On 5/30/24 06:30, Roger Price wrote:
On Wed, 29 May 2024, David Christensen wrote:
On 5/29/24 03:36, Roger Price wrote:
On Tue, 28 May 2024, David Christensen wrote:
On 5/28/24 00:28, Roger Price wrote:
I wired my place Cat5. A lot of work, and I regretted it. I live
in the hills behind Nice, an area with a lot of lightning. The
overhead line to my place took a hit and thanks to the Cat5
conductivity I lost equipment.
How do you know that the damage your equipment suffered was due to
the Cat 5e wiring and not due to the electrical power conductors?
Electrical power to my computers comes through 30mA differential
circuit breakers to Eaton Ellipse 1600 UPS units. I had no such
protection for the telephone signal, and I saw flashes at the
telephone junction box. So I summise that the Cat5 wiring did the
damage.
Those UPS's should be able to protect telephone and Ethernet, in
addition to electrical power. Have you applied the UPS's to the
former two?
The UPS's stand next to the workstations and well away from the place
where the telephone line arrives, so I didn't use the UPS's to protect
the telephone line. My fault. Later I added a surge protector to the
copper telephone line. I am now in the process of migrating from copper
to fiber so I will need an extra UPS next the fiber terminator.
Roger
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https://www.eaton.com/sg/en-us/catalog/backup-power-ups-surge-it-power-distribution/eaton-ellipse-pro-ups.html
PS: I once had a lightning strike direct to the house. Frightening.
Although every differential circuit breaker in the house tripped, the
circuit board in the UPS melted. But even when melting, it protected
the Dell T7500. No damage to the T7500, no data lost. I took a photo of
the melt, sent it to Eaton, and they replaced the UPS.
Since I did the grounding rebuild in 2008, I have seen the pole that
supplies my house drop, take a direct hit at least twice. I've had zero
damage. I've even been personally tapped once typeing on a wired
keyboard. Amazingly the keyboard survived. The secret is that the whole
house jumps maybe 100k volts in unison. There is little differential
voltage to blow things. The NEC does know a thing or two about
grounding. That and probably a kilojoule of surge absorbers that break
down at around 180 volts differential. I did trip a 20 amp breaker,
years ago, feeding my go704 mill which was on at the time. It has a
motor power supply from hell and probably helps clamp the differential
voltages on that leg of the power. Turning it on w/o a soft start
circuit trips a 30 amp breaker 100% of the time. The PMDC motor it runs
is a 1hp, but I've upped the voltage and currant to about 4 hp over a
decade ago. And its still running on the OEM brushes.
Cheers, Gene Heskett, CET.
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
