From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id F1E641396D9 for ; Tue, 31 Oct 2017 00:09:34 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 103A4E0DD3; Tue, 31 Oct 2017 00:09:29 +0000 (UTC) Received: from w1.tutanota.de (w1.tutanota.de [81.3.6.162]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 97FE7E0DC2 for ; Tue, 31 Oct 2017 00:09:28 +0000 (UTC) Received: from localhost (unknown [127.0.0.1]) by w1.tutanota.de (Postfix) with ESMTP id 0BB42FB1E11 for ; Tue, 31 Oct 2017 00:09:26 +0000 (UTC) Received: from w1.tutanota.de ([127.0.0.1]) by localhost (w1.tutanota.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id FoY43roKZdft for ; Tue, 31 Oct 2017 01:09:25 +0100 (CET) Received: from w1.tutanota.de (unknown [192.168.1.162]) by w1.tutanota.de (Postfix) with ESMTP id 5E1E7FB1E3F for ; Tue, 31 Oct 2017 00:09:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=tutanota.com; s=20161216; t=1509408565; bh=0Q3tfjxwV4SR/GaO0yZNcamvxS5VLzXxlFPNnYhfcVo=; h=Date:From:To:In-Reply-To:References:Subject:From; b=UaQ+4/Pjkm223mIpFUlTyHF51wZtW5dEmGC4QZ5L4zHEFsQFVxthy5UyGfPnM0C48 y+7y+OXl4mCJidj2LTr4jaCzk02DfIP2E4NKoysYq86MrVHsJHK6QFvXH0HqFYgFxJ CEl0xkuqcDcE/H5W2QOPMjygTn8GNc2pXoWwfy/Ip7bTeGZD62SOzZNoPY6yXUSETg gisJGT1e0s1jKAeFHzMipBhjRZkga3HQ9Q4dmiH5wYbcVLVVZIhe1RR8NeXeT/wIFc aArHXrxUgFMIRlK+pMgtZNnxDE9LejO8m+4gGyWEveiYOHfrK2RlgqeTW1VAA3at73 B2CRo8KjQYNgw== Date: Tue, 31 Oct 2017 01:09:25 +0100 (CET) From: To: Message-ID: In-Reply-To: <11705523.yOAOuWsGJo@dell_xps> References: <1922379.ZbMImBqxyj@dell_xps> <20a51a10-2c3b-bbcf-ab4e-98f8d2676fe5@gmail.com> <19e3d78e-b284-94f8-1a16-c43b1a478193@gmail.com> <1565551.YJXxyvGCCV@dell_xps> <27a82600-717b-0076-cb75-29e67a7f4ed1@gmail.com> <59F62591.2070003@youngman.org.uk> <<59F62591.2070003@youngman.org.uk>> <924d1b49-16ef-52ce-57c2-5f6e838cbf8d@gmail.com> <<924d1b49-16ef-52ce-57c2-5f6e838cbf8d@gmail.com>> <20171030091007.03b2076d@peak.prhnet> <<20171030091007.03b2076d@peak.prhnet>> <71878972.4tTIccPE0R@dell_xps> <<71878972.4tTIccPE0R@dell_xps>> <514fb8df-3d93-7368-963b-41dcb08762ce@gmail.com> <<514fb8df-3d93-7368-963b-41dcb08762ce@gmail.com>> <2704889.g4SM65V9YC@dell_xps> <<2704889.g4SM65V9YC@dell_xps>> <> <> <> <11705523.yOAOuWsGJo@dell_xps> Subject: Re: [gentoo-user] Alternatives to knutclient Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_208907_545913221.1509408565357" X-Archives-Salt: 2b941f02-a707-4da3-87c4-1f7adde5a008 X-Archives-Hash: 54ac6e4855b1da26a8be437167495a4b ------=_Part_208907_545913221.1509408565357 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable no, varistors (what's in nearly all surge suppressors) either clamp the vol= tage at about twice what it should be, or fail shorted which they tend to d= o eventually (harmlessly blowing a fuse hopefully).=C2=A0=C2=A0=20 the issue is with plugging one thing, into another, into another and then i= nto the wall, most outlet strips are cheap, they don't use proper sockets a= nd often have/develop a significant resistance, which creates a hazard etc.= =C2=A0 Outlet strips also tell you not to plug one into the another, in thi= s case it's the resistance problem and the risk that some consumers will ru= n outlet strips all along a wall etc. pluged one into the other, which will= eventually cause problems, because no one maintains outlet strips and few = keep them clean and dry (it's easy to imagine someone in an older apartment= having 10+ strips plugged into each other).=C2=A0=C2=A0 And that's without= pets, cat's for one have been known to urinate on outlets when mad, doesn'= t hurt an isolated cat but plays havoc with the outlet besides smelling ter= rible (likely the cats' motive).=C2=A0=C2=A0 The reason newer houses have s= o many outlets is precisely to discourage the use of extension cords and pr= event fires, an outlet strip isn't much better, and the fuse/breaker in any= device only offers short circuit protection, a small overload or partial s= hort in the load won't do it (unless you choose fuses/breakers very near th= e rated current, in which case you get nuisance blows/trips).=C2=A0 note th= at when the connectors develop a higher resistance that the current actuall= y decreases, but the energy dissipated in the connection produces excessive= heat, which generally drives resistance higher until there's enough to sta= rt a fire or be noticed.=C2=A0 the varistors are not the problem, note that= computer power supplies and many peripherals include varistors for surge s= uppression and don't cause ups problems. on the other hand, you probably shouldn't use gas arrestors after an ups, w= hen they conduct they short hard (gas plasma) and show a negative dynamic r= esistance which is a really good way to make something oscillate (not good = for the ups) and definately will produce an excessive load for half a power= cycle.=C2=A0=20 gas arrestors are slower, but have unlimited short capacity, MOVs are faste= r but can absorb less energy typically.=C2=A0 Thats why really good multist= age arrestors use both, the MOVs conduct quickly and help limit the peak vo= ltage, then the gas discharge tubes conduct and take most of the surge ener= gy.=C2=A0 either/both on the input side of the ups won't cause problems (an= d will help protect the ups), on the output side gas discharge tubes would = be bad, varistors are fine at least until they short and blow a fuse,=C2=A0= that's what fuses are for.=C2=A0 there is a slight problem that some varis= tors start getting hot under normal conditions (failing but not yet shorted= ) which is why the manufacturers recomend adding a series thermal fuse ther= mally coupled to the varistor to disconect them in this case (and ideally t= he load depending on how things are wired). There are actually multistage devices that can protect low voltage lines (i= .e. control lines on a transmitter tower) from a direct lightning strike as= suming they have a good enough ground connection.=C2=A0 of course it's like= ly to destroy the surge arrestor, which isn't cheap, but it protects far mo= re expensive equipment when it self sacrifices.=20 mad.scientist.at.large (a good madscientist) -- "The U.S. intelligence community concluded in a report made public in Janua= ry that the Kremlin sought to disrupt the 2016 election and sway the race i= n Trump's favor."=C2=A0 From "thehill.com".=20 30. Oct 2017 17:39 by michaelkintzios@gmail.com: > On Monday, 30 October 2017 21:01:35 GMT Dale wrote: >> While it is usually plugged into a surge strip already, >> the more the better. Actually, surge at the wall, UPS, then another >> surge strip that all my stuff plugs into. > > I'm sure I have read in some UPS manual that it should be plugged directl= y=20 > into the mains socket and not via a surge protector. I assumed the manua= l=20 > stated this because when the varistors in the surge protector start condu= cting=20 > excess current during a surge, this could start competing against the AVR= in=20 > the UPS, flipping the battery on/off and perhaps causing a race condition= . I=20 > haven't looked into it, but that's how I perceived it at the time. > > Of course we're talking of normal transients here, not a direct hit by a= =20 > lightning! LOL! > --=20 > Regards, > Mick ------=_Part_208907_545913221.1509408565357 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable no, varistors (what's in nearly all surge suppressors) either clamp the vol= tage at about twice what it should be, or fail shorted which they tend to d= o eventually (harmlessly blowing a fuse hopefully).  

