On Saturday, October 17, 2015 at 7:44:58 AM UTC-5, westom wrote:
On Friday, October 16, 2015 at 9:09:12 PM UTC-4, Gz wrote:
The supo type I've seened used in main breaker box on show Holmes on Homes.
I do not like the fact it uses stranded wire for breaker use.

Lightning is typically 20,000 amps. So a minimal 'whole house' protector should be at least 50,000 amps. No protector should fail during a direct lightning strike or other surge. If its indicator light reports a failure, that protector was grossly undersized. Replacement may need be larger.

Each layer of protection is only defined by what a protector connects to - earth ground. A protector in the breaker box should be quite effective due to earth ground rods connected low impedance (ie less than 10 feet away) by a hardwire (a bare copper, quarter inch copper wire).

Each layer of protection is only defined by what harmlessly absorbs hundreds of thousands of joules - earth ground. Above only discusses 'secondary' protection. Also inspect your 'primary' surge protection layer. A picture demonstrates what to inspect:
http://www.tvtower.com/fpl.html

Protection is only provided by what harmlessly absorbs hundreds of thousands of joules. No protector does that. An effective protector is only a connecting device wired low impedance (no sharp wire bends) to earth ground. A protector is only as effective as its earth ground. That is protection during each surge. 50,000 amps defines protector life expectancy over many surges.

No protector should ever fail catastrophically like that. Either is was grossly undersized, not properly earthed, or a 'primary' protection layer was missing.

I read something about government studies concerning surge arresters protecting facilities from EMP and it involved layers of protection. Surge protection where power entered the building and at every breaker panel and device down the line. Here in town, an electronics company I dealt with sold a bunch of high end surge arresters to a cellphone company for their sites. Lightning strikes would often blow the hell out of the surge arrestors but none of the very expensive equipment was ever damaged. Hummm, let me see. a $100 dollar surge arrester or a $100,000 piece of electronic gear. I'll have to think about which one I'm concerned about losing. o_O

[8~{} Uncle Surge Monster