Wednesday, June 6, 2012

Lessons from a nearby lightning strike

We had long discussions over the failure of the ERV during the nearby lightning strike - the ERV engineers have apparently only seen this type of catastrophic failure on their system one time before and that was due to a direct strike by lightning.  The suggestion was to claim this on our homeowner's insurance but the deductible was nearly the cost of the repairs so that option did not make much sense.

In our research regarding lightning strikes I discovered thatsurge suppressors on the market today that I could find carried guaranteed protection for power line surges but carried strong caveats that they were not for direct lightning strikes.  I did manage to find a couple of lightning suppressors on the market that are designed specifically for lighting.  One other caveat that was on a number of the surge suppressors was that they only protected the electrical and if another "line" (e.g. telephone, network, cable) was connected but not through their surge protector their warranty was not in effect.  In one case the warranty clearly stated that their device must have failed for the warranty to be valid.  Several had time limits on their warranty but some had limited lifetime warranties and others had lifetime warranties.

Our solution is a two-fold approach.  I've purchased whole-house surge suppression (Eaton Whole House SurgeTrap) for the electrical panel as well as the TV and telephone service entrances which state they are good for surges and lightning.  In addition I've purchased a panel-mounted lightning arrestor (Delta LA206R) that is sacrificial - basically it acts like a fuse and blows when there is a lightning strike.  In addition to the whole-house surge suppressor and lightning arrestor we are purchasing new point-of-use surge suppressors for all our electronics (computers, TV, satellite equip, refrigerator, stereo, ERV).  The one issue that remains is the heat-pump water heater and ground source heat pump which are both directly connected to the panel so those plug-in units won't work (plus they are operating at 240v, not 120v as are the house outlets) so I have to make sure the whole-house units provide sufficient coverage for these expensive units.

We did consider putting in a whole-house surge arrestor offered by the power company but that too carried the "does not protect against lightning" and it also did not provide coverage for electronic circuits.  The ONLY protection it provided was for the motors and compressors in household appliances.

The suppressors carry warranties for connected equipment anywhere from $10,000 up to $50,000 and range from 2 years up to limited lifetime.  Of course you have to prove that the damaged equipment was properly connected through the protection device and meet all other conditions but at least there is some change of recovering the costs in the event of a catastrophic lightning strike.

One point that I may not have mentioned is that our utilities are all underground - and there are the mandatory two ground rods separated by 8' installed and connected to all the service entrances (tv, telephone, power).

1 comment:

  1. hi. thanks for such a detailed review.I hope it inspires many to install such protective measures.

    Lightning Arrestors