electricity
It has always bothered me: Why do we take devices that draw electrical current and install them in aquatic environments where humans get in the water? Even if precautions are taken, isn’t this risky business? To be sure, suppliers have come up with all sorts of measures designed to protect bathers from any potential hazard, and I have nothing but praise for the ingenuity they’ve displayed in surrounding their products with safeguards that minimize concern. But based on my own observations and experience, I must say that
As I see it, successful landscape lighting is a two-part process: First, the designer applies aesthetic principles that create the art, then he or she supports that artistic vision with scientific and technological savvy. One without the other doesn’t work: You can’t effectively practice the art until you’ve mastered the science. In my 17 years as a lighting designer, I’ve encountered lots of professionals who have the artistic part of the equation down pat but fall well short when it comes to working with electricity. The plain fact is, you can use the best fixtures in the world and understand the aesthetic issues like the back of your hand, but if you can’t consistently deliver power to those fixtures at correct, reliable voltages, the overall system will not perform properly and has the potential to become a maintenance nightmare. There’s no way a single article can bring anyone up to speed with all of the issues involved in the science lighting. Instead, my intention here is to introduce watershapers to a basic, commonsense approach to laying out low-voltage, halogen lighting systems, the goal being to enable you to converse intelligently and persuasively with lighting designers in the interest of helping
Each year, the National Spa & Pool Institute offers special programs in conjunction with its International Expo. Most years, these programs include tours of local places of interest, such as notable museums, historical sites, outstanding examples of local architecture and the like. With the Expo in Las Vegas last December, NSPI took advantage of the location and included a tour of Hoover Dam and Lake Mead, a scant 30 miles from the glitz and glitter of The Strip. More than100
Last month we covered the "hows" of grounding pretty well. Using the definitions from the National Electrical Code (NEC) for guidance, we saw that in order to be considered effectively grounded, the non-current-carrying metal parts of all equipment associated with a watershape must be connected to the system grounding bus at the electrical service panel. This is accomplished by installing a green-colored (or green with a yellow stripe), minimum No. 12 AWG insulated copper conductor between the equipment's grounding terminal and the system grounding bus. This conductor is
Through the years, the #1 question asked of me at seminars and trade shows has been: "What's the difference between bonding and grounding?" I have wanted to do an answering article far some time, but I was concerned that its length would require it to be split into two pieces and that the every-other-month format of WaterShapes might make it difficult to maintain continuity of thought over a two-month span. I was pleased when our editor informed me that we would be going monthly for a while. I figured I'd strike now, while the fingers are nimble and the magazine issues more
During our last session, we explored the water-flow/electric-current-flow analogy and summed it up in a few sentences that are worth repeating: • Water: The pressure created by the pump forces water to flow through the pipes and valves, overcoming the friction losses of the system. Higher pressure provides for more gallons per minute. • Electricity: The voltage created by the battery forces electrons to flow through the wires and switches, overcoming the ohmic resistance of the circuit. Higher voltage provides for more amperes. (The short version of that is, "Volts push amps through ohms.") To be truly useful to us, we must know something about the way these three basic units relate to
You don't have to be a football expert to sit in the stands on a nice fall day and watch the locals bash the visitors. But to get the most from the festivities, it helps to know the difference between a two-point conversion and an on-side kick. Being able to converse with your seatmates about the nickel defense and the single-wing offense surging back and forth before your eyes makes it even better. The jargon isn't just for the players and sportscasters. Electricity is a bit like that. Most of us are users, and most of us know some of the jargon despite the fact we don't work at a power plant. We know that we have 12-volt batteries in our cars and that the porch light takes a 60-watt light bulb. And for many folks, that's enough. I believe, however, that those of us who work with things electric on a larger scale can benefit from
The triennial publication of the National Electrical Code is an event of critical importance to any contractor or subcontractor performing electrical installations or repairs. First published in 1897 and produced since 1911 by the National Fire Protection Association, the NEC is now enforced in all 50 states and also serves as the basis for codes in several foreign nations. As has been the case with all editions published to date, the 1999 edition of the code is designed to ensure "the practical safeguarding of
