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Are Reliability and Distance Interlinked?



Photo courtesy of Texas DOT.

Frost and Sullivan created a survey about water and wastewater end users' purchasing criteria. In our market, an end user is the water and wastewater facility. In the survey, Frost and Sullivan identified reliability as the first concern.

Of course, reliability takes many forms, ranging from part reliability to the distance from the facility to the place a replacement part can be purchased.

Let’s look at a real example: I was starting a facility in the California’s central valley, and the PLC that I was working with had a problem with its processor. I was several thousands of miles from home, and I had to get this going. In this case, I got lucky: The closest distributor was about 30 minutes away in Modesto.

However, I realized later that if I had used another popular PLC platform, the nearest distributor would have been more than two hours away in San Francisco. This got me thinking: If I, as an original equipment manufacturer’s start up-person, could be impacted by distance, then what was the operator or facility maintenance guy facing?

The answer is rather scary. In August 2004, EPA provided a report to congress on CSO and SSO impacts. It named Mechanical and Power failures as the No. 3 leading cause of SSO failures at 11 percent (there was not a similar breakdown of CSO events). Let’s face it, pump stations are all very similar in how they work, just in different configurations. They are used for SSOs, CSOs, or water distribution; they all use motor starters, or VFDs; and they all have valves and pipes. Therefore, similar findings to the SSO situation must exist for all areas of pumping. Actually, mechanical and power failures may be more important criteria since the leading two causes, blockages and wet weather I/I, are not found in water distribution.

Nevertheless, if a pump station is down and you don’t have the proper valve, relay, or whatever, you could be in a world of hurt. How do you stop water flow when the part is 2.5 hours away one way by car? Not a good situation.

My experience does not allow me to comment on the distribution policies of equipment such as valve and instruments, but I can comment on the electrical aspects of the facilities. Some electrical suppliers are mostly focused on original equipment manufacturers; thus, they will have distribution centers in these areas. Some may have a broader focus but only have parts available in some areas. And then some may allow all of their parts to be sold everywhere but may not have technical support at all locations. Some suppliers are so small that they cannot provide a wide distribution network. So how do you determine which one? That is tough.

My advice is to be proactive during the design phase of your system. Find out what the proposed devices are, then go onto their Web sites and see where the nearest distributor is. Once you find out, ask yourself what the worst case scenario would be in order for you to drive that distance. Of course, the obvious question is what the distance should be. If you are in the sparsely-populated Southwest states, where distance is large but traffic is light, a 100-mile distance may be O.K. However, in the densely populated regions of the Northeast, 30 miles may be too far.

So what are your horror stories? Has distance proven to be a barrier or a bad situation made worse? Speak up!!

Posted by Grant Van Hemert, P.E., Schneider Electric Water Wastewater Competency Center on Mar 17, 2010

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