w_tom wrote:
On Jul 13, 10:45 pm, Jay1028 wrote:
Rods are 8ft, 5/8" galvanized with bronze clamps.. I Live in
northeast Florida near Marineland.
First, even effective surge protectors do not stop typically
destructive surges. One that implies protection forgets to mention it
protects from surges that typically don't damage - surges that don't
overwhelm protection already in all appliances.
The best information on surges and surge protection I have seen is form
the IEEE:
http://omegaps.com/Lightning%20Guide...ion_May051.pdf
And also the NIST:
http://www.nist.gov/public_affairs/p.../surgesfnl.pdf
The IEEE guide is aimed at those with some technical background. The
NIST guide is aimed at the unwashed masses.
For us surges coming in on US power wires, common mode surges are
converted to transverse mode by the neutral-ground bond at the service.
In any case, plugin suppressors have MOVs from H-N, H-G, N-G. That
covers all surge modes.
What determines the effectiveness of that 'whole house' protector?
Quality of earthing and connection to earthing.
w_ has a religious belief (immune from challenge) that surge protection
must use earthing. Thus in his view plug-in suppressors (which are not
well earthed) can not possibly work. The IEEE guide explains plug-in
suppressors work by CLAMPING the voltage on all wires (signal and power)
to the common ground at the suppressor. Plug-in suppressors do not work
primarily by earthing. The guide explains earthing occurs elsewhere.
(Read the guide starting pdf page 40).
Note that all interconnected equipment needs to be connected to the same
plug-in suppressor, or interconnecting wires need to go through the
suppressor. External connections, like phone, also need to go through
the suppressor (as Leonard said). Connecting all wiring through the
suppressor prevents damaging voltages between power and signal wires.
These multiport suppressors are described in the IEEE guide.
According to NIST guide, US insurance information indicates equipment
most frequently damaged by lightning is
computers with a modem connection
TVs, VCRs and similar equipment (presumably with cable TV
connections).
All can be damaged by high voltages between power and signal wires.
Another important protection element, referred to by someone else, is
single point ground. The most important part of a single point ground is
that phone, CATV, ... protection blocks connect with a *short* ground
wire to the earthing wire at the power service. With a large surge there
will always be a difference from the house ground to ‘absolute’ ground.
The goal is for the power, CATV and phone 'grounds' to rise together.
The author of the NIST guide wrote “the impedance of the grounding
system to ‘true earth’ is far less important than the integrity of the
bonding of the various parts of the grounding system.”
In many houses the phone, CATV service entry are distant from the power
service. The IEEE guide (starting pdf page 40) provides an example of
what can happen if the interconnecting wires are too long. In that case
the IEEE guide says "the only effective way of protecting the equipment
is to use a multiport protector." (But another method is to run the
phone wire from the entry NID to the power service area and install a
2nd NID, then distribute the phone wires from there.)
Meanwhile, where does that Panamax even discuss earthing? It does
not because it does not even claim to protect from surges that
typically damage household appliances. No earth ground means no
effective protection.
The religious belief in earthing again.
And the myth of the magic damaging surge again.
Both the IEEE and NIST guides say plug-in suppressors are effective.
Ratings range from junk to very high.
The IEEE guide lists earthing, single point ground, power service
surge suppression, and plug-in suppressors as protection elements. If I
was in high lightning areas I would use them all.
It is not obvious what the Power Sentry reference to 2ms is about. A
surge will be over far before 2 ms. It could be that the Power Sentry
will disconnect if there is overvoltage for 2 ms.
(The author of the NIST guide wrote "in fact, the major cause of TVSS
[surge suppressor] failures is a temporary overvoltage, rather than an
unusually large surge.")
---------------------------
I though the ground water was usually near the surface in Florida. Even
if the soil is sand wouldn’t the ground water provide a good ground? (I
have read other reliable sources say resistance to ground is a problem.)
--
bud--