We’re getting ready to set up our electric metering distribution panel (not sure what exactly to call it), for the power company to hook up to. It’s a 400 amp system and will feed the house and a machine shed. We went with 400 amp because there was very little difference in cost, the geo-thermal installer said we may need it.
A few years ago the power company was advertising a whole house surge suppression system.
Any feelings one way or another about such systems and where one can get them?
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I've looked into these off and on. If I felt that a system was truly reliable, I'd do it.
The problem I keep running into is, "How do you know if the system has been compromised?". Back in Maryland, PEPCO offered one that you "rented" that plugged into the meter. I called ot ask how often the unit was checked, and nobody had any idea. I wasn't about to pay $10 a month for something that I could not verify was still in a condition to stop a surge.
Surge supression is something that slowly degrades whatever is being used for suppression. In my mind, that means it should also indicate its current status and tell me when it needs to be replaced.
There is a pretty decent article somewhere on the web explaining some of the options. Unfortunatley, I've lost my old links, so I don't know where I found it.
Surge supression is something that slowly degrades whatever is being used for suppression. In my mind, that means it should also indicate its current status and tell me when it needs to be replaced.
While not a whole house suppressor, the surge suppressor that our A/V equipment is plugged into is supposed to shut off (as in stop providing power) once it is no longer able to protect your equipment.
Part of the point of a whole house surge suppressor is to NOT go down. Otherwise, everything in your fridge spoils, etc. etc. That means you need to know when it needs to be serviced (exchanged or whatever) BEFORE it reaches the failure point. And they don't seem to do that.
I've done a fair amount of research on surge suppressors since our house has suffered two lightning strikes/near strikes.
The first lesson is that nothing is 100% effective against a direct lightning strike. Service panel suppressors (i.e. Tytwadd) or meter can suppressors (i.e. elec. utility provided) provide some protection against a surge entering your house from the service drop. If you are in a lightning prone area, I'd recommend them. If you feel you need (and are willing to pay for) the insurance policy offered by the electric company, go that route. Otherwise, use a panel-mounted suppressor (cheaper, equally effective IMO, but usually no insurance).
However, if you take a direct hit, or near-hit, current doesn't necessarily enter your house through the service panel. Lightning can induce current in any wire in your house, even if you have a top-notch lightning rod system taking the charge to ground. So the spike enters the system downstream of the service panel, rendering the service panel suppressor useless. In this case, you need suppressors at the point of use, and even then there is no guarantee they will work.
Also, if you use strip outlet suppressors, it is important to use the kind that includes coax & telephone wire connections, too (where applicable). Surges can run through these lines as well, and the voltage differential will kill your electronics.
nothing is 100% effective against a direct lightning strike
Your appraisal of 'sneak paths' is correct, the whole house topology electrically needs to be considered - even the water and sewer pipes for 100% protection.
As for the surge supressor part failing, is true of HO stuff bought off the internet, but it is possible to protect 100% (and even continue operating!) after at least the max 400 kA strikes I've tested to. 99.99% under 200 kA.
You can't afford them though unless megabuck guy (or DIY for a few 20's assuming you have a diamond rock saw, machine shop, etc). The 100% effective ones I've built went into Minuteman and Peacekeeper missile silos.
If I get time oneday, maybe will write up a BT treatise on surge protection like Frenchy did for forklifts.
BTW, those $5.95 or $10 per month supressors are worthless, even went to the trouble of reading the warranty on one once for kicks, truly worthless and false security.
Junkhound, do you have any experience with Transtector brand surge suppressors? They're based in Idaho, I believe, and use proprietary avalanche diodes in their equipment. I'm an EE, and we sometimes use their equipment on commercial projects. It seems to be good stuff, but how does one know for sure...http://www.transtector.com/
Stuart,
I read about this company and their ideas regarding ground transients...http://www.9corp.com/dataplots.htmlthe company claims they have figured out the hardware and circuitry to prevent spikes entering through the building Ground !I have not used any of these , but the possibility of being able to finally prevent transients, with repeatability, may be attainable.the GTT looks like it mounts in a typical j-box, to protect branch circuits individually, instead of trying to protect an entire panel"
Had not heard of this company. Basic premise of needing to protect the 'ground' (like water pipes even) is sound. Hype of the web site prevented me from reading further.
I have to agree with you about that site , I have looked at it for a few months now and it seems to be getting worse with all the bells and whistles.
..
these guys seem intent on repackaging what they initially developed, to fit every possible angle.I still like the idea though......"
None, but any website that has flashing headers yells "NO TECHNOLOGY< JUST HYPE" at me. Did not bother to read further.
Some of the behind-the-meter units used to be gas discharge, and essentially immune to "burnout" (though painfully slow operating). Not sure what technologies are used now.
No electrons were harmed in the making of this post.
Gas tubes in series with a silicon carbide varistors were the item of choice till about 1975, then metal oxide varistors (Panasonic invention i recall) were able to accomplish the same function for a less expensive device.
Gas tubes were not slow, some I tested established and arc with only a 12 volt drop at 200 kA within 6 nanoseconds!. Some of the best vendors of those devices left the business, e.g. Joslyn.
I think they are definitely worth the money. Cheap for the protection they provide. Check out this comment. http://forums.taunton.com/tp-breaktime/messages?msg=61668.18
"CHeap for the protection they provide"
Whoops, almost made an eggregious error of responding before I read the link to your original post. Thought you were recommending the $10/moth crap!
Everything in your original post is accurate, thanks for the link.
If I get time oneday, maybe will write up a BT treatise on surge protection like Frenchy did for forklifts.
So Art, when can we expect this article?
I've moved to the land of lightning.
In Utah the Iron Mountain iron mine across the valley was pretty interesting, I managed to take 2 pictures of lightening one night. Here it's all around.
Joe H