Читать книгу Automation of Water Resource Recovery Facilities - Water Environment Federation - Страница 93

When designing a control system for a WRRF, engineers must accommodate multiple vendor and equipment variations. Public works projects typically are awarded to the lowest bidder, who often chooses the least-expensive instruments that meet project specifications. As such, engineers must allow for such eventualities and adjust the design accordingly. For example, space must be allocated to accommodate differences in dimensions among various vendors’ equipment. Fortunately, wiring for most WRRF instrumentation has been standardized (e.g., 4- to 20-mA outputs, standard protocols [i.e., HART and Fieldbus]). Smart instruments incorporating wireless technologies and Ethernet communications should also be considered; these technologies are becoming more mainstream at industrial sites and may provide the solution to specific facility needs.