"James Wilkinson Sword" writes:

On Wed, 08 Feb 2017 22:13:00 -0000, Phil Hobbs wrote:

On 02/08/2017 05:00 PM, James Wilkinson Sword wrote:
On Wed, 08 Feb 2017 21:55:06 -0000, Phil Hobbs
wrote:

On 02/08/2017 02:46 PM, James Wilkinson Sword wrote:
On Wed, 01 Feb 2017 17:31:50 -0000, Mr. Man-wai Chang
wrote:

A small town's sudden power surge fried tech gear in hundreds of homes


You should have anything expensive in a UPS.


Big help if the house burns down.

I've heard of folks getting MOVs put in right at the meter, outside the
house. In that sort of super nasty surge, they explode and isolate the
house from the line. Never had the urge to do it myself, but it might
be good insurance.

Wouldn't a really big surge destroy the first thing it hits, i.e. the
main fuse, meter, etc?


It matters where the big arc happens, though. You don't clear a high
energy 1600-4800V circuit with a domestic 240V breaker, that's for sure.
The result is an _arc flash_, which you do _not_ want in your
vicinity, trust me. (Youtube has a lot of examples if you doubt this.)

Having a major league arc flash on a cinderblock foundation outside the
house is a very different proposition from having one in a breaker box
mounted to a wooden stud wall inside, for one thing, but I'm outside my
experience here, so I'll happily defer to any actual power engineering
types who want to chime in.

I can't believe it's that likely for 4800V to get onto a 240V line. Possible, but so rare it's not worth bothering to install protection. I protect against little spikes, or voltages about 30V under/over what they should be. My UPS frequently adjusts the voltage, and sometimes gives up and runs the house on batteries for 5 seconds.

Well, it did happen to us. The pole with the transformer broke between the
transformer and the crossarm at the top, partly because it was an old pole
with ants living in the part that broke and partly because of the winter
storm. I saw the aftermath and even still have the two 4800V cutouts
that fed the transformer. This was a bunch of summer cottages on a lake.
Two of them burned to the ground. Our place was on the same transformer
but because my father always threw the main breaker when closing up the
place it was unaffected.