (“meggering”) and continuity testing. It should also comprise testing for the presence of grounds, shorts, and correct terminations at the designated devices and panels in accordance with approved interconnecting wiring diagrams.

      Testing for fiber cables should also be performed using an optical loss test set (OLTS). The OLTS consists of a light source and an optical power meter. The main function of this equipment is to measure the optical power or loss. Testing should be conducted according to Telecommunications Industry Association (TIA) guidelines (TIA TSB-140; http://www.instrument.org). This document provides guidelines for the field-testing length loss, and polarity of a completed fiber optic link.

3.2.5 Loop Testing

      Loop testing confirms that each “control loop” in the system functions as designed. A control loop is a combination of one or more interconnected instruments that are arranged to measure or control a process variable (ISA-67.02.01-1999 and ANSI/ISA-5.1-1984).

      All loop testing should be overseen and approved by the site engineer. Resulting loop sign-off sheets should be kept as test records. Consideration should be given to combining loop testing with I/O testing, especially if the integrator is also the instrument supplier. This could represent a significant reduction in costs for a project.

3.2.6 Integrated System Testing

      After each control loop has been tested, the construction management team should test the entire control system, including signals to and from controlled field equipment (e.g., motors, sensors, transmitters, valves, and VSDs). Before the test begins, the system integrator should write up the entire test procedure and submit it to the design engineer for approval. It should include a list of items to be checked, such as a database listing grouped by I/O for each area of the WRRF. The database listing should include all wired I/O points, virtual (nonphysical) points, and derived points. Sorting the database I/O listing by process area helps make system checking easier.

      During the integrated systems test, the control system must operate for a specified period of time without failures. If the factory acceptance test was well executed and all control system equipment from the factory was tested properly, then the integrated systems test should only be limited by field wiring issues.

      The integrated system test should be overseen and approved by both the engineer and the owner. A log of all testing activities, with the initials of the system integrator, engineer, and owner next to each functioning item, should be kept as test records. The integrated system test is also referred to as SIT (ISA, 2011).

3.2.7 Commissioning and Final Acceptance

      Final acceptance is also referred to as SAT (see Automated Systems in the Process Industry—Factory Acceptance Test [FAT], Site Acceptance Test [SAT], and Site Integration Test [SIT] [ISA, 2011] for a comprehensive standard on the subject). The new control system should not be formally turned over to the owner until all startup and commissioning activities are complete. The contractor should also be required to meet the following two conditions