Thursday, January 28, 2010
Friday, January 1, 2010
Why Surge Suppression?
Surge suppressors, also called surge protectors, stop voltage spikes from harming your electronic appliances in the home. One type connects to the main electric panel off a circuit breaker or directly between the meter and panel, while the more common type are point-of-use surge protectors for electronics such as computers, telephones, printers, etc. You often see the latter integrated into office-style strip outlets or better yet, back up battery devices (like those made by APC). We have several of these that our computer systems and TV/Stereo systems plug into - a few years ago a broken electrical pole next to the house sent a spike through the cable system frying the cables and knocking out the suppressor on the TV - since we were out of town when it happened all the computers, modems, etc were off so they weren't affected. The suppressor on the TV/Stereo protected all those components as the cable fed into it, saving us a bit of money in replacement costs (or at least the deductible on an insurance claim). Not to mention the threat of a fire - having suppressors just makes good sense.
Electrical disruptions in power are real and they are becoming more of a threat to electronic equipment regardless of whether or not you live in a new home and constant fluctuations happen all the time in my neighborhood. A voltage surge or spike caused by a blown transformer (which happened just a few days ago on my street), downed power lines (ditto last year), lightning, electric power grid switching, etc. are all examples of what can happen to affect your home's systems and appliances. Additionally, over 50 percent of the power surges your electronic equipment will experience are created within your own home when appliances with large motors (air conditioners, refrigerators, washing machines, compressors, etc.) turn on and off. What's more, most electronic devices manufactured today contains micro-processing chips that are sensitive to voltage spikes - even your light bulbs are affected. If your light bulbs seem to wear out quickly then you're probably already experiencing fluctuations that the whole house suppressor can help smooth-out. You need surge protection and lots of it if you want to protect everything connected to your house grid.
The focus of this post is a whole house surge suppressor (I'm hoping most of you already have the type that connects between your more expensive equipment and the outlet). These devices are designed to stop harmful surges and spikes before they can travel towards the electronic equipment in your home. They are not DIY friendly so my recommendation is for a professional, licensed electrician to install a whole house suppressor. A good electrician can complete the task in less than one half hour in most cases and the suppressors are affordable as there are several in the $200 range (figure in about an hour of an electrician's time and you'll see it's not out-of-reach). When calling around you may want to note what type of panel you have (it's usually marked on the panel or you may be able to find a manufacturer on a breaker) as it could reduce the costs of the unit - there are some that install directly in the panel where the first couple of breakers sit in the box.
My Electrical Panel
In my case our home has a 150 amp Cutler Hammer panel with corresponding breakers. I mention that as it's unusual in Northcrest to have 150 AMPS and an original panel from 1964 (when the house was built) - most homes on my street built around the same time have 80 amp fuse boxes or have at some point been upgraded to a 100 amp panel. Apparently the original homeowner of my house sprung for the additional costs - this is both a boon (as the larger panel makes changing things more flexible) and a curse (Cutler Hammer breakers are a great deal more expensive than other manufacturers for some reason, so it can be difficult locating what is needed, especially at a reasonable price). I went through all this last year when I started building out a workshop in the basement - first adding a 100 amp sub-panel dedicated to the equipment, and then finding tandem breakers (those are breakers that make two switches available in the same slot as one - allowing me to move circuits down to make room for the larger, two-pole breakers necessary to power the sub-panel). Once again I needed to move things around to make room for the 30 amp two-pole breaker needed to power the surge suppressor. While in the panel I freed up the first two slots for the breaker required for the suppressor, which hangs off the side of the panel. Finding two tandem breakers wasn't difficult - but at $25 each rather expensive. I found a seller on eBay that had four new tandem breakers for $25 shipped - much more reasonable (as a comparison a single comparable SquareD tandem breaker is $7 at Home Depot).
Choosing a Surge Suppression Unit
There are a variety of units available but in general there are a few things you need to look for:
- Joule ratings of 1,900 or greater - Suppressors work the way they do through the use of sacrificial metal oxide varistors (MOVs). Small surges that enter your home over time slowly destroy the MOVs. A large surge can cause instantaneous destruction of all of the MOVs in an instant (you want the MOVs to take the load instead of your appliances and components). The MOVs ability to block surges is measured in joules (how electricity is measured, also called a Newton-Meter). Purchase a surge suppressor that has a high joule rating - 1,900 or more if possible.
- Clamping voltage is the next thing to consider - This rating tells you when the surge suppressor will react to a surge. High quality suppressors have low clamping voltages - the suppressor should have a clamping voltage of 330 volts or less. The package will have a Underwriters Laboratory (UL) UL-1449 voltage rating - this is the true measure of clamping voltage.
- Warning Lights - Because surge suppressors wear out (due to the MOVs being constantly worked), look for a unit that has lights and/or audible alarms that tell you when the MOVs have worn out. Both the whole house and point-of-use surge suppressors are available with this feature.
- Replacement Warranties - Look for suppressors that come with connected equipment and total replacement warranties. Numerous manufacturers will send you a free replacement suppressor when and if yours fails - so the initial cost of the unit pays for itself the first time it fails (provided it happens during the warranty period - most warranty for 5 years or so) - some will pay up to $100 towards the electrician's repair bill when your whole house suppressor needs to be replaced. The better units I researched will also cover repairs of appliances and/or devices if the unit fails to stop the surge.
I tackled the install in three phases (being the anal-retentive that I am, I actually wrote up a short project plan).
- Examine the panel and make a plan, including picking up all components and parts
- Rework the panel to have room and prepare all components
- Install the unit and test.
The second part I tackled one evening while there wasn't anything going on that would require power - I like to disable the entire panel by turning off the main switch while in the box. I'm still very careful as there's still power coming into the panel - but this way I'm not inadvertently taking any risks. I moved circuits around and combined into the tandems to leave the first two slots free. This took about 30 minutes or so of careful striping, wiring and the screwing of clamps (in the breakers)
A couple of days after the install I was at Allen and Susan's house - it had been raining most of the day and there were several people over for Christmas dinner. Suddenly there was an explosion that caused us all to rush to the front window. Subsequent explosions literally lit up the sky - the transformer right in front of his house (he's about 3 doors down from my house) had been hit by a falling limb - luckily the wet ground prevented any of the flaming embers from igniting anything. It took several hours for Georgia Power to restore power to this portion of the neighborhood. All I could think about was how fortunate I was that the Surge Suppressor was already installed at the house - it provided a level of piece-of-mind that I wouldn't otherwise have felt. Returning home later I found everything to be fine - the unit worked flawlessly.