Re: Multiple power strips daisy-chained, code?

Steve Sousa wrote:
"bud--" <remove.budnews@xxxxxxx> wrote in message news:dfc15$497df355$cde8d562$15387@xxxxxxxxxxxxxxxx

For reliable information on surges and surge protection read a guide from the US NIST at:
<http://www.nist.gov/public_affairs/practiceguides/surgesfnl.pdf>

Or a more technical guide from the IEEE:
<http://www.mikeholt.com/files/PDF/LightningGuide_FINALpublishedversion_May051.pdf>

Meanwhile, that surge protector did not provide and does not claim
to provide surge protection.
Complete nonsense.

Effective protection has
always been at the breaker box where surges are earthed before
entering the building.
Service panel suppressors are a good idea.
What does the NIST guide say?
"Q - Will a surge protector installed at the service entrance be sufficient for the whole house?
A - There are two answers to than question: Yes for one-link appliances [electronic equipment], No for two-link appliances [equipment connected to power AND phone or cable or....]. Since most homes today have some kind of two-link appliances, the prudent answer to the question would be NO - but that does not mean that a surge protector installed at the service entrance is useless."

Service panel suppressors do not prevent high voltage between power and phone/cable wires. The NIST guide suggests most equipment damage is caused by high voltage between power and signal wires.

Because of 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.

Will that silly little power strip stop what three miles of sky
could not? Of course not. And yet that is what the power strip must
do.
w has a religious belief (immune from challenge) that surge protection must directly 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 (limiting) the voltage on all wires (signal and power) to the common ground at the suppressor. Plug-in suppressors do not work primarily by earthing (or stopping or absorbing or magic). The guide explains earthing occurs elsewhere. (Read the guide starting pdf page 40).

And finally, scary pictures of another problem seen by most
fire departments:
http://www.hanford.gov/rl/?page=556&parent=554
The village idiot ignores what his own hanford link says. It is about "some older model" power strips and says overheating was fixed with a revision to UL 1449 that required thermal disconnects. That was 1998. There is no reason to believe, from any of these links, that there is a problem with suppressors produced under the UL standard that has been in effect since 1998. None of these links even say a damaged suppressor had a UL label.

Responsible companies such as
Siemens, Leviton, Intermatic, Cutler-Hammer (Eaton), Square D, and GE
provide these effective solutions.
And all make plug-in suppressors except SquareD.

For it's "best" service panel suppressor SquareD says "electronic equipment may need additional protection by installing plug-in [surge suppressor] devices at the point of use."


For real science read the IEEE and NIST guides. Both say plug-in suppressors are effective.

There are 98,615,938 other web sites, including 13,843,032 by lunatics, and w can't find another lunatic that agrees with him that plug-in suppressors are NOT effective.

And w can not answer simple questions:
- Why do the only 2 examples of protection in the IEEE guide use plug-in suppressors?
- Why does the NIST guide says plug-in suppressors are "the easiest solution"?
- Why does the NIST guide say "One effective solution is to have the consumer install" a multiport plug-in suppressor?
- Why do w's "responsible companies" make plug-in suppressors?
- Why does "responsible company" SquareD say "electronic equipment may need additional protection by installing plug-in [suppressors] at the point of use"?


What about systems where Neutral is not connected to ground? (europe)
Shall the cable and phone line shields be connected to ground?


I believe there is more than one earthing scheme used. My understanding is that neutrals are earthed somewhere, maybe only at the utility transformer end.
And "ground" might refer to a power system grounding conductor or the earth.

In general, I assume that plug-in suppressors in Europe would have a power "ground" wire (connected to earth), and that at a plug-in suppressor the cable ground would connect to that wire (or could be clamped to it) and all other wires - power, telephone, cable center conductor - are clamped to the same ground/earth wire at the suppressor. That means the voltage between wires going to the protected equipment is safe for the protected equipment.

In the US, I believe connecting the neutral and "ground" wires together at the service and earthing both at the building is an advantage for surge protection. If a strong surge comes in on 'hot' power wire there is arc-over when the voltage from busses to enclosure(/"ground"/neutral/earth) reaches about 6kV (US). When established, the arc voltage is hundreds of volts. This both limits the voltage that the building 'sees' and dumps most of the surge energy to earth.

And the universal US practice of having a phone wire entrance protector that limits the voltage from phone wires to the power ground system is also a major advantage. I believe BT does not usually do that. Don't know about the mainland. US practice also has the cable shield, at building entry, connected to the power ground system. Short connections from phone and cable entry protectors to the system ground at the power system is one of the major protection schemes in the IEEE guide. Currents to earth from a strong surge can lift the building "ground" well above "absolute ground". A significant part of the protection is keeping the power and phone and cable wires near the same potential.

Don't know if that completely answers your question.

--
bud--
.

Relevant Pages

  • Re: NEWEGG Extended Warranty on SAMSUNG
    ... Protection is earth ground. ... The IEEE guide explains plug-in suppressors work by CLAMPING the voltage on all wires to the common ground at the suppressor. ...
    (alt.tv.tech.hdtv)
  • Re: House grounding
    ... The IEEE guide provides an example starting pdf page 40. ... only as effective as its earthing. ... The IEEE guide explains plug-in suppressors work by CLAMPING the voltage on all wires to the common ground at the suppressor. ... Point of entry protection can provide good protection, but it can not provide protection from internal sources. ...
    (alt.home.repair)
  • Re: MOVs and surge suppressors
    ... Both say plug-in suppressors are effective. ... protection in the IEEE guide use plug-in suppressors. ... The IEEE guide explains plug-in suppressors work by CLAMPING the voltage on all wires to the common ground at the suppressor. ...
    (sci.electronics.basics)
  • Re: "chain" surge suppressers?
    ... "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 in 2005. ... The IEEE guide explains plug-in suppressors work by CLAMPING the voltage on all wires to the common ground at the suppressor. ...
    (alt.home.repair)
  • Re: Surge Protector for Friederich 24k btu Wall A/C Unit - Is it okay to use?
    ... Excellent information on surges and surge protection is in an IEEE guide at:http://omegaps.com/Lightning%20Guide_FINALpublishedversion_May051.pdf ... The IEEE guide is aimed at those with some technical background. ... The IEEE guide explains plug-in suppressors work by CLAMPING the voltage ...
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