From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists.gentoo.org ([140.105.134.102] helo=robin.gentoo.org) by nuthatch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1GBTwM-0007L3-4Y for garchives@archives.gentoo.org; Fri, 11 Aug 2006 10:08:30 +0000 Received: from robin.gentoo.org (localhost [127.0.0.1]) by robin.gentoo.org (8.13.7/8.13.6) with SMTP id k7BA5nsg013819; Fri, 11 Aug 2006 10:05:49 GMT Received: from smtp1.versatel.nl (smtp1.versatel.nl [62.58.50.88]) by robin.gentoo.org (8.13.7/8.13.6) with ESMTP id k7BA2Kxo018985 for ; Fri, 11 Aug 2006 10:02:21 GMT Received: (qmail 8633 invoked by uid 0); 11 Aug 2006 10:02:18 -0000 Received: from ip138-170-173-82.adsl2.versatel.nl (HELO [192.168.26.100]) ([82.173.170.138]) (envelope-sender ) by smtp1.versatel.nl (qmail-ldap-1.03) with SMTP for < >; 11 Aug 2006 10:02:18 -0000 From: Herman Grootaers To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] Re: [Very OT] - Kill-A-Watt (240V Version) to measure my Gentoo Server Power Usage Date: Fri, 11 Aug 2006 12:02:18 +0200 User-Agent: KMail/1.8.2 References: <1154625941.27366.17.camel@neuromancer.home.net> <44D26EB0.1010400@vista-express.com> <44DC4C39.5040608@travellingkiwi.com> In-Reply-To: <44DC4C39.5040608@travellingkiwi.com> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200608111202.18665.herman@grootaers-nl.com> X-Archives-Salt: 1d5f1a80-6934-469d-ba18-fc9c377b8d60 X-Archives-Hash: 984eadbfead8b66674a96ac69cbcb54d On Friday 11 August 2006 11:22, Hamish Marson wrote: > Dale wrote: > > Mike Williams wrote: > >> On Thursday 03 August 2006 19:27, James wrote: > >>> The simplist solution is NOBODY puts a 240 VAC power supply > >>> into a computer unless it's going to draw some serious current > >>> (amps) thus by the nature of it being 240 VAC, you already know > >>> it is a power hog. > >> > >> Now, I'm not electrical engineer, but I know my way around a fuse > >> board and electricity having fitted out both our new offices for > >> power, network, and some walls. > >> > >> In the UK, and most (if not all) of Europe, Africa, and Asia too, > >> run on about 240 volts, 230 +-10% I think now. Pretty much the > >> whole world, except the Americas. > > > > Well, the USA has the same coming in too. We have 220v to 240v > > coming in but that is split into different legs for the 110v to > > 120v stuff. > > Unless those two legs are in phase, you're still only getting > 110V-120V AC. IIRC (And it's from 20 years ago I'm working here) it's > not, it's just two legs of the 3 phase generated power. Which means > they're 120 deg out of phase, and so you still only get 110-120V. In > order to get 220-240V, you'd need 3 phase power. Safer to use a transformer 110V-220V which will lessen the danger of playing with two or three live wires, a misconnection can cause an outage with all sorts of problems generated, died disks and other apparatus. > I suspect you get two 110V lines because of current limitations. Not > to provide you with 220V which you'r enot going to get from just > adding two out of phase lines. (Unless of course the US has wired up > two in-phase separate 110V lines. In which case you can get 220V > outof it, but I seem to remember a lecture in Eng Sci saying it was > common to take 2 of 3 phases to a house in the US & alternate which 2 > between successive houses. > > > If you are using transformers to reduce it from 220v to 110v, that > > will waste some energy right there. Transformers are not real > > efficient. If you touch it and it is warm, that is what you are > > wasting. That will also make whatever you are cooling with work > > harder too. > > Plus you need twice the current at 110V vs 220V. (Volts are big 'V' > BTW! Named after Voltaire). Sorry, the french writer Voltaire was not dabbling in science. It was Alessandro Guiseppe Antonio Volta who detected the reaction of different metals on the muscles of a hindlegs of a frog and build the first electric battery from that detection. > This means higher line losses as loss is proportional to current. > Higher line losses mean that cable length becomes more of a problem. > (A 10V drop in 240V is less than 5%. 10V drop in 120V is almost 10%. > Much more significant). > > All-in-all I prefer 240V single phase. > So do I, although in itself that voltage is deadly -- Herman Grootaers -- gentoo-user@gentoo.org mailing list