the issue is with plugging one thing, into another, into another and then = into the wall, most outlet strips are cheap, they don't use proper sockets = and often have/develop a significant resistance, which creates a hazard etc= .  Outlet strips also tell you not to plug one into the another, in th= is case it's the resistance problem and the risk that some consumers will r= un outlet strips all along a wall etc. pluged one into the other, which wil= l eventually cause problems, because no one maintains outlet strips and few= keep them clean and dry (it's easy to imagine someone in an older apartmen= t having 10+ strips plugged into each other).   And that's withou= t pets, cat's for one have been known to urinate on outlets when mad, doesn= 't hurt an isolated cat but plays havoc with the outlet besides smelling te= rrible (likely the cats' motive).   The reason newer houses have = so many outlets is precisely to discourage the use of extension cords and p= revent fires, an outlet strip isn't much better, and the fuse/breaker in an= y device only offers short circuit protection, a small overload or partial = short in the load won't do it (unless you choose fuses/breakers very near t= he rated current, in which case you get nuisance blows/trips).  note t= hat when the connectors develop a higher resistance that the current actual= ly decreases, but the energy dissipated in the connection produces excessiv= e heat, which generally drives resistance higher until there's enough to st= art a fire or be noticed.  the varistors are not the problem, note tha= t computer power supplies and many peripherals include varistors for surge = suppression and don't cause ups problems.

