by Andrew Green
As technology progresses, packaged pump systems and their corresponding remote terminal units (RTUs) are becoming ever more economical. In fact, the benefits of utilizing a single type of RTU/controller to monitor and control remote pump stations continue to rise. However, there are a few questions that should be asked before determining to forego a custom controller in favor of a standardized unit.
1. Are all of my pumps the same?
Different pump manufacturers have different ways of manufacturing the control panels used for local control of their pumps. Some manufacturers outsource to panel shops, some send their panels with wireless connectivity to SCADA already built in, and others self-perform all of that electrical work. The point is that, unless your pumps are all from the same manufacturer, there could be a lot of work on both the hardware and software side to get your standard RTU to communicate with the different control panels. If you are in the position of a greenfield project and being able to determine everything for your entire system on the front end, proceed with your standard unit – by all means! But, more than likely, your system has several different brands of pumps (depending on the application) that you are interested in monitoring. Customizing your RTU by according to the pumps and control panels that are already existing alleviates some of that risk in additional cost. Let your existing equipment determine your RTU, not the other way around.
2. Will the units communicate with my existing SCADA system?
Existing SCADA software and bandwidth will determine the ease of integrating your RTUs with your SCADA system. Many of the standard packaged products come complete with their own brand of SCADA and communication protocols. It could be that the packaged RTUs being explored come complete with drivers for your existing software. That’s great news! But most of them will require the purchase of additional drivers (at a higher cost) in order to communicate with your existing system. Make sure that you are comfortable with the possibility of not being able to see everything in one place, if you don’t have a good answer to this question. Also, keep in mind that very few packaged RTUs will work both inside and outside of the plant. Most units are very adequate for one or the other, but not for both.
3. What is the ease of support service?
Ask yourself how much money you are really saving if your RTU can only be worked on by the manufacturer who is 1000+ miles away. Are replacement parts available at your local electrical distributor in the case that inclement weather knocks out one of your units? Is the expertise to work on the unit, which typically has proprietary elements, easily accessible or will you find yourself flying a service guy to your location as the only company in the country who can perform the service work? If support service is limited in supply, believe that it will be expensive.
The conclusion of the matter? The solution for monitoring and controlling your pumps needs to make sense to you and for your system. Custom-built solutions can be more expensive on the front end of the job. But they offer a myriad of benefits when compared to standardized solutions – especially if your system is not uniform across the board.