On Monday, February 10, 2014 3:34:29 PM UTC-5, Bob_Villa wrote:
On Monday, February 10, 2014 1:31:37 PM UTC-6, wrote:



From the PDF:

"2.5.2 Limitations of Panel SPDs

SPDs discussed here, and depicted in Figure 6A, are designed to protect against

very brief surges from lightning and surges from utility switching transients or

other overvoltages much shorter than one second. They are very effective in this

role. However, none of the standard SPDs available as panel protectors for

residential applications offer useful protection against sustained overvoltages

arising from open neutral conductors, high-voltage power crosses, or utility

regulator failure". Note: "very brief surges from lightning..."



Smoke and mirrors

It's not smoke and mirrors. The nature of lightning surges on
powerlines, which has been well researched and documented, is that they
are very brief. They only last from 10 microseconds to less than a
milisecond. That is very brief and exactly what all surge protectors
are designed to deal with. There are UL and ANSI standards for
testing that define real world surges that are typically seen on
power lines and surge protectors are tested in simulators to
verify that they meet those standards.

What they are saying in that section is that all surge protectors,
whether panel mounted or the plug-ins that you apparently believe
work, are effective only for short duration surges. They all
will fail if subjected to basically continous overload from
high voltage power crosses, unregulated utility power, etc. A
surge protector that can take a 5000V 10K amp lightning surge
for 30 microseconds, can't take 700V 100 amps applied for 1 min
from crossed utility wires. That is what they are saying and
it applies not only to surge protectors at the panel, but also
to the plug-ins, which you apparently believe work. The
plug-ins typically use the same electronic components that
a panel protector uses, only much smaller ones, capable of
only handling smaller surges. That's the concept behind the
tiered stategy. A whole house surge protector at the panel
takes most of the surge, plug-ins where they are used deal with
whatever makes it past the panel one, followed by surge protection
in the appliance itself, which can deal with small surges too.
All of those are effective with brief surges, typical of real
world lightning hitting the utility wires down the block.
None of them will be effective against the long duration
overvoltage caused by crossed utility lines, etc.