on the other hand, you= probably shouldn't use gas arrestors after an ups, when they conduct they = short hard (gas plasma) and show a negative dynamic resistance which is a r= eally good way to make something oscillate (not good for the ups) and defin= ately will produce an excessive load for half a power cycle. 
gas arrestors are slower, but have unlimited short capacity, MOVs are f= aster but can absorb less energy typically.  Thats why really good mul= tistage arrestors use both, the MOVs conduct quickly and help limit the pea= k voltage, then the gas discharge tubes conduct and take most of the surge = energy.  either/both on the input side of the ups won't cause problems= (and will help protect the ups), on the output side gas discharge tubes wo= uld be bad, varistors are fine at least until they short and blow a fuse,&n= bsp; that's what fuses are for.  there is a slight problem that some v= aristors start getting hot under normal conditions (failing but not yet sho= rted) which is why the manufacturers recomend adding a series thermal fuse = thermally coupled to the varistor to disconect them in this case (and ideal= ly the load depending on how things are wired).

There are actual= ly multistage devices that can protect low voltage lines (i.e. control line= s on a transmitter tower) from a direct lightning strike assuming they have= a good enough ground connection.  of course it's likely to destroy th= e surge arrestor, which isn't cheap, but it protects far more expensive equ= ipment when it self sacrifices.

mad.scientist.at.large (a good = madscientist)
--
"The U.S. intelligence community concluded in a report made publ= ic in=20 January that the Kremlin sought to disrupt the 2016 election and sway=20 the race in Trump's favor."  From "thehill.com".
=

30. Oct 2017 17:39 by michaelkintzios@gmail.com= :

On Monday, 30 Oc= tober 2017 21:01:35 GMT Dale wrote:
While it is usually plugged = into a surge strip already,
the more the better. Actually, surge at t= he wall, UPS, then another
surge strip that all my stuff plugs into.
I'm sure I have read in some UPS manual that it should be = plugged directly
into the mains socket and not via a surge protector.= I assumed the manual
stated this because when the varistors in the = surge protector start conducting
excess current during a surge, this = could start competing against the AVR in
the UPS, flipping the batter= y on/off and perhaps causing a race condition. I
haven't looked into= it, but that's how I perceived it at the time.

Of course we're = talking of normal transients here, not a direct hit by a
lightning! = LOL!
--
Regards,
Mick
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