nanog mailing list archives
Re: Want to move to all 208V for server racks
From: "Kevin Oberman" <oberman () es net>
Date: Sat, 04 Dec 2010 14:52:09 -0800
Date: Sat, 4 Dec 2010 23:26:46 +0100 (CET) From: Ingo Flaschberger <if () xip at>There's also a telco oriented 48V inverter rack system thats escaping my mind at the moment. It can be setup with A/B 48V strings, and you plug in inverter modules up to IIRC around 8kW. Not parallel capable between racks AFAIK.48V (and some more when batteries are full) are slightly below the limit of non harmfull voltage. Thus you have a voltage with less power loss at short transports and a secure voltage. (creating a short is still not a great idea).
Saying that 48V is not a harmful voltage is a very dangerous statement. It is unlikely to be a threat of electrocution (though even that has exceptions), but people have lost fingers to 12V systems. Lead-acid batteries can deliver way over 100 amps of current and a conductor across "safe" voltage will get hot and, if not heavy enough, will vaporize. The temperatures attained can cause major burns and, should the metal vaporize, can damage tissue so severely that fingers have been lost when the blood vessels were cauterized. While safety rules often list voltages under 50 as being safe, it is still important to exercise caution like removing rings, bracelets and the like. -- R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman () es net Phone: +1 510 486-8634 Key fingerprint:059B 2DDF 031C 9BA3 14A4 EADA 927D EBB3 987B 3751
Current thread:
- Re: Want to move to all 208V for server racks, (continued)
- Re: Want to move to all 208V for server racks Owen DeLong (Dec 03)
- Re: Want to move to all 208V for server racks Gary Buhrmaster (Dec 04)
- Re: Want to move to all 208V for server racks Jima (Dec 03)
- Re: Want to move to all 208V for server racks Joel Jaeggli (Dec 03)
- Re: Want to move to all 208V for server racks Jima (Dec 03)
- Re: Want to move to all 208V for server racks Jay Ashworth (Dec 03)
- Re: Want to move to all 208V for server racks Michael Loftis (Dec 04)
- Re: Want to move to all 208V for server racks Jay Ashworth (Dec 04)
- Re: Want to move to all 208V for server racks Michael Loftis (Dec 04)
- Re: Want to move to all 208V for server racks Ingo Flaschberger (Dec 04)
- Re: Want to move to all 208V for server racks Kevin Oberman (Dec 04)
- Re: Want to move to all 208V for server racks Michael Painter (Dec 04)
- Re: Want to move to all 208V for server racks Lamar Owen (Dec 06)
- Re: Want to move to all 208V for server racks Gary Buhrmaster (Dec 04)
- Re: Want to move to all 208V for server racks Seth Mattinen (Dec 02)
- Re: Want to move to all 208V for server racks Gary Buhrmaster (Dec 03)
- Re: Want to move to all 208V for server racks Gary Buhrmaster (Dec 03)
- Re: Want to move to all 208V for server racks Jay Ashworth (Dec 03)
- Re: Want to move to all 208V for server racks Leo Bicknell (Dec 03)
- Re: Want to move to all 208V for server racks Ingo Flaschberger (Dec 03)
- RE: Want to move to all 208V for server racks Alex Rubenstein (Dec 03)