Considering that most homes have 200 amp electrical service, a whole house system would mean needing protection for 24,000 volt-amps or watts (if power factor is not considered). That equates to a very large (and from my perspective, expensive) device. I am mostly familiar with industrial line conditioners that are typically isolation transformers with additional filtering and do more than surge suppression. For one of those capable of a few thousand watts, still far less than 24,000, the cost was several thousand dollars nearly 20 years ago. Considering that most household loads are not sensitive to surges short of a lightening strike, whole house protection is not really cost effective just to protect a few, relatively small, but sensitive electronic loads.
Over the years, I've encountered computers and other sensitive electronics that suffered from baffling intermittent or irregular failures. After some frustration, an AVR type line conditioner was installed and completely cured the problems. While I have no experience indicating an AV system would benefit from an AVR line conditioner, it seems plausible that this might be a worthwhile addition. I've had success with Tripp Lite and APC systems that are relatively inexpensive, and with the APC systems can be combined with a battery backup to prevent loosing a video recording due to a power outage.
As noted, power conditioners only protect equipment from power surges. Other devices would be required for rf and phone lines. When I used an outdoor antenna, I did install a surge protector in the coaxial downlead, but I've used no other protective devices in my systems over the years. While my experiences may not be typical, I have had no surge-related failures to any equipment attached to rf or phone. I have used a cable provider for all communication services for some time with no additional protection in areas that receive severe electrical storms. The cable and phone companies have surge protection to protect their inline equipment, so the likelihood of a surge being transmitted through the line is quite small. A ground transmitted or induced surge from a direct or near lightening strike is much more likely than one coming down the phone or cable. However, protective devices can be acquired quite inexpensively to provide additional peace-of-mind. I have heard rumors over the years that such devices are everything from ineffective at blocking surges to having an undesirable effect on audio and video, none of which I have personally substantiated. I have not noticed any anomalies in my system over the years using various surge suppressing power strips including the two Belkin ones currently in my system. However, these were purchased for their relatively low cost, number of outlets, power rating, and heavy-duty cord over any claims for surge suppression.
Most household surge suppressors feature MOV devices that are designed to switch above a certain voltage and shunt the excess energy to ground, bypassing the equipment connected past the MOV. The MOV device has a certain capacity rated in joules or amps. Surges caused by lightening can be far greater than the MOV capacity. In this case, two things can happen: the MOV will fail open or fail shorted. If it fails shorted, the circuit protection device, aka circuit breaker or fuse, will open (trip or "blow"). If the MOV fails open, the surge continues down the line into all of the equipment connected to the suppressor. Also, if the MOV fails to switch quickly enough, a very good possibility with lightening-caused surges, the energy will still get past the MOV and to the equipment before the MOV can react. In my opinion, the manufacturers and retailers of common surge suppression devices and their insurance providers are relying on the relatively low probability that any equipment attached to their devices will actually ever see a surge, and, as a result, they'll have a low probability of ever having to pay out a claim.
I am curious, though; has anyone filed a claim regarding a surge suppressor failing to protect their equipment, and how was the payment response on the insurance?
Best regards,
Bill
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