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Join Date: Jan 2016
Location: Houston
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Quote:
Originally Posted by westom View Post
Apparently you believe a UPS will somehow 'block' a surge. It will not. It does not claim to.

Those 2 cm disks inside a power strip are superior to protection provided by a UPS.
Actually, FWIW, my consumer grade UPSs do claim surge protection. And they appear to provide it by using the same varistors that the power strips use. Are they a perfect solution? Well, they didn't save my networking equipment... I'm curious as to why you say above they can make the situation worse?

Quote:
Originally Posted by westom View Post
Investigation starts at single point earth ground. Did other earth grounds exist? Did any conductor outside the house enter without making a low impedance (ie less than 10 foot) connection to that earth ground?

Protection is always about connecting a surge on a path that is not destructive.

Effective protection never 'blocks' a surge.
The single point ground rod is interesting to me. My home has a single meter box, two main disconnects, and two main panels -- each has it's own connection to a local ground rod (although the disconnects and meter have the same rod). I just looked at the code/recommended installation online and it looks right to my untrained eye. I'm not sure what else I'm supposed to ground.

You've also got me rethinking the surge protectors I installed (which are at the disconnects for my HVAC units). The more I think about it, these are probably just [big] varistors that look to block the surge through increased resistance. I know you say they can't block a surge, but isn't that exactly what they're supposed to by increasing their resistance with voltage? Do these help or not?

It seems like I should have also installed two whole house surge (4-wire) protectors (one at each main panel). Perhaps those would have better grounded any voltage spikes (at the respective panels) before looking for a path to ground on the circuit branches? Something like this?: https://www.amazon.com/Siemens-FS140-Whole-Protection-Device/dp/B013WINMK6

And while you're sharing your knowledge on lightning/surge protection, what are your thoughts on metal roofs, and how should they be grounded (if at all)?
Old 11-11-2018, 10:10 AM
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