Water Online

MAR 2017

Water Innovations gives Water and Wastewater Engineers and end-users a venue to find project solutions and source valuable product information. We aim to educate the engineering and operations community on important issues and trends.

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ripple effects will be, and how to mitigate or remove the hazards. It is always best to engineer the hazards out, but that can result in too much automation, as described above. If a failure will not cause an injury, environmental compliance issue, or damage to equipment, then it can be alarmed, but it should not cause a shutdown. Shutdowns should be used only for imminent threats to safety, environment, or equipment. Notice that I left out "process." When commissioning, you won't be hitting your process requirements until you are well underway, so don't let that shut you down. If it can cause any of those three critical events, will it cause them immediately or is there a buffer time? Take, for example, flow to a pump. How long can the pump safely run in a low flow before damage occurs? How high is the maximum outlet pressure able to reach, and for how long? How full can your tank get before it is truly overflowing? How empty before vortexing your pump? The answers to these questions will determine the setpoints and variables on your alarms for commissioning. Conclusion Automation is great, but we have to use it wisely. The operator must be the master of the system. When we write programs we should have a commissioning mode in the operation. During commissioning, there are far more hands on deck than in normal operation. Automation should be programmed to account for this. Also, most of the equipment will not be operating in its optimal range, which needs to be accounted for as well. In this stage of operation your process will not be optimal either. Do not expect an effluent that matches your process requirement, and adjust your automation and alarms to allow for staggering deviations. The best-engineered system will start like an old tractor the first few times you run it. It will shake and rattle and blow smoke. That is why we commission and don't simply plug and play with large, complex systems. So adjust your automation, sensors, controls, and shutdown keys to match your commissioning conditions, and allow your people to be the brains of the operation. Your operators will love you for it. n wateronline.com n Water Innovations 23 AUTOMATION Paul Brake is a mechanical engineer with three decades of indus- trial experience. He is currently engineering manager at RJ Oil Inc. Environmental Solutions, in Acheson, Alberta, designing and building remediation equipment. About The Author Automation provides efficiency but doesn't promise a smooth setup. If a failure will not cause an injury, environmental compliance issue, or damage to equipment, then it can be alarmed, but it should not cause a shutdown.

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