w_tom wrote:
> Series mode protector will ignore or avoid THE one and essential
> component of an effective protection system - single point earth
> ground.
Indeed. And yes, a high end data center should survive
a lightning strike (as well as hospital's power systems, etc).
Here's a nice article where Suncoast Schools Federal Credit
Union's data center survived a direct lightning strike to
their 480-V service entrance cable. The article spends
a lot of the time talking about the grounding system.
http://www.ecpzone.com/article/article.jsp?siteSection=12&id=41
"Starting from the ground up, the main elements of the
[lightning protection] system...include:
(1) Three 20-ft x 5/8-in (6-m x 16-mm) copper-clad-steel
grounding electrodes [...] The grounding system's resistance
to earth as measured by fall-of-potential testing is 4.3 ohms.
(2) Another 4/0 copper grounding conductor connects the
ground-neutral bus in the service entrance panel to the
ground bus in a 480-V distribution panel ...
(3) Multiple uninterruptible power supplies (UPSs)....
(4) Up to seven layers of voltage surge protection....
High Quality Grounding.... "even the most expensive
TVSS you can buy is absolutely useless unless it sees
a high-quality, low-resistance ground. "
"