I've been looking at whole-house surge supressors and in my travels I found something interesting at the Intermatic web site. I noticed this device:
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which looks very similar to something we already have attached to our outdoor electric meter box. Unfortunately ours has been painted over so I can't read the writing on it to see if it is indeed a "secondary surge arrestor", but it's shape looks exactly like this Intermatic unit so I'm guessing it is.
My question is, what does this device do as compared to the whole-house surge supressor like the IG1240R (also sold by Intermatic)?
One reason I ask is that we had a damaging surge during a close lightning strike when we first moved in (2001). The house was new in 2001 and the device above was always attached at the meter box, so I'm assuming it's not meant to stop lightning surges (either that or it's just not working ). We lost our electronic sprinkler controller, a VCR, and an electronic phone. The VCR actually smelled like it was burning after the lightning hit! (BTW, the lightning was close, but did not hit our house directly. We never did find any evidence of exactly where it actually did strike.)
If this is the case, how do people protect the expensive equipment attached to cell towers, ham radio towers, TV and radio transmission towers? I have to imagine these towers get their fair share of lightning strikes. I can't see the TV stations unplugging their transmitters atop the Empire State building every time a thunderstorm approaches.
The difference is, they have elaborate grounding systems that take the lightning strikes. If you want to spend a few thousand dollars you can do the same for your house.
'Whole house' protectors are secondary protectors. The primary protector is that utility transformer earth ground wire that is so critical to household protection.
Surge protectors do not stop, block, absorb, or filter out surges. They do as Franklin demonstrated in 1752. He intercepted lightning that sought earth ground through a church steeple. Lightning will also chose the shortest path to earth ground by striking AC power line and using paths, destructively, through appliances. But effective protection from direct strikes has long been proven. Lightning seeks earth ground. The secondary protector shunts (connects, diverts) lightning to earth IF located at the service entrance AND IF if it creates a less than 10 foot connection to central earth ground.
Therein is the protection. Not the surge protector. Earth ground is the protection. Many locations have sufficient grounding IF only installing an eight foot ground rod. How good is the earthing? Geology is a major factor. Some will install halo grounds around a building just so that they need not discover the single earth ground rod is not sufficient.
What is that attachment on meter box? If it is a surge protector, then it must have a connection from every incoming utility wire to earth ground. If it is an effective surge protector, then that connection will be less than 10 feet and meet other earth connection requirements.
Damage is most often due to insufficient earthing. Many places need very little earthing to be sufficient. Others require a more comprehensive system. But every incoming utility, including phone and CATV, must connect to that earth ground.
Described is a classic example of AC electric surge. Surge sought earth ground. It found earth via sprinkler system, VCR, and base station to a portable phone. Notice every damaged item had both an incoming path from AC electric and an outgoing path to earth ground. For example, incoming on AC electric, through VCR, and outgoing to earth via cable. Incoming on AC electric, through base station, and outgoing to earth via phone line.
Phone lines already have a 'whole house' protector installed in the premise interface box (often labeled NID). But again, the protector is not protection. Protector, provided free by telco, will only be as effective as the protection connected. That surge protector will only be as effective as central earth ground.
Too many see surge protector and think that is surge protection. Then when damage results, they will say, "No surge suppressor is going to protect you from a close lightning strike." Ironic that the better a surge protector, then the less warranty offered. The benchmark in surge protection is Polyphaser - who offers no warranty. Their products and application notes are legendary:
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Application notes don't discuss their products. Notes discuss the most critical function of a surge protection 'system' (which is why that ground from utility transformer is so important for the primary surge protection). Another less technical discussion about earthing is found in the newsgroup misc.rural entitled: Storm and Lightning damage in the country 28 Jul 2002 Lightning Nightmares!! 10 Aug 2002
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or
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Even very little earthing can massively increase surge protection. But the bottom line remains - a surge protector (the science) is only as effective as its earth ground (the art).
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Well I assert, from personal and broadcast experience spanning
You suffered surge damage because the strike found a better path to earth ground via household appliances. All appliances already have effective, > Hi,
My house (a 150-year old farm house) has a metal roof with two lightening rods sticking up, and two metal cables running down over the roof and buried in the ground. Since I'm up on a hill I am sure It's been hit more than once in the 21 years I've lived here, and there's never been any lightening damage.
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