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Why whole house surge protectors are not enough

TL;DR:

One measure of a surge protector is the clamping voltage. That is, at what voltage does the surge protector actually start to work. Whole house surge protectors are limited to no less than ~ 600 Volts (instantaneous) between a leg and neutral or ground. That’s up to 1,200V if symmetrical.

The best surge protecting strips and conditioners clamp below 200 Volts.

Please keep this in mind when deciding whether or not to use surge protectors at your PC, stereo, TV, etc. in addition to a whole house unit.

I wrote more about this here:

 

https://inatinear.blogspot.com/2021/09/time-for-new-surge-suppression.html

No manufacturer of whole house surge protection claims that their devices alone are enough for sensitive electronics when you check the fine print.

erik_squires
upshift
65 posts
 

I'd like to second your callout regarding surge suppression and LAN protection from your blog.  A few months ago we had lightning hit a tree that was just 15 feet from our electrical entrance with is underground. It took out 2 TVs, 2 UPSs, Router, 3 Switches, BlueSound Node, and the Inverter for my solar system, One of the UPSs actually smoked!  One TV would not even power on, the HDMI ports and LAN port did not work on the other.  I suspect the static charge traveling through the LAN as taking our the2 TVs and the LAN equipment. Strangely enough, the cable modem was not damaged.  I have since added lightning arrestors to the cable and LAN networks. 

upshift
65 posts
 

I should have added, that I had a whole house surge suppressor in place on the outside panel also.

erik_squires OP
15,742 posts
 

I’d like to second your callout regarding surge suppression and LAN protection from your blog. A few months ago we had lightning hit a tree that was just 15 feet from our electrical entrance with is underground.

 

@upshift Sorry to hear that but really interesting.

 

I want to warn you not to use grounding Ethernet arrestors inside your home. Use those, if any, outside or as close to that edge. Inside stick to isolators. The most recent thinking I’ve seen is that grounding Ethernet cables during a surge just allows a high current surge to form through MORE devices when otherwise you wouldn’t have one. Better to isolate the gear and let lightning find a path through a single device and it’s power cable than to form a long circuit and let it take out even more devices downstream. So far during the worst of the lightning I’ve only lost a cable modem, which wasn’t mine anyway. 😁

Alternatively, use fiber converters to air-gap your gear.

After installing my whole-house suppressor lightning took out a laptop. It was the only PC in my home that was plugged in but NOT on a surge strip.

The same way audiophiles are kind of ridiculous with having too much gear to play music, we also have a lot more Ethernet devices hooked up than the average person, though hard core gamers are close.  For many Americans who have Internet access Wifi is the only connection they use and lightning is not the same problem than for someone like me who has a dozen items hooked up via copper networking cables.

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