Water Well Journal

September 2015

Water Well Journal

Issue link: https://read.dmtmag.com/i/557876

Contents of this Issue


Page 41 of 71

H ere we are at the end of summer and a series of articles to provide you some fundamental facts you should really know about various water system components. Part 1 delved into the pump-related topics. Part 2 high- lighted the items you should always have at hand about the drivers (motors, engines) you use that run the pumps. Part 3, this final insert, will cover the control aspects. Of all three sections, this one has been the most difficult for me to prepare. How do I decide what you really need to know about a group of items that has exploded in use and versatility during our lifetimes? Not only has the technology involved with controls ex- panded exponentially during the past 40-some years, but what has really changed with pumps and motors over that same span? Sure, there have been technological, material, effi- ciency, and design improvements to pumps and motors. But compared with controls, the changes have been relatively minor. Since 1974, the year I began in the water well industry, the improvements to controls have expanded greatly. Not only have controls evolved from simple electro-mechanical relays and pneumatic timers, but every component now seems to revolve around the use of electronic components. Din-rails, programmable logic controllers (PLCs), and even computers (once relegated to use primarily on space-related projects like satellites) have now increased in use to fully operate many of our water and wastewater systems. What are controls? Controls, as far as this article and myself are concerned, are anything in the entire "three-link" system that either inter- face, protect, or provide the operational control between the pump (first link), the driver (second link), and water or any other fluid they mutually transfer (third link). The driver itself could be an electric motor, an internal combustion engine, or a turbine. It also includes the source of power used to provide a force to the driver—electricity, diesel fuel, gasoline, natural gas, propane, water for driving a turbine, or wind for turning a windmill. You can see from these descriptions controls virtually in- volve almost anything within a water system except for the pump or driver themselves. One of my engineering registrations is as a control systems engineer. As such, I have used this training and knowledge through the years for designing control systems for numerous water and wastewater systems and several industrial systems. I use a broad definition when describing controls, and that's how I think it should be. For the proper use of any con- trol in a system is to provide just enough supervisory control to operate or protect the system and its components—without providing any more control than necessary that could either hamper or interfere with the system. I tend to look at a control system as the previously indi- cated "three links" in a chain. That's because a chain derives its strength from each link contributing to the whole. However as you know, the more links you have in a single chain, the more likely one of them will eventually fail and disrupt the entire piece. Remember this fundamental tenet when you work with control systems: Always provide enough control to properly operate and protect the system, but knowing that having too much control can be just as bad as too little. So, let's begin the list of 10 things you should really know about controls. 1. Keep it simple I'm often bombarded by sales engineers or technicians who are convinced they represent the next best thing in control devices or systems. This can run the gamut from new and improved pressure switches up to the next generation of sophisticated PLCs. One of the basic reasons for this attitude is the relatively recent explosion of improved electronics, invariably in smaller and smaller sizes. This trend towards the never ending improvements in elec- tronic devices was actually developed way back in 1965 through a prediction referred to as Moore's Law. Developed by Gordon Moore, co-founder of Intel, his law stated the tran- sistors in an integrated circuit would double every two years for the foreseeable future. This prediction has largely come to pass over the years. For example, many cameras, stereos, television sets, radios, and other electronic devices from the 1970s and 1980s are now basically regarded as obsolete due to the cost and manufactur- ing advantages offered through the use of integrated circuits. ED BUTTS, PE, CPI ENGINEERING YOUR BUSINESS Every component now seems to revolve around the use of electronic components . Ten things all contractors should know. waterwelljournal.com 40 September 2015 WWJ

Articles in this issue

Links on this page

Archives of this issue

view archives of Water Well Journal - September 2015