On 6/19/2013 6:44 AM, westom wrote:
> On Wednesday, June 19, 2013 12:45:08 AM UTC-4,
>> I'm thinking we need some kind of really strong voltage
>> control item on our comps and a few other things around here.
>> Any suggestions?
Excellent information on surges and surge protection is at:
- "How to protect your house and its contents from lightning: IEEE guide
for surge protection of equipment connected to AC power and
communication circuits" published by the IEEE (the IEEE is a major
organization of electrical and electronic engineers).
- "NIST recommended practice guide: Surges Happen!: how to protect the
appliances in your home" published by the US National Institute of
Standards and Technology
The IEEE surge guide is aimed at people with some technical background.
======================= From the description this was something more like crossed power wires.
That is not a "surge", which is, by definition, a very short event. As
JohnG wrote, ask the utility if they had an 'incident'.
> Those power strips did exactly what they claim to do. They protect
> only from transients that
> typically do no damage.
> And are so grossly undersized as to fail even on transients that are
> small to damage other appliances.
More complete nonsense.
Contrary to westom's beliefs, which he compulsively spreads all over the
internet, both the IEEE and NIST surge guides say plug-in protectors are
When using a plug-in protector all interconnected equipment needs to be
connected to the same protector. External connections, like coax, also
must go through the protector
> Utility equipment can detect faults (ie a lightning strike).
> Temporarily disconnects power
> (ie because voltages are out of spec). And then automatically
> restore power a few seconds later
> after the fault has cleared. That would be what you observed.
A lighting strike is not a fault.
Sounds like a "recloser", that does open on faults and may reclose
Service panel protectors are very effective against very high current
but very short duration surges. They will be rapidly burned out by the
much longer duration of a crossed power wire. See the IEEE surge guide
pages 11, 15 and 25.
The same is true of plug-in protectors. There are supposed to be
plug-in protectors that disconnect on overvoltage - I haven't seen them.
A UPS may disconnect and provide protection (and apparently they did).
(Disconnecting to protect from a surge doesn't work because a surge is
too short an event.)
The author of the NIST surge guide has written "the major cause of
[surge protector] failures is a temporary overvoltage, rather than an
unusually large surge."
> Destructive transients occur maybe once every seven years. Typically
> may be hundreds of
> thousands of joules. And are not averted by any 'box'.
It has been explained to westom many times that not much surge energy
can make it to a plug-in protector, and also explained why. But westom
ignores anything that does not fit his very limited beliefs on protection.
> Even the power strip needs protection provided by earthing one 'whole
> house' protector.
More complete nonsense.
SquareD does not make plug-in protectors, but says for their "best"
service panel protector "electronic equipment may need additional
protection by installing plug-in [protectors] at the point of use."
> Because a protector is only as effective as its earth ground.
It is westom's mantra that protects him from confusing thoughts (aka
Unfortunately for westom, the IEEE surge guide explains (starting page
30) that plug in protectors do not work primarily by earthing surges.
Earthing occurs elsewhere. Plug-in protectors work by limiting the
voltage from each wire (power and signal) to the ground at the
protector. The voltage between the wires going to the protected
equipment is safe for the protected equipment.
For real science, and excellent information on surge protection, read
the IEEE and NIST surge guides.