w_tom wrote:
On May 4, 9:09 pm, "Michael A. Terrell"
wrote:
The same thing we did in the studios and transmitter sites. Use a
combination of protection at the building's main disconnect, and
individual protection at each critical device. The only thing that I've
lost in the last ten years was when lightning hit a huge pine tree, and
cut the top half of it off. It landed on the ground right over the
buried telephone line, and a second strike blew out the modem and MOV
protection on the phone line.
You suffered damage from a lightning strike and call that effective
protection? Modems are most typically damaged by surges entering an
AC mains. Outgoing surge path would be the phone line to earth via a
telco installed 'whole house' protector. Damage from lightning is
effective protection? After spending how much for all those
protectors, you call that protection?
Where did I say HOW was protected? It was my second week at that
station, and the chief engineer took off on a long overdue vacation. If
you would learn to read, rather than just do mindless rants you wouldn't
look so stupid. At that time the building had a UFER ground, and a
three phase protection system at the meter CTs. That didn't prevent the
damage, as you claim it should.
Phone lines do not use MOV protectors. Basic information that you
would have learned if not wasting time insulting people.
Sorry, _wacko_ but you are the one slinging insults and ignoring
proof from hundreds of people.
MOVs have
too much capacitance. Phone line 'whole house' protectors use other
technologies with lower capacitance.
Gee, _wacko_ you've never seen ANY modern business telephone
equipment? Gas tubes are fragile and very expensive. The protection
isn't to save the privately owned telephones, it it to limit damage to
the building. Even that mid '60s 1A2 system had every output of the
power supply fused to prevent a fire. Explain why an MOV's capacitance
is high enough to affect a phone line. Never mind. I have a Nitsuko/NEC
DX2NA-32SYTEMEM KEY TELEPHONE SYSTEM in front of me, and every CO line
in it has a MOV across the line. Once more, you're preaching lies and
using deceit to try to make others look bad.
,http://refurbishednitsuko.net/productInfo.aspx?productID=75978489-9ac8-40c1-9496-559bfc01b4d3
is the Central Office line card for four telephone lines. See the black
MOVs to the right of each pair of fuses?
http://refurbishednitsuko.net/productInfo.aspx?productID=f5453e33-047e-4726-8631-50a929aabedf
is the card for four standard 2500 type telephones, or equivalent
equipment. See the pairs of black MOVs over the blue connectors at the
bottom of the screen? They are all japanese, with no brand markings.
http://www.epcos.com/web/generator/Web/Sections/Publications/PDF/SIOVMetalOxideVaristors,property=Data__en.pdf;/SIOVMetalOxideVaristors.pdf
is the Epcos MOV databook, with datasheets for Telecom applications.
page 213 list the TELECOM MOV data.
Every line into that studio building had a long distance call device
diverter in the line that had MOV across the phone line. Every one of
them survived the direct hit to the building and STL tower. That's more
than can be said of your ability to use reason, and learn new things.
You need to get your head out of 1920 and learn modern electronics.
The one thing we learned today is that you don't know any more about
Telecom that you do lightning protection, or reading comprehension.
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