Processing, August 2019

The SI must place an early focus on reviewing submittals for the electrical OEM equipment and ensuring proper connections are available monitoring generation and distribution equipment and more rarely automation of these items However these systems may have significant controls and interlocking systems in place when received at the site with verification of proper operation required usually by the OEM The SI is far more likely to get involved with automating motor control centers and variable frequency drives as these operate process motors Furthermore this equipment and the uninterruptible power systems are often intelligent devices sometimes with onboard controls and network communications Therefore the SI must place an early focus on reviewing submittals for the electrical OEM equipment and ensuring proper connections are available For example a variable frequency drive may support the Modbus TCP protocol so the SI must ensure this protocol can be received and recognized by the main control system The SI may also need to send personnel in advance of commissioning and startup to work directly with electrical OEM personnel and installers to confirm the installation is coordinated with the SI automation detailed design Power distribution design is usually straightforward but the scope can become less clear for automation For instance basic motor automation may involve interrelated detailed design equipment sensors and controls provided by a process equipment vendor the electrical contractor and the SI The SI has the specialized knowledge to evaluate all these items and it is best positioned to identify and solve any gaps and overlaps Moving into detailed I O checkout and commissioning of the electrical OEM equipment with the SIs main automation system digital network interfaces to intelligent power devices must be tested Not only must basic signals be scaled properly but intelligent devices have many configuration settings and modes of operation that also must be carefully selected and proven to ensure proper application Just as I O signals are documented on checkout sheets the electrical OEM equipment configurations must be similarly documented Integration of process skids with the main automation system poses many of the same challenges as those found with electrical OEM equipment Integrating process skids Process skids found in water wastewater plants take many forms Figure 4 Some are smaller and selfcontained for shipment while others must be broken down and assembled on site Many come with complete onboard controls while others may be procured as bare equipment to be automated in the field Some are utility and support systems while others perform a key process role Here is a sampling of typical water wastewater process skid types Filtering Solids handling Reverse osmosis units Membrane bioreactors Ozone generators Ultraviolet systems On site chemical production Chemical injection Odor control Fire suppression systems Engine drives Blower packages Electrical OEM equipment as discussed in the previous section may involve some complications but is mostly evaluated for basic functionality such as on off open close start stop and run at a commanded speed Process skids however are more likely to have extensive automation requirements each of which affect overall performance This includes sequencing for events like backwashes cycling of equipment like ultraviolet systems based on demand timing of trains within a unit tuning of continuous regulatory control such as for chemical injection and other process operations When process skids arrive with their own control package there may be a simple enable disable interface exposed to the main automation system via a hardwired connection But even in this case a skid may also require operational parameters to be determined set and tested Therefore just as when electrical equipment is commissioned and started up the process skid vendors must be present and involved in the process because they are the specialists on how to operate their own equipment 92nd Annual Water Environment Federation Technical Exhibition Conference McCormick Place Chicago Illinois Conference Sep 21 25 2019 Exhibition Sep 23 25 2019 44 Processing AUGUST 2019 JOIN US IN CHICAGO REGISTER TODAY www WEFTEC org WEFTEC19