Residential Grounding and Surge Suppression

When my home was built in 1991, I built a grounding array within 4-feet of the service entrance meter and panel. It consists of three,

5/8-inch, copper-clad, 8-foot ground rods. They are placed in a "goal post" configuration with the two verticals about 7-feet apart and one crossing the top of them, perhaps 6-inches below the tops of the rods. There is probably a 18-inches of earth cover. All components are bonded together with two, #6 solid copper wires and two make the final run to the meter box.

Given midwest weather, I am confident that we have had plenty of transient spikes in the intervening years but I have experienced no (apparent) damage.

During this time, my computer system has been ostensibly protected by a strip-type surge suppressor:

I recently installed an Intermatic (whole-house) surge suppressor.

I have been following the Intermatic thread with some interest. Admittedly, it got a bit "deep" when the engineers began debating. Still, I gathered much good information, not the least of which was that MOV (metal oxide varistor) surge suppressors "wear out" over time - that their efficacy diminishes with each surge.

Is it time to replace my strip-type suppressor? The LEDs indicate nominal operation and protection, for whatever that's worth. TIA.

Reply to
Jim Redelfs
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That has got to be the oddest ground rod configuration that I have ever heard of and quite possibly one of the least effective. For optimum results, eight foot rods should be at least sixteen feet apart.

Reply to
John Grabowski

No. If it's got an indicator that says it's okay, it's okay. Probably.

If it's got lights, it's not the cheap-ass, one-time-Charlie kind.

Presumably this surge protector is upstream of the UPS (which has even more surge and spike protection).

Reply to
HeyBub

MOVs will continue to clamp surges until they fail. With high ratings, readily available in some plug?in suppressors, they will likely never fail - one reason some of them have protected equipment warrantees.

Should you replace your plug-in suppressor? Who knows. How old? Lot of lightning storms? Suppressor turned on during a lot of storms? Short branch circuit wire length to panel?

With your service panel suppressor, the plug-in suppressor should get less action. I would probably keep it.

I would look for a UL 1449 *2nd edition* listing on the suppressor. These are produced after about 1998.

The protected load can be connected (1) across the MOVs or (2) across the incoming line. If connected across the MOVs, the protected load will be disconnected if the MOVs fail and are disconnected. I believe new suppressors are required to say if they are connected by method (2). Added protection of connecting across the MOVs is another reason some suppressors can have protected equipment warrantees. Unfortunately it is not easy to tell which way a suppressor is connected.

All interconnected equipment needs to be connected to the same plug-in suppressor or external connections, like phone wires, need to go through the suppressor. If your computer is not connected this way you should change the configuration. This is very important.

One of the suppressors I am using has a (total) rating of 1770J,

90.000A. It cost under $30 and has a protected equipment warrantee. I don?t plan on ever replacing it.
Reply to
bud--

Aw, I'm crushed! :/

Given I consulted NO guide in building my first grounding "array", I hope that, at least, "more-is-better" is TRUE in this case.

Do you believe that the "array" I installed is less effective than the SINGLE rod and wire that WOULD have been installed by the same, hurried electrician that neglected to bond the water system to the electric service or install the water meter jumper in 1991?

Oh, fer pete's sake. I'm not erecting a broadcast tower!

Everything is a gamble. I expended a little, extra time and built what I thought was (and still think is) better than what WOULD have been otherwise installed. Now, with my whole-house suppressor and a presumably properly operating plug bar system, I'm going to sit back and enjoy my computer system even more. I can further relax knowing that, finally, my entire home is "protected" from transient, electrical spikes.

Reply to
Jim Redelfs

"not less than 6 feet apart". There is a footnote that says if the rod is longer than 8 feet, it would benefit from a greater distance, but doesn't indicate any improvement with 8 foot rods

Reply to
RBM

The NEC specifies that 8 foot gournd rods are to be spaced 6 feet apart. Usually two rods are being used now.

Reply to
Ralph Mowery

Sounds like you are in pretty good shape. Other than a direct lightning strike to your house, you will probably survive most spikes that come into your house from the power lines. I always leave my external hard drive completely disconnected as a precaution as well. You do back up your data -- right.

Reply to
Jeff

Sounds pretty good to me for residential application. Do you use couple of ground wells and keep it wet? How about connection to a rebar a la Ufer ground?

