nanog mailing list archives

Re: Why choose 120 volts?


From: david raistrick <drais () icantclick org>
Date: Wed, 27 May 2009 18:30:20 -0400 (EDT)

On Wed, 27 May 2009, Seth Mattinen wrote:

Here's the L-G voltage off the 208v taps from an isolation transformer in a system with no neutral: http://ninjamonkey.us/not_120_volts.jpg

Not 120, but 90 give or take. 90 is at the low end of the acceptable range for common household 110/120v service.

Depending on how the phases are balanced in your facility, you may see that fluctuate up or down, of course. If you measure hot to hot on the same PDU, do you get anywhere close to 208? I'm going to suspect either your fairly out of balance, or you've got a good bit of voltage drop by the time it arrives....


But since the concensus from those who haven't used this is that the device will present 208/240 at the 5-15 plug, I withdraw my suggestion and leave you to your own methods. (for the rest, test it yourself)

I also won't argue using ground for neutral, that's like arguing bonded vs unbonded panels.



---
david raistrick        http://www.netmeister.org/news/learn2quote.html
drais () icantclick org             http://www.expita.com/nomime.html



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