Whole House Surge Protection
Can a whole house really be surge protected?
Contributed by Paul Lupton
Readers have raised an interesting question which deserves a somewhat detailed answer to a technical question. The question goes:
“If surge protectors are required for so many devices in my home why couldn’t I just put one at the electrical entrance to my house and save all the individual ones?”
Indeed, this is probably a question that could be asked by most home owners.
Having done a fair amount of house wiring including the installation of the meter pedestal and breaker panel, but not being a licensed electrician, I thought I better search the web for some authoritive answers. I was surprised how easily I uncovered not only the answer but a broader understanding of the subject.
The short answer is that it is not only possible but it is (for an electrician) a modest installation project. The cost of course is another matter. For the reader who wants to jump to the heart of the matter and skip my explanation go to CareBase.com. This user friendly site offers a wealth of information about products that can solve the problem. The meter based unit runs about $300 and must be installed by the power company. Hardwire units that can be installed by the owner or an electrician are in the $200 range.
A call to Mike Gibson, webmaster and factory rep was very helpful. He directed me to one of his favorite links hosted by the National Institute of Standards and Technology, NIST, (a fascinating glimpse into how some of our tax dollars are spent). This site contains a downloadable 24 page brochure (titled: Surge Happens!) that reveals more than you probably want to know but will thrill anyone with a thirst for technical details. Basically, it gets into the many forms of electrical surges, their sources, and devices that will deal with them. NIST, is a government funded but non-regulatory branch of our federal government that is charged (sorry about the pun) with the task of communicating information to the public that will make them better informed consumers of electrical and technical products, among other tasks.
For those readers who want a capsule of the information I uncovered, here are a few broad topics…
What are “surges” and where do they come from?
The technical term is actually “transient voltage spikes”. Many people assume that lightning is the main culprit. Actually, lightning, though a powerful jolt to the electrical grid, is the least frequent source of the problem. Electric utilities have to cope with lightning as a routine matter and have devices to protect their own transformers and switching gear. Many of these surge protectors are of a “spark gap” nature and essentially cause these extreme voltage spikes to harmlessly bypass the transmission grid hardware and be directed into the ground. Interestingly enough, home owners with external antennas already have some protection against lightning by this method!
The most common sources of surges are large power consuming appliances with electric motors. For example air conditioners, refrigeration equipment, power tools, welding equipment, elevators, etc. These can be in or near the home or even miles away. Amazingly, even the sun itself can emit powerful disturbances that at times can affect even the power grid!
The power company itself can cause transients when loads to entire communities are shifted to different generating sources. Although normal house voltage is 120v AC, these transients can be 300v, 400v, or more! Sitting in your home reading by an electric light you will be unaware of these voltage spikes because they are very brief and are not harmful to many regular appliances such as incandescent lights, toasters, washing machines (older types without computer integrated controls) hair dryers etc. The reason these spikes are relatively harmless to these appliances is they are extremely brief. Their duration is measured in nanoseconds (a billionth of a second!)
Computers, home entertainment equipment, alarm systems, smart phones, etc. all contain electronic chips that operate through microscopic semi-conductor circuits at very low voltages. As more and more appliances have become “smarter” they include chips vulnerable to surges. Transients are the enemy of these tiny wonders. Whereas a hair dryer already produces heat, these spikes are mere pebbles in the torrent of electrical “boulders” that course through the heating element.
For a semiconductor chip these spikes may be enough to toast the conductors or junctions and either cause immediate failure or weaken them sufficiently so that future spikes will bring their demise. Because computers have so many functions using different circuits, damage may have occurred to a circuit that is infrequently used. The appearance may be created then that no damage has occurred but the flaw lies waiting for the next time a certain function is used!
As mentioned above, Michael Gibson, a founding director and third president of the non-profit Colorado Electrical Service Network, hosts a very interesting and extremely useful website, CareBase, dedicated to understanding the nuances of the world of transient demons. My call revealed a telephone personality reflecting the spirit of the website: knowledgeable and friendly. He pointed out that if you think that newer circuits are more tolerant of transients, think again.
“Electron therapy” has now become especially important, as Intel, AMD, Samsung and other computer chip circuit pathways have shrunk to a microscopically small 65 nanometers wide. That’s about 1/500th the thickness of a human hair. The new process technologies allow the chips to use less than 2 volts, and 6 watts. The amount of excess electrical energy in a surge that it will take to burn out one of these microscopic pathways is now significantly less than even 3 years ago. Properly coordinated high quality power voltage regulation and surge protection is now needed more than ever.
The good news of course is that these devices are smaller, smarter and use less energy. The bad news is that their microscopic electron pathways are extremely delicate. Fortunately many manufactures include some surge protection in the appliance/device itself. Study the user manual or contact the manufacturer for some idea of the measure of external protection needed. They will probably recommend some just to cover themselves. Unfortunately you can’t test the device to see how much it can take. Well actually you could but to learn the answer would require paying a repair bill or purchasing a new unit.
Technology to the rescue!
Sooo, if you believe that if technology created the problem, technology can solve it, you are right! Naturally, the old caveat still applies that money can solve almost everything. The website mentioned (CareBase.com) is not a shopping site, prices are not given, although they maintain a relationship with numerous manufactures. No less than seven distinct approaches are available to solve the problem. (And you thought power strips with surge suppressors were it! Actually I knew of a few more but thought they were pretty exotic and uncommon). The ultimate surge protection is to unplug the device if an electrical storm is present. The antenna wire, coax, or phone line must be disconnected too. Realistically that only works if you are home 24-7 and are willing to interrupt the use of your equipment.
Briefly, surge protection methods include devices such as isolation transformers, DC to AC inverters, transfer switches, uninterruptible power supplies (UPS) and several others. If you are really serious about investing in these devices it may be worth investigating whether the devices contain any environmental toxins.
In Europe a standard known as RoHS, Restriction of Hazardous Substances, adopted in 2007 has become a model for global manufacturing. Wikipedia has a long detailed article on RoHS worth a read if you are curious about being as green as possible. Essentially it is a directive to manufactures to restrict the amounts of heavy metals (lead, mercury, cadmium, and four other substances). Several of these have been staples in electronic manufacturing for years and are now being dealt with due to their persistence in the waste stream.
A logical question arises about the number of devices necessary. Although a surge suppressor on a certain branch circuit provides maximum protection to that circuit some benefit accrues to other circuits. For that reason appliances in remote parts of the home probably are on different circuits and would profit from their own protection.
An interesting footnote to my discussion with Michael Gibson was the topic of the power company itself providing a device. He asked who my electric supplier was. I replied and he wanted to know if it was a for-profit or non-profit company. Mine is for profit. The difference can be their attitude about installing meter based solution for free or a fee. Naturally all companies are protective about any tampering with the meter hardware. The meter based solution, however, is a quick clean answer not requiring any modification to the house wiring. Transients generated within the home, however, may not be addressed and would still require the individual suppressors at the wall outlet.
So, in the end, what to do? Modern life offers so many choices. Everyone must study their unique needs, their budget, known presence of surges, risk tolerance for repair bills, and the need to sleep well. Good luck.
editor’s footnote: The impetus for this article originated from a discussion at the Tiny Houses discussion group at Yahoo!, brought up by “Jill from Seattle”. I secretly deferred the question to my Dad to see if he knew anything that I could pass along to the group. I never anticipated he’d write a whole article on it! Thanks so much, Dad, for researching this. I knew if, at least, you didn’t know the answer you’d be able to find it out. Thanks!