Reply to
Frank

If an indicator light reports failure, then surges far exceeded what that protector should have ever seen. Properly sized protectors only degrade - normal and acceptable failure mode as listed on manufacturer datasheets. Degrade means indicator light reports no failure and protector remains functional.

Failure light indicates a failure that a protector should never experience.

Surges occur typically once every seven years. A number that can vary even within towns. A number also changed by things such as geology or even buried utility pipelines. Do not even assume mountaintops suffer more surges.

How frequent were your surges? Best answer comes from canvassing a neighborhood for damage history over the last decade. Chances are surges were so trivial that the protector earthed them with near zero degradation.

If surge damage is frequent, then a larger 'whole house' protector (higher joules) could also be installed and earthed. Both properly earthed protectors mean a significant decrease in 'degradation' inside each protector - longer life expectancy.

In most situations, a 'whole house' protector is good for decades. If not, a larger joule protector is installed so that it does not degrade for decades.

Why do MOVs have a bad rap? A plug-in protector maybe so grossly undersized that a light even indicates the unacceptable failure - MOV violated manufacturer acceptable operation. A protector must be properly sized so that it never reports failure on that indicator light. Light will never report a degraded protector. Light simply tells the human that he has installed a grossly undersized and unacceptable protector for that location; that the protector did not provide effective protection.

Let's put some numbers to life expectancy. For a 100A surge, life expectancy of a 45 joule MOV is 2,000 surges compared to 80,000 for the 382 joule MOV. 8 times more joules results in a 40 times increase in life expectancy. A joules increase, protector life expectancy increases exponentially.

Reply to
w_tom

Hi bud, I want one of those. What brand is it?

-- John

Reply to
John Ross

Right.

I have been backing-up my stuff since my very first hard-disk drive. It took an expensive stack of high-density, 3-1/2-inch floppy disks (1440k) to back up my very first hard-disk drive, a 20 megabyte internal. It took a good portion of a day playing "musical diskettes" to get the job done.

Of course, 2400 baud was the latest and, when I finally replaced my 20 megabyte drive, the Quantum 210 MB raw drive was $950!

Today, I have my 250 gigabyte Seagate "Barracuda", internal hard-disk drive FireWire-connected to two, 250 gigabyte, LaCie "Porsche" external drives.

Apple's Mac OS X 10.5.2 "Leopard" includes "Time Machine", a fully automatic, virtually transparent back-up utility that runs continuously in the background. After the initial, global back-up, Time Machine saves hourly backups for the past 24 hours, daily backups for the past month, and weekly backups for everything older than a month until the target volume is full. It's awesome.

Everything is "in" my hard-disk drive now. Everything that is important to me: My photography, my music (more and more of it downloaded) and my money (Quicken).

Hard-disk drives and back-up solutions are so CHEAP anymore that there's no reason to not have a current backup.

Windoze XP is getting a bit "long in the tooth". Perhaps your computer is, too, and Vista either won't run on your old system or just the thought of the upgrade drives shivers down your spine.

There's no better time than the present to make the switch to a system that is rock-solid and faster than a speeding bullet.

Figure out the web site URL in my address above and see the integration between iPhoto and Apple's .Mac (pronounced "dot mac") service. I select the digital photo album I wish to post on my website, push a button, and it happens just like you see it there.

I'm having a ball using Mac OS X 10.5 "Leopard" on my four-year-old G4. I am DYING to get a new Mac but this one still does what I like most, albeit more slowly every day.

The new Intel Core2 Duo Macs flat-out SMOKE. One can only imagine the speed with the Mac Pro running Intel Xeon 8-core: Two 2.8GHz, 3.0GHz, or

3.2GHz Quad-Core Intel Xeon 5400 series processors.

Enough evangelizing for Apple. I probably ought to buy some of their stock.

Yes, I always have a backup.

Reply to
Jim Redelfs

I bought a couple of different Belkin suppressors that were on sale at different times at Micro Center, a chain I like with only about 20 stores (but no doubt online).

Reply to
bud--

But, but , but... Why would you buy suppressors at a retail store? According to W_Tom, you own the factory that makes them!

Reply to
salty

The rotten bastards are all on strike. Even the illegals. They were infiltrated by communists and Democrats and now think I shouldn't be allowed to abuse them. I have contracted with an Italian social organization to fix the problem.

Reply to
bud--

NJ unemployment insurance is only good for 13(?) weeks. Tony Saprano could probably use the work about now.

Reply to
w_tom